[Federal Register Volume 81, Number 224 (Monday, November 21, 2016)]
[Proposed Rules]
[Pages 83556-83615]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-26962]
[[Page 83555]]
Vol. 81
Monday,
No. 224
November 21, 2016
Part V
Consumer Product Safety Commission
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16 CFR Part 1241
Safety Standard for Portable Generators; Proposed Rule
Federal Register / Vol. 81 , No. 224 / Monday, November 21, 2016 /
Proposed Rules
[[Page 83556]]
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CONSUMER PRODUCT SAFETY COMMISSION
16 CFR Part 1241
[Docket No. CPSC-2006-0057]
RIN 3041-AC36
Safety Standard for Portable Generators
AGENCY: Consumer Product Safety Commission.
ACTION: Notice of proposed rulemaking.
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SUMMARY: The U.S. Consumer Product Safety Commission has determined
preliminarily that there may be an unreasonable risk of injury and
death associated with portable generators. To address this risk, the
Commission proposes a rule that limits CO emissions from operating
portable generators. Specifically, the proposed rule would require that
portable generators powered by handheld spark-ignition (SI) engines and
Class I SI engines not exceed a weighted CO emission rate of 75 grams
per hour (g/hr); generators powered by one-cylinder, Class II SI
engines must not exceed a weighted CO emission rate of 150 g/h; and
generators powered by Class II SI engines with two cylinders must not
exceed a weighted emission rate of 300 g/h.
DATES: Submit comments by February 6, 2017.
ADDRESSES: You may submit comments, identified by Docket No. CPSC-2006-
0057, by any of the following methods:
Electronic Submissions: Submit electronic comments to the Federal
eRulemaking Portal at: http://www.regulations.gov. Follow the
instructions for submitting comments. The Commission does not accept
comments submitted by electronic mail (email), except through
www.regulations.gov. The Commission encourages you to submit electronic
comments by using the Federal eRulemaking Portal, as described above.
Written Submissions: Submit written submissions by mail/hand
delivery/courier to: Office of the Secretary, Consumer Product Safety
Commission, Room 820, 4330 East West Highway, Bethesda, MD 20814;
telephone (301) 504-7923.
Instructions: All submissions received must include the agency name
and docket number for this notice. All comments received may be posted
without change, including any personal identifiers, contact
information, or other personal information provided, to: http://www.regulations.gov. Do not submit confidential business information,
trade secret information, or other sensitive or protected information
that you do not want to be available to the public. If furnished at
all, such information should be submitted in writing.
Docket: For access to the docket to read background documents or
comments received, go to: http://www.regulations.gov, and insert the
docket number CPSC-2006-0057, into the ``Search'' box, and follow the
prompts.
FOR FURTHER INFORMATION CONTACT: Janet Buyer, Project Manager,
Directorate for Engineering Sciences, Consumer Product Safety
Commission, 5 Research Place, Rockville, MD 20850; telephone: 301-987-
2293; email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Background
A portable generator is an engine-driven machine that converts
chemical energy from the fuel powering the engine into rotational
energy, which, in turn, is converted to electrical power. Reports of
portable generator-related fatalities and injuries prompted the U.S.
Consumer Product Safety Commission (Commission or CPSC) to publish an
advance notice of proposed rulemaking (ANPR) in December 2006 to
consider whether there may be an unreasonable risk of injury and death
associated with portable generators (71 FR 74472 (December 12, 2006)).
The ANPR began a rulemaking proceeding under the Consumer Product
Safety Act (CPSA). The Commission received 10 comments in response to
the ANPR. Subsequently, in a two-part technology demonstration program,
CPSC contracted with the University of Alabama (UA) to conduct a low CO
emission prototype generator technology development and durability
demonstration and contracted with NIST to conduct comparative testing
of an unmodified carbureted generator and prototype generators in an
attached garage of a test house facility. CPSC staff published a report
regarding the results of the UA technology demonstration and received
12 comments in response to this report. NIST published a report
concerning its comparative testing of generators and received four
comments in response to its report. The Commission is now issuing a
notice of proposed rulemaking (NPR) that would establish requirements
for carbon monoxide emission rates.\1\ The information discussed in
this preamble is derived from CPSC staff's briefing package for the
NPR, which is available on CPSC's Web site at: https://www.cpsc.gov/s3fs-public/ProposedRuleSafetyStandardforPortableGenerators.pdf.
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\1\ The Commission voted (4-1) to publish this notice in the
Federal Register. Chairman Elliot F. Kaye and Commissioners Robert
S. Adler, Joseph P. Mohorovic, and Marietta S. Robinson voted to
approve publication of the proposed rule. Commissioner Ann Marie
Buerkle voted against publication of the proposed rule.
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II. Statutory Authority
Portable generators are ``consumer products'' that can be regulated
by the Commission under the authority of the CPSA. See 15 U.S.C.
2052(a). Section 7 of the CPSA authorizes the Commission to promulgate
a mandatory consumer product safety standard that sets forth certain
performance requirements for a consumer product or that sets forth
certain requirements that a product be marked or accompanied by clear
and adequate warnings or instructions. A performance, warning, or
instruction standard must be reasonably necessary to prevent or reduce
an unreasonable risk or injury. Id.
Section 9 of the CPSA specifies the procedure that the Commission
must follow to issue a consumer product safety standard under section
7. In accordance with section 9, the Commission may commence rulemaking
by issuing an ANPR; as noted previously, the Commission issued an ANPR
on portable generators in December 2006. (71 FR 74472 (December 12,
2006)). Section 9 authorizes the Commission to issue an NPR including
the proposed rule and a preliminary regulatory analysis, in accordance
with section 9(c) of the CPSA and request comments regarding the risk
of injury identified by the Commission, the regulatory alternatives
being considered, and other possible alternatives for addressing the
risk. Id. 2058(c). Next, the Commission will consider the comments
received in response to the proposed rule and decide whether to issue a
final rule, along with a final regulatory analysis. Id. 2058(c)-(f).
The Commission also will provide an opportunity for interested persons
to make oral presentations of the data, views, or arguments, in
accordance with section 9(d)(2) of the CPSA. Id. 2058(d)(2).
According to section 9(f)(1) of the CPSA, before promulgating a
consumer product safety rule, the Commission must consider, and make
appropriate findings to be included in the rule, on the following
issues:
The degree and nature of the risk of injury that the rule
is designed to eliminate or reduce;
the approximate number of consumer products subject to the
rule;
the need of the public for the products subject to the
rule and the
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probable effect the rule will have on utility, cost, or availability of
such products; and
the means to achieve the objective of the rule while
minimizing adverse effects on competition, manufacturing, and
commercial practices.
Id. 2058(f)(1). Under section 9(f)(3) of the CPSA, to issue a final
rule, the Commission must find that the rule is ``reasonably necessary
to eliminate or reduce an unreasonable risk of injury associated with
such product'' and that issuing the rule is in the public interest. Id.
2058(f)(3)(A)&(B). Additionally, if a voluntary standard addressing the
risk of injury has been adopted and implemented, the Commission must
find that:
the voluntary standard is not likely to eliminate or
adequately reduce the risk of injury, or that
substantial compliance with the voluntary standard is
unlikely. Id. 2058(f)(3)(D). The Commission also must find that
expected benefits of the rule bear a reasonable relationship to its
costs and that the rule imposes the least burdensome requirements that
would adequately reduce the risk of injury.
Id. 2058(f)(3)(E)&(F).
III. The Product
A portable generator is an engine-driven machine that converts
chemical energy from the fuel powering the engine to mechanical energy,
which, in turn, is converted to electrical power. The engine can be
fueled by gasoline, liquid propane, or diesel fuel.\2\ A portable
generator has a receptacle panel for connecting appliances or other
electrical loads \3\ via a cord with a plug connection. Portable
generators are designed to be carried, pulled, or pushed by a person.
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\2\ Engines that operate on gasoline or liquid propane are
called spark ignition (SI) engines and engines that operate on
diesel fuel are called compression ignition (CI) engines.
\3\ An electrical load is an electrical component or portion of
a circuit that consumes electric power. This is opposed to a power
source, which produces power, such as a battery or generator.
Examples of loads include: Appliances, lights, and power tools.
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Portable generators that are the subject of the proposed standard
commonly are purchased by household consumers to provide electrical
power during emergencies (e.g., power outages caused by storms), during
other times when electrical power to the home has been shut off, when
power is needed at locations around the home without access to
electricity, and for recreational activities (e.g., camping or
recreational vehicle trips). Built-in wheels or optional wheel kits are
often available for heavier, more powerful units (e.g., units with 3 kW
power ratings and more).
One of the primary features of a generator is the amount of
electrical power the generator can provide on a continuous basis. This
power, commonly referred to in the industry as ``rated power,'' is
advertised in units of watts or kilowatts (kW), and can range anywhere
from under 1 kW for the smallest portable generators, to nominally 15
kW for the largest portable generators.\4\ Knowing the generator's
rated power is useful in choosing the appropriate size generator for a
particular electrical load, such as providing power to power tools,
household appliances, or recreational equipment.
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\4\ As we will discuss further herein, the generator's rated
power is generally a function of the size of the engine. However,
there is no industry standard for relating the generator's rated
power to the size of the engine; nor is there any uniform way in
which electrical output capacity is advertised as ``rated.''
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IV. Risk of Injury
A. Description of Hazard
Carbon monoxide is a colorless, odorless, poisonous gas formed
during incomplete combustion of fossil fuels, such as the fuels used in
engines that power portable generators. The initial effects of CO
poisoning result primarily from oxygen deprivation (hypoxia) due to
compromised uptake, transport, and delivery of oxygen to cells. Carbon
monoxide has a 250-fold higher affinity for hemoglobin than does
oxygen. Thus, inhaled CO rapidly enters the bloodstream and effectively
displaces oxygen from red blood cells, resulting in the formation of
carboxyhemoglobin (COHb).\5\ The heart, brain, and exercising muscle
are the tissues with the highest oxygen requirements; consequently,
they are most sensitive to CO-induced hypoxia. The CO-induced hypoxia
is reflected in the non-specific, flu-like symptoms of mild CO
poisoning and early symptoms of severe poisoning, e.g., headache,
lightheadedness, nausea, and fatigue. More severe CO poisoning can
result in progressively worsening symptoms of vomiting, confusion, loss
of consciousness, coma, and ultimately, death. The high CO emission
rate of current portable generators can result in situations where the
COHb levels of exposed individuals rise suddenly and steeply, causing
people to experience rapid onset of confusion, loss of muscular
coordination, and loss of consciousness. This can occur without people
first experiencing milder CO poisoning symptoms associated with a low,
or slowly rising, CO level.
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\5\ COHb, expressed as a percentage, reflects the percentage
share of the body's total hemoglobin pool occupied by CO. Although
the relationship is not absolute, percent COHb levels can provide a
useful index of CO poisoning severity. It is measured with a blood
sample from the exposed person.
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B. Incident Data
1. Portable Generator Carbon Monoxide Fatalities
The Commission publishes an annual report that summarizes CO
incidents associated with engine-driven generators and other engine-
driven tools.\6\ The Commission is using this report to provide the
base number of incidents for the rulemaking. CPSC staff set a date of
May 21, 2015, as a cut-off for the incident data used in the briefing
package. As of May 21, 2015, CPSC databases contained reports of at
least 751 generator-related consumer CO poisoning deaths resulting from
562 incidents that occurred from 2004 through 2014.\7\ Due to incident
reporting delays, statistics for the two most recent years, 2013 and
2014, are incomplete because data collection is ongoing. Therefore, the
numbers for these years will likely increase.\8\ Figure 1 shows the
count of deaths involving a generator derived from CPSC databases for
each of these years. Note that reporting of generator-related deaths is
not a statistical sample or a complete count of incidents.
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\6\ These numbers are taken from a June 2015 reported by the
CPSC, Hnatov, Matthew, Incidents, Deaths, and In-Depth
Investigations Associated with Non-Fire Carbon Monoxide from Engine-
Driven Generators and Other Engine-Driven Tools, 2004-2014, U.S.
Consumer Product Safety Commission, Bethesda, MD, June 2015. (Docket
Identification CPSC-2006-0057-0026, available online at:
www.regulations.gov).
\7\ Id.
\8\ Note that the epidemiological benefits analysis and
preliminary regulatory analysis, discussed in Sections IV and X, do
not include the 85 deaths reported to CPSC as of May 21, 2015, for
the years 2013 and 2014 because reporting for these years is
considered incomplete. The epidemiological benefits analysis and
preliminary regulatory analysis also exclude incidents involving
generators that are out of the scope of the proposed rule (7 deaths
in 5 incidents). Therefore, the Commission's epidemiological and
regulatory analyses are based on 659 deaths in 493 incidents that
occurred from 2004 through 2012.
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2. Portable Generator Carbon Monoxide Injuries
Based on CPSC's National Electronic Injury Surveillance System
(NEISS) database,\9\ CPSC estimates that for the 9-year period of 2004
through 2012, there were 8,703 CO injuries associated with generators
seen in emergency departments (ED). This estimate should not be
considered definitive because physicians have noted difficulty in
correctly diagnosing these injuries. Carbon monoxide poisoning may
mimic many nonfatal conditions, including alcohol or drug intoxication,
psychiatric disorders, flulike illnesses, and other conditions that can
lead to misdiagnosis. Measurement of COHb levels in the victim's blood,
which could confirm CO poisoning, can also be confounded based on the
time elapsed and any supplemental oxygen treatment administered, which
can lower COHb counts prior to measurement. In addition, in some
incidents, first responders transported severely poisoned victims found
at the scene directly to a medical facility with a hyperbaric oxygen
(HBO) chamber \10\ for treatment rather than to a hospital ED. These
incidents would not have been captured in NEISS. For these reasons, the
Commission believes that the injury estimate for this proposed rule may
be low.
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\9\ The NEISS database is a national probability sample of
hospitals in the United States and its territories. Patient
information is collected from each NEISS hospital for every
emergency visit involving an injury associated with consumer
products. From this sample, the total number of product-related
injuries treated in hospital emergency rooms nationwide can be
estimated.
\10\ An HBO chamber is a facility used for exposing patients to
100 percent oxygen under supra-atmospheric conditions, to shorten
the time it would otherwise normally take for the CO to leave the
bloodstream and to increase the amount of oxygen dissolved in the
blood. A broad set of recommendations has been established for HBO
treatment for CO poisoning, which includes a COHb level above 25
percent, loss of consciousness, severe metabolic acidosis, victims
with symptoms such as persistent chest pain or altered mental
status, and pregnant women. Treatment is not recommended for mild-
to-moderate CO poisoning victims, other than those at risk for
adverse outcomes.
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In addition to using the NEISS database to estimate CO poisoning
injuries for the years 2004 through 2012, the Commission examined the
narratives of the 292 records of CO-related ED visits to NEISS-member
hospitals associated with generators for the years 2004 through 2014.
The narratives helped illustrate the range of treatments received, the
symptoms, and the reasons why victims went to a hospital ED.\11\
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\11\ Hnatov, Matthew, Summary of NEISS Records Associated with
Carbon Monoxide Exposure Cases Related to Engine-Driven Generators
in 2004 through 2014, U.S. Consumer Product Safety Commission,
Bethesda, MD, November 2015. (Docket Identification CPSC-2006-0057-
0028, available online at: www.regulations.gov).
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The Commission used the Injury Cost Model (ICM) to estimate the
number of injuries treated in locations other than hospital EDs. The
ICM uses empirical relationships between the characteristics of
injuries and victims in cases initially treated in hospital EDs and
those initially treated in other medical settings (e.g., physicians'
offices, ambulatory care centers, emergency medical clinics), based
primarily on data from the Medical Expenditure Panel Survey,\12\ to
estimate the number of medically attended
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injuries treated outside of hospital EDs. The ICM also analyzes data
from the Nationwide Inpatient Sample of the Healthcare Cost and
Utilization Project \13\ to project the number of direct hospital
admissions bypassing the hospital EDs. According to the ICM estimates,
there were an additional 16,660 medically attended CO injuries
involving generators during 2004-2012. Consequently, based on NEISS and
ICM estimates, there was a minimum of about 25,400 medically attended
CO injuries treated during the 9-year period. This is a ratio of almost
39 generator-related CO injuries to every CO death that occurred in
that period.
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\12\ The Medical Expenditure Panel Survey (MEPS) is a nationally
representative survey of the civilian non-institutionalized
population that quantifies individuals' use of health services and
corresponding medical expenditures. The MEPS is administered by the
Agency for Healthcare Research and Quality (U.S. Department of
Health & Human Services). The MEPS has been collected continuously
since 1999 and is the principal data set used to monitor medical
spending in the United States.
\13\ The National (Nationwide) Inpatient Sample (NIS) is part of
a family of databases and software tools developed for the
Healthcare Cost and Utilization Project (HCUP). The NIS is the
largest publicly available all-payer inpatient health care database
in the United States, yielding national estimates of hospital
inpatient stays. HCUP is a family of health care databases and
related software tools and products developed through a federal-
state-industry partnership and sponsored by the Agency for
Healthcare Research and Quality (U.S. Department of Health & Human
Services).
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Table 1 presents a list of the most commonly identified symptoms
given in the NEISS case narratives of 292 cases involving generator-
related CO injuries that occurred in the 11-year period from 2004
through 2014. In many cases, multiple symptoms were reported, but in 29
percent of the cases (85 of 292), symptoms were not described in the
NEISS narrative, although the diagnosis was reported. The weighted
proportion of the total appears to account for the selection
probabilities of each case.
Table 1--Most Common Symptoms Reported in NEISS CO Poisoning or CO
Exposure Cases Involving Generators, 2004-2014
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Weighted
Common symptoms * Cases proportion
(%)
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Headache.......................................... 73 27
Nausea, Felt Sick................................. 77 30
Dizzy/Confused, Disorientation, Lightheaded....... 70 25
Vomiting.......................................... 34 16
Passed Out, Unconscious, Unresponsive............. 18 5
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* Cases may appear multiple times in Table 1 because victims may have
exhibited multiple symptoms.
Table 2 presents a summary of the reasons why the patients said
they went to the emergency room for treatment or to be checked out. In
the majority of cases, the medical records, from which the narratives
were abstracted, provided little or no information on how the patients
knew they needed to go to the emergency room or how they got there.
However, in 47 of the 93 cases in which this information was available,
the patient realized something was wrong and arranged to get to the
emergency room.
Table 2--Reason Victim Went to ED for NEISS CO Poisoning or CO Exposure
Cases Involving Generators, 2004-2014
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Weighted
Reason Cases proportion (%)
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Victim realized something was wrong and 47 23
arranged to get to ER..................
Discovered in distress by family, 24 6
friend, or due to a welfare check......
Carbon monoxide alarm sounded, arranged 22 9
to get to ER...........................
Unknown why or how taken to Emergency 199 62
Room...................................
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Total............................... 292 100
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Table 3 presents a summary of the location of the generator
involved with the CO poisoning event. The three most common locations
identified were ``Inside the home'' (33%); ``Inside the garage'' (25%);
and ``In the basement'' (18%). In 11 percent of the reported cases, the
generator was located outside. In half of the ``Outside the home''
scenarios, the narrative specifically states the location was near a
window, door, or air conditioner.
Table 3--Location of Generator in Cases Reported in NEISS CO Poisoning
or CO Exposure Cases Associated With Generators, 2004-2014
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Weighted
Generator location Cases proportion *
(%)
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Inside the home................................... 86 33
Inside the garage................................. 70 25
In the basement................................... 56 18
Outside the home.................................. 29 11
Other/Unknown..................................... 51 14
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Total........................................... 292 100
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* Percentages do not sum to 100% due to rounding.
The high number of estimated injuries relative to fatalities
suggests that many more people leave the scene of the generator, are
rescued, or seek care than fatally succumb to CO poisoning. As detailed
in subsequent sections, reduced CO emissions will greatly extend the
time it takes for CO exposures to result in incapacitation and
subsequent death. Moreover, in some cases, reduced CO emissions will
actually prevent incapacitation and death from happening, even if an
individual does not leave the exposure location. In situations where a
generator is operated indoors, the extended window of time will allow
exposed individuals a much greater chance of terminating their CO
exposure or increase the chance of being found by others before serious
injury and/or death can occur. Exposure termination could occur for
several reasons, including the following:
Exposed individuals might leave the exposure location to
engage in everyday activities (e.g., work, school),
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without necessarily being aware of any developing CO hazard.
In some cases, exposure termination might occur without
the individual leaving the location, simply because the generator runs
out of fuel, or power is restored and the generator is shut down in
response, which allows CO levels to decay naturally without reaching
lethal exposure.
Exposed individuals might respond to a CO alarm
activation.
Exposed individuals might recognize a growing health
concern and leave to seek treatment or summon help (call a friend,
relative, or 9-1-1), even if they do not necessarily recognize CO
emissions as the cause of early nonspecific adverse health effects of
CO poisoning.
Exposed individuals might be found in an impaired state by
other, lesser affected, co-exposed individuals who had been in
locations farther away from the generator.
Exposed individuals might be found by concerned outside
parties conducting welfare checks, or by outside parties simply
arriving at their home for other reasons, such as, to co-commute to
work, a social or official visit, or the return home of a co-occupant
from work or school.
The Commission notes that all the reasons specified above for
exposure termination have been reported in incidents where there are
survivors of carbureted, generator-related CO poisoning. More such
cases would be expected with reduced CO emissions, due to an overall
downward shift in expected CO poisoning severity. The Commission
recognizes that consumers cannot be relied upon to react appropriately
to any indication of a CO exposure, and that even those who recognize a
developing CO hazard, might decide to enter the area where a generator
is located in an attempt to switch it off. This behavior is known to
have resulted in lethal outcomes with carbureted generators because CO
can accumulate to levels that can cause near-immediate loss of
consciousness due to hypoxia/anoxia. However, with reduced CO
emissions, the peak CO levels attained in an unventilated area where
the generator is operated will be considerably lower than the level
that would cause near-immediate loss of consciousness. This potentially
could reduce the incidence of death among individuals who enter an
unventilated area to turn off a generator, by allowing them time to
egress the area before being overcome.
C. Hazard Characteristics
As stated in the previous section, as of May 2015, there were 562
incidents involving fatalities from portable generators reported to
CPSC, which occurred between 2004 through 2014. CPSC assigned In-Depth
Investigations (IDI) for 535 of these 562 incidents (95 percent), to
gather more detailed information about the incident and the product(s)
in use. CPSC categorized the incident data in the IDI reports according
to the location where the incident occurred:
75 percent of deaths (565 deaths, 422 incidents) occurred
in a fixed-structure home location, which includes detached and
attached houses, apartments, fixed mobile homes, and cabins used as a
permanent residence;
16 percent (117 deaths, 81 incidents) occurred at non-
fixed-home locations or temporary structures, such as trailers, horse
trailers, recreational vehicles (RV), cabins (used as a temporary
shelter), tents, campers, and boats, and vehicles in which the consumer
brought the generator on board or into the vehicle;
6 percent (48 deaths, 46 incidents) occurred in external
structures at home locations, such as sheds and detached garages;
3 percent (21 deaths, 13 incidents) occurred at unknown or
other locations.
In the same 11-year period, 42 deaths from 30 incidents \14\
occurred with the generator operating outdoors, where the exhaust
infiltrated into a nearby fixed-structure home, a non-fixed-structure
home, or temporary shelter.\15\ See Figure 2.
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\14\ These figures exclude two deaths in 2011 caused by a
stationary generator operated outdoors.
\15\ Hnatov, Matthew, Carbon Monoxide Deaths Associated with
Engine-Driven Generators Located Outdoors in 2004 through 2014, U.S.
Consumer Product Safety Commission, Bethesda, MD, November 2015.
(Docket Identification CPSC-2006-0057-0028, available online at
www.regulations.gov).
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[GRAPHIC] [TIFF OMITTED] TP21NO16.004
Of the 565 deaths (422 incidents) that occurred at a fixed
structure home:
45 percent (256 deaths, 191 incidents) occurred when the
generator was operated in the living space \16\ of the house;
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\16\ Used here, living space includes all rooms, closets,
doorways and unidentified areas inside a home, but does not include
basements, which are treated as a separate category.
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25 percent (140 deaths, 108 incidents) occurred when the
generator was in the attached garage or enclosed carport;
25 percent (139 deaths, 98 incidents) occurred when the
generator was in the basement or crawlspace;
3 percent (16 deaths, 12 incidents) occurred when the
generator was operated outside; \17\
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\17\ Another 28 deaths from 19 incidents occurred with
generators operating outside structures other than fixed-structure
home sites, such as RV, camper or trailer, vehicle, boat, or cabin
used other than as a permanent residence.
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2 percent occurred when the generator was at the fixed-
structure home site, but exact location was unknown.
See Figure 3.
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[GRAPHIC] [TIFF OMITTED] TP21NO16.005
The reason the generator was needed was identified in more than 80
percent of the 562 incidents. Following are the three biggest causes:
27 percent (152 incidents) were associated with the use of
generators during a temporary power outage stemming from a weather
problem or a problem with power distribution;
21 percent of the fatal incidents (116 incidents) were
associated with the use of generators after a power shutoff by the
utility company for nonpayment of a bill, a bill dispute, or other
reason.
19 percent of the fatal incidents (109 incidents) did not
indicate why the generator was in use, or why there was no electricity
at the location of the incident.
Of the 152 fatal incidents associated with a power outage due to
weather or a problem with power distribution, 93 percent were due to
specific weather conditions. Ice or snow storms are associated with the
largest percentage of weather-related CO fatal incidents, accounting
for nearly half (49%) of the power outage-related incidents. Hurricanes
and tropical storms were associated with 28 percent of CO fatal
incidents. More than half (31 of 61) of the generator-related CO
fatalities that were hurricane- or tropical storm-related (20 of 42
fatal incidents) occurred in 2005, a year of above-average hurricane
activity.
The size of the generator involved in a CO fatality was identified
in 45 percent of the 562 incidents. Because most of the generators that
were associated with fatal CO poisoning were gasoline-fueled,\18\ staff
categorized the size of the generator by using the U.S. Environmental
Protection Agency's (EPA) classification of the small SI engine
powering it: A handheld engine \19\; a non-handheld, Class I engine; or
a non-handheld, Class II engine.\20\ The incidents involving generators
powered by non-handheld, Class II engines were then divided by whether
the engine had a single cylinder or twin cylinders.\21\ In the majority
of cases (55%), CPSC staff was unable to obtain sufficient information
to be able to categorize the generator into one of these
classifications. In the incidents where engine classification could be
determined, slightly more than one-third (35 percent) involved Class I
engine powered generators, and slightly less than two-thirds (63
percent) involved single-cylinder, Class II
[[Page 83563]]
engine-powered generators. See Figure 4. There were two incidents
involving generators powered by handheld engines that caused one death
in each incident. There were three incidents involving generators
powered by twin-cylinder, Class II engines that caused seven deaths.
Two of the incidents were single-death incidents, and the third
incident, with the generator operating outside an RV, caused five
deaths inside the RV.
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\18\ In 52 of the 562 incidents, the fuel type could not be
ascertained. Of the 510 cases where the fuel type used in the
generator was known, 99 percent (506 of 510) were gasoline-fueled
generators. Of the remaining incidents, three involved propane-
fueled generators, and the other incident involved a diesel-fueled
generator.
\19\ Although handheld engines generally are used in equipment
that is held or supported by an operator during use (such as
trimmers), handheld engines may also be used to power non-handheld
equipment, such as smaller portable generators.
\20\ The EPA broadly categorizes small SI engines as either non-
handheld or handheld, and within each of those categories, further
distinguishes them into different classes, which are based upon
engine displacement. Non-handheld engines are divided into Class I
and Class II, with Class I engines having displacement above 80 cc
up to 225 cc, and Class II engines having displacement at or above
225 cc, but with maximum power of 19 kilowatts (kW). Handheld
engines, which are divided into Classes III, IV, and V, are all at
or below 80 cc.
\21\ When the IDI did not report the generator's engine
displacement, or it was not obtainable from other information in the
IDI, staff considered the power rating of the generator, if the IDI
contained information regarding the power rating of the generator.
Staff classified generators with a reported wattage of 3.5 kW and
larger as powered by a Class II engine and those less than 3.5 kW as
powered by either a handheld or a Class I engine. To distinguish the
handheld powered generators from the Class I powered generators when
there was no information to ascertain the engine displacement,
generators with wattage of 2 kW to 3.5 kW were considered to have a
Class I engine. To distinguish the single-cylinder Class II engines
from the twin-cylinder Class II engines, staff determined from a
search of EPA's exhaust emission certification database
(www3.epa.gov/otaq/certdata.htm#smallsi) that twin-cylinder, class
II engines generally have a maximum engine power of nominally 12 kW
and higher. Based on manufacturers' generator specifications
available online, generators with engines with power equal to or
greater 12 kW, typically have a rated power of 9kW and higher.
Therefore, staff considered generators with rated power of 3.5 kW up
to 9 kW to be powered by a single-cylinder, Class II engine, and
those 9 kW and greater to be powered by a twin-cylinder, Class II
engine when there was no information to ascertain the engine
displacement and number of cylinders.
[GRAPHIC] [TIFF OMITTED] TP21NO16.006
V. Overview of Proposed Requirements
The proposed standard would apply to portable generators powered by
small handheld and non-handheld SI engines. The Commission categorized
the size of the generator using the EPA's classification of the small
SI engine powering it: A handheld engine, a non-handheld Class I
engine, or a non-handheld Class II engine. The Commission further
categorized the generators powered by non-handheld Class II engines by
whether the engine had a single cylinder or twin cylinders. The
Commission defines the generator categories (as distinguished from the
engine categories) as follows:
A handheld generator is a generator powered by an SI
engine with displacement of 80 cc or less;
A class 1 generator is a generator powered by an SI engine
with displacement greater than 80 cc but less than 225 cc;
A class 2 single cylinder generator is a generator powered
by an SI engine with one cylinder having displacement of 225 cc or
greater, up to a maximum engine power of 25 kW; and
A class 2 twin cylinder generator is a generator powered
by an SI engine with two cylinders having a total displacement of 225
cc or greater, up to a maximum engine power of 25 kW.
Although the Commission categorized generators based on the EPA
classification of the engines powering them, it is important to
distinguish these engines from the portable generators that they are
used in because the engines are also used in other products. To provide
a clear distinction, the Commission refers to engines according to
EPA's classification: Handheld engines, non-handheld Class I engines,
and non-handheld Class II engines, while referring to portable
generators according to the Commission's definitions, handheld
generators, class 1 generators, class 2 single-cylinder generators and
class 2 twin-cylinder generators.
Generators within the scope of the proposed rule provide receptacle
outlets for AC output circuits and are intended to be moved, although
not necessarily with wheels. Products that would not be covered by the
proposed rule include permanently installed stationary generators, 50
hertz generators, marine generators, generators permanently installed
in recreational vehicles, generators intended to be pulled by vehicles,
generators intended to be mounted in truck beds, and generators that
are part of welding machines. Generators powered by compression-
ignition (CI) engines (engines fueled by diesel) are also excluded from
the scope of the proposed rule. These inclusions and exclusions are
largely consistent with the scope of the two U.S. voluntary standards
for portable generators, UL 2201--Safety Standard for Portable
Generator Assemblies and PGMA G300--Safety and Performance of Portable
Generators.
The great majority of the units that fall within the scope of the
proposed standard are gasoline-fueled, but portable generators powered
by engines fueled by liquid propane (LP) present similar risks of CO
poisoning, and these units also would be covered by the proposed rule.
Some portable generators can operate fueled by gasoline, LP and natural
gas, and these would also be covered by the scope of the proposed rule.
The proposed rule specifies different limits on weighted carbon
monoxide emission rates for different classes of generators in
recognition of the effects
[[Page 83564]]
of factors such as engine size and other engine characteristics on CO
emissions, generator size, weight, and hazard patterns and the
different challenges that may be faced in meeting CO emission rates
expressed in grams per hour. The performance requirements for the
different classes of generators also have a scaling factor of 1.5
applied to the technically feasible rates to account for production
variation. Specifically, the proposed rule would require that handheld
generators and class 1 generators not exceed a weighted CO rate of 75
grams per hour (g/hr); class 2 single-cylinder generators not exceed a
weighted CO emission rate of 150 g/hr; and class 2 twin-cylinder
generators not exceed a weighted CO emission rate of 300 g/h. The
weighted emission rates are based on weighting of six modes of
generator operation, ranging from maximum generator load capability
(mode 1) to no load (mode 6), similar to a procedure used by EPA to
certify compliance with its emission standards for small SI engines.
More detail about this procedure can be found in CPSC's staff briefing
package. The performance requirements apply when generators operate at
normal oxygen content; however, the Commission remains interested in CO
emissions when generators operate at reduced oxygen content of 17
percent. The Commission welcomes comments on the advantages and
disadvantages of setting performance requirements at 17 percent oxygen
instead of normal oxygen as well as comments on the technically
feasible CO emission rates for generators operating at 17 percent
oxygen, for each of the generator categories. Furthermore, the
Commission welcomes comments on the test methods for CO emissions in
both normal oxygen and 17 percent oxygen in Tab J, Appendices A2 and A3
of the staff's briefing package.
The proposed rule does not dictate how generators would meet the CO
emission limits. Rather, under the proposed rule, firms have the
flexibility to determine the appropriate technology to meet the
specified performance requirements. To determine feasibility and to
estimate likely costs of the proposed rule, staff's briefing package,
and this preamble, discuss ways that staff believes companies might
modify generators to meet the CO emission limits. However, companies
could use other approaches.
The proposed rule describes the test procedure and equipment that
the Commission would use to assess compliance with the standard.
Manufacturers, however, need not use this particular test, so long as
the test they use effectively assesses compliance with the standard.
The Commission believes this approach provides added flexibility to
manufacturers to reduce testing burdens. The Commission welcomes
comments on the benefits and costs of this approach versus requiring a
specifc test method for manufacturers to demonstrate compliance.
In accordance with Section 9 of CPSA, the proposed rule contains a
provision that prohibits a manufacturer from ``stockpiling,'' or
substantially increasing the manufacture or importation of noncomplying
generators between the date that the proposed rule may be promulgated
as a final rule, and the final rule's effective date. The rule would
prohibit the manufacture or importation of noncomplying portable
generators by engine class in any period of 12 consecutive months
between the date of promulgation of the final rule and the effective
date, at a rate that is greater than 125% of the rate at which they
manufactured or imported portable generators with engines of the same
class during the base period for the manufacturer. The base period is
any period of 365 consecutive days, chosen by the manufacturer or
importer, in the 5-year period immediately preceding promulgation of
the rule.
Generator sales can vary substantially from year to year, depending
upon factors such as widespread power outages caused by hurricanes and
winter storms. Annual unit shipment and import data obtained by CPSC
staff show that it has not been uncommon for shipments to have varied
by 40 percent or more from year to year at least once in recent years.
The anti-stockpiling provision is intended to allow manufacturers and
importers sufficient flexibility to meet normal changes in demand that
may occur in the period between promulgation of a rule and its
effective date, while limiting their ability to stockpile noncomplying
generators for sale after the effective date. The Commission seeks
comments on the proposed product manufacture or import limits and the
base period for the stockpiling provision.
VI. CPSC Technical Analysis and Basis for Proposed Requirements
A. CPSC's Two-Part Prototype Low CO Emission Generator Technology
Demonstration Program
CPSC staff developed a two-part technology demonstration program to
demonstrate that the small SI engine powering a commercially available
portable generator could be modified with existing emission control
technology to reduce its CO emission rate to levels expected to reduce
the risk of fatal and severe CO poisoning. The objective of the first
part of the program was to develop, from a current carbureted engine-
driven generator, a prototype with a CO emission rate reduced to the
lowest technically feasible level: (1) Without negatively impacting the
engine's power output, durability, maintainability, fuel economy, and
risk of fire and burn; and (2) while also ensuring that the engine
continued to meet EPA's small SI engine exhaust emission standard for
hydrocarbons and oxides of nitrogen (HC+NOX), to which the
unmodified OEM version of the engine was originally labeled as being
certified. For this, CPSC staff sought a target CO emission rate
reduction of 90 percent. The objective of the second part of the
program was to assess the efficacy of the prototype generator in
reducing occupant exposure profiles created by its operation in a fatal
scenario commonly reported in CPSC's incident data compared to the
exposure profiles created by the unmodified carbureted generator.\22\
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\22\ Complete documentation on the prototype generator and both
parts of the demonstration program is provided in Buyer, Janet,
Technology Demonstration of a Prototype Low Carbon Monoxide Emission
Portable Generator, September 2012. (available online at: http://www.cpsc.gov/PageFiles/129846/portgen.pdf and in www.regulations.gov
in docket identification CPSC-2006-0057-0002).
---------------------------------------------------------------------------
Part One: Prototype Development and Durability Testing at University of
Alabama
The Commission contracted with the University of Alabama (UA) to
conduct the prototype development and durability phase of the program.
The prototype development started with a commercially available
generator with an advertised continuous electrical power output rating
of 5.0 kW that was powered by a small, air-cooled, single-cylinder non-
handheld Class II carbureted engine with a 389 cubic centimeter (cc)
displacement and overhead valve (OHV) configuration. The prototype was
a modification of that engine. To develop the prototype, UA replaced
the engine's carburetor with a closed-loop electronic fuel-injection
(EFI) system, used an oxygen sensor in the exhaust for closed-loop
fuel-control feedback, tuned the fuel control to stoichiometry \23\ and
replaced the muffler with a muffler that had a small three-way catalyst
(TWC) integrated into it. UA subjected the
[[Page 83565]]
prototype generator to a durability program for a total of 500 hours,
which was the manufacturer's rated useful life of the engine at the
time of the program. Simultaneous to the durability program on the
prototype generator, UA subjected a baseline unmodified carbureted
generator, the identical model to the prototype generator before
modification, to the same durability program. UA made periodic emission
measurements on both the prototype and the unmodified carbureted
generator during the 500 hours of operation to compare the performance
of the prototype to the baseline unmodified carbureted generator. After
the 500-hour durability program concluded on both the baseline
carbureted generator and the prototype generator, an independent
laboratory, Intertek Carnot Emission Services (CES), conducted end-of-
life emission testing, both with the engine installed in the generator
as well as on a dynamometer,\24\ in accordance with the EPA small SI
engine test procedures. The purpose of this testing was to ascertain
whether, at the end of the engine's rated useful life, the prototype
engine's emissions would meet: (1) The EPA's Phase 2 requirements for
HC+NOX, and (2) CPSC staff's target reduction for the
exhaust CO emission rate.
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\23\ Stoichiometry is the theoretical air-fuel ratio (AFR) for
complete combustion and is the theoretical point for nearly the
lowest amount of CO production. AFR associated with stoichiometry
for typical gasoline formulations is nominally 14.6.
\24\ A dynamometer is an instrument that measures the power
output of an engine.
---------------------------------------------------------------------------
CES's testing in accordance with EPA test procedures showed that
the prototype engine, while mounted on a dynamometer and equipped with
the muffler that had a catalyst installed, had a 6.0 g/kW-hr CO
emission rate. This CO emission rate is 99 percent below the EPA's
Phase 2 and Phase 3 CO standard of 610 g/kW-hr.\25\ The prototype
engine had an HC+NOX exhaust emission rate of 6.7 g/kW-hr.
This rate is 45 percent below the EPA's Phase 2 HC+NOX
standard for a Class II engine, to which the engine was originally
certified, and 16 percent below the Phase 3 HC+NOX standard
that came into effect shortly after CPSC's development program with UA
began. CES's dynamometer testing also showed that the prototype engine
delivered a maximum power of 7.9 kW, which is within 0.3 kW of the
advertised rated power for the unmodified OEM carbureted engine. CES's
emission testing of the prototype generator (with the engine still
installed in the generator, as opposed to mounted on the dynamometer)
measured a weighted CO emission rate of 26.10 g/hr.\26\ Thus, at the
end of the engine's rated useful life, the prototype engine's emissions
met both EPA's Phase 2 requirements for HC+NOX and CPSC
staff's target reduction for the exhaust CO emission rate. Staff's
prototype findings have since been repeated by others who patterned
their reduced CO emissions prototype generators on the design concept
developed for CPSC by the University of Alabama.\27\ Moreover, new
generator products with reduced CO emissions, achieved by similar
engine design modifications and use of catalysts, are beginning to
enter the retail market.\28\
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\25\ The EPA sets emission standards for all small SI engines.
These engines provide power for a wide range of products typically
owned by consumers, including portable generators. The EPA's primary
emphasis is on regulating emissions that contribute significantly to
nonattainment of the National Ambient Air Quality Standards (NAAQS)
for ozone, of which hydrocarbons and oxides of nitrogen
(HC+NOX) are precursors. For non-handheld engines, the
EPA adopted emission standards referred to as Phase1 in 1995, Phase
2 in 1999, and Phase 3 in 2008.
\26\ The highest of three tests was 26.10 g/hr. The other two
tests yielded weighted CO rates of 23.47 and 19.38 g/hr.
\27\ See Techtronic Industries (TTi) presentation on 3/17/16, at
PGMA's Technical Summit on Carbon Monoxide Hazard Mitigation for
Portable Generators--pages 85-105 of 178 page pdf file at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
\28\ See Tab I staff's briefing package.
---------------------------------------------------------------------------
Part Two: Comparative Testing of Unmodified Carbureted (Baseline) and
Prototype Generators at National Institute for Standards and Technology
The Commission entered into an interagency agreement with NIST to
conduct the second part of the program. In this part of the
demonstration program, NIST operated one generator in its unmodified
carbureted configuration and another generator in the prototype
configuration in the attached garage of a test house on NIST's campus.
The test house is used for conducting indoor air quality (IAQ) studies.
NIST measured the CO accumulation in the garage and transport into the
house. The results provide a sense of how quickly a commonly fatal
consumer scenario develops with an existing carbureted generator, and
what the comparative results are from the same tests with the fuel-
injected catalyzed prototype.\29\
---------------------------------------------------------------------------
\29\ Another objective of the IAG was to determine each
generator's mass CO emission rates at each of the six loads used in
the load profile. This work also supported NIST's validation of
NIST's multizone airflow and contaminant transport model CONTAM,
which is used to predict contaminant concentrations throughout a
modeled structure resulting from a source mass emission rate located
somewhere within the structure. NIST used CONTAM in predicting the
health effects of the CO rates associated with the proposed
performance requirements.
---------------------------------------------------------------------------
NIST compared the garage CO concentrations from the prototype and
the unmodified carbureted generator, after equal periods of generator
run-time in the tests, with the garage bay door fully closed. NIST
found that the prototype showed 97 percent reduction in the amount of
CO released into the garage, compared to the unmodified carbureted
generator. This reduction is consistent with UA's findings and
translated to much lower levels of CO transporting throughout the
house. Taking into consideration the CO time course profile (which is
the CO concentration over time) of each room of the house and of the
garage, the Commission performed health effects modeling and estimated
that the prototype generator resulted in a significantly extended time
interval for hypothetical occupants to escape or to be rescued before
being incapacitated. For example, in one test in which the garage bay
door and connecting door to the house were both closed, the time
interval increased by a factor of 12 with the prototype, compared to
the unmodified carbureted generator (from 8 minutes to 96 minutes) for
the deadly scenario of a consumer in the garage with the generator. The
time interval increased even more for occupants inside the house.
The Commission believes that this increased time interval could
give occupants an opportunity to remove themselves from the exposure
before being incapacitated (perhaps due to their symptoms or other
reasons such as an unrelated need to leave the house) or to be found
alive by others. In contrast, the Commission predicts that the high CO
emission rate of the unmodified carbureted generator would cause some
of the occupants, depending on where they are located, to experience
relatively quick onset of confusion, loss of muscular coordination,
loss of consciousness, and death, without having first experienced
milder CO poisoning symptoms associated with low or slowly rising CO-
induced hypoxia.
B. Staff Assessment of Feasible CO Rates Based Upon EPA's Technology
Demonstration Program and Staff Testing of Fuel-Injected Generators
A technology demonstration conducted by EPA further demonstrates
the feasibility of significantly lowering CO emission generators using
EFI.\30\ In
[[Page 83566]]
2006, EPA examined the feasibility of reducing HC+NOX
emissions beyond their Phase 2 standards.\31\ EPA applied EFI and high-
efficiency catalysts on two single-cylinder, air-cooled engines, both
nominally 500 cubic centimeters (cc) in displacement with overhead
valve (OHV) configurations. Because CO and NOX emissions
have an inverse relationship, in focusing on reducing HC+NOX
emissions, EPA specifically chose to test with catalysts formulations
designed to minimize CO oxidation.\32\
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\30\ McDonald, Joseph, Olson B, and Murawski M, Demonstration of
Advanced Emission Controls for Nonroad SI Class II Engines, SAE
paper 2009-01-1899; McDonald, Joseph, Memorandum, Re: Supplemental
Engine Dynamometer Data, May 5, 2006. (available online in:
www.regulations.gov in docket identification EPA-HQ-OAR-2004-0008-
0372.).
\31\ U.S. EPA, Control of Emissions from Marine SI and Small SI
Engines, Vessels, and Equipment--Final Regulatory Impact Analysis,
EPA420-R-08-014, September 2008 (available online in
www.regulations.gov in docket identification EPA-HQ-OAR-2004-0008-
0929); U.S. EPA, EPA Technical Study on the Safety of Emission
Controls for Nonroad Spark-Ignition Engines <50 Horsepower, EPA420-
R-06-006, March 2006, Docket Identification EPA-HQ-OAR-2004-0008-
0333. (available online at: (http://www.epa.gov/nonroad/equip-ld/phase3/420r06006-rpt-2appdx.pdf).
\32\ Oxidation of CO to carbon dioxide (CO2) is the
means by which CO emissions are reduced in a catalyst.
---------------------------------------------------------------------------
EPA used low-cost engine management and fuel injection systems that
were similar to that which UA used for the CPSC prototype generator.
While the UA generator prototype used a closed-loop system and tuned
the fuel to stoichiometry at the high loads, in interest of cost-
savings, the EPA engines did not use an oxygen sensor necessary to make
it a closed-loop fuel system. For its engines, EPA replaced the
carburetor with open-loop EFI that was calibrated rich of
stoichiometry, i.e., a lower air-to-fuel ratio, at moderate-to-high
loads and near stoichiometry at light load conditions to achieve the
desired emission control of HC+NOX. EPA developed integrated
catalyst-muffler systems for its engines, all selected to prioritize
NOX reduction and HC oxidation over CO oxidation. Even
though EPA was intentionally trying to select catalysts that would
minimize CO oxidation, both engines achieved an average 68 percent
reduction in the weighted CO emission rate. The average of the weighted
CO emission rate of the two carbureted OEM configurations was 1,760 g/
hr, and the average of the two EFI configurations with the catalyst
providing the most reduction in CO emissions was 565 g/hr.
Although the EPA noted that some engines may need improvements to
accommodate stoichiometric fuel control (such as redesign of cooling
fins, fan design, combustion chamber design, and a pressurized oil lube
system), EPA concluded that closed-loop EFI with fuel control at or
near stoichiometry is technically feasible and is not cost prohibitive
on all Class II engines.\33\
---------------------------------------------------------------------------
\33\ U.S. EPA, EPA Technical Study on the Safety of Emission
Controls for Nonroad Spark-Ignition Engines <50 Horsepower, EPA420-
R-06-006, March 2006, Docket Identification EPA-HQ-OAR-2004-0008-
0333. (available online at: (http://www.epa.gov/nonroad/equip-ld/phase3/420r06006-rpt-2appdx.pdf).
---------------------------------------------------------------------------
CPSC staff believes that with a focus on reducing CO emissions, a
lower weighted CO emission rate could have been achieved by using an
oxygen sensor for closed-loop feedback, operation closer to
stoichiometric at the higher loads, and a different catalyst formulated
for higher conversion efficiency of CO.\34\
---------------------------------------------------------------------------
\34\ See CPSC staff's briefing memorandum and Tab I of the
briefing package for a more detailed explanation.
---------------------------------------------------------------------------
CPSC staff tested three fuel-injected generators created by three
different manufacturers.\35\ Two of these generators, neither of which
was designed for low CO emissions, are available in the marketplace,
and the third is a manufacturer's prototype generator that was designed
for low CO emissions. The first of the three generators is a 10.5 kW
rated generator powered by a twin-cylinder Class II engine with nominal
700 cc displacement and overhead valve (OHV) configuration. The
generator does not have a catalyst for aftertreatment and the
generator's engine is calibrated rich of stoichiometry at higher loads
and at stoichiometry with closed-loop fuel control at moderate-to-light
load conditions. Based on CPSC staff's testing of this generator in
normal atmospheric oxygen, which found a 670 g/hr weighted CO emission
rate, as well as on staff's engineering assessment of its physical and
operational characteristics, staff believes that it is reasonable to
expect that this engine could operate closer to stoichiometric at the
higher loads and that a catalyst formulated for some CO conversion
efficiency could be used for aftertreatment to further reduce its CO
emission rate to nominally 200 g/hr.
---------------------------------------------------------------------------
\35\ See Tab I of the staff's briefing package.
---------------------------------------------------------------------------
The second generator is a 5.5 kW rated power generator powered by a
single-cylinder Class II engine with nominal 400 cc displacement and
OHV configuration, equipped with an oxygen sensor for some form of
partial closed-loop operation and a catalyst. The engine is calibrated
rich of stoichiometry at all loads. Based on staff's testing in normal
atmospheric oxygen that found a nominal weighted CO rate of 560 g/hr,
staff believes a CO emission rate of nominally 100 g/hr is possible, if
the generator were operated closer to stoichiometric for at least some
of the loads and used a catalyst formulated for higher CO conversion
efficiency.
The third generator is a 5.5 kW rated power generator powered by a
closed-loop fuel-injected single-cylinder Class II engine with nominal
400 cc displacement and OHV configuration. It has a catalyst for
aftertreatment and the engine is calibrated to stoichiometric AFR with
closed-loop operation at all loads. Staff's testing of this generator
in normal atmospheric oxygen found a weighted CO rate of 81 g/hr.
C. Assessment of Epidemiological Benefits of Reduced CO Emission
Portable Generators--NIST CO and COHb Modeling Study
1. Background
To assess the epidemiological benefits of reduced CO emission
generators, CPSC contracted NIST to perform a series of CO exposure
simulations that would model the operation of a portable generator in
various locations within various house configurations and other
structures, and at various CO emission rates.\36\ CPSC used these
results to determine the possible deaths averted if reduced CO emission
generators had been used, as described below.
---------------------------------------------------------------------------
\36\ Emmerich, Steven J., B. Polidoro, W. Dols, Simulation of
Residential CO Exposure Due to Portable Generator Operation in
Enclosed Spaces (NIST Technical Note 1925), 2016.
---------------------------------------------------------------------------
2. CO Emission Modeling
NIST modeled 40 different structures, including houses with
basements and others with crawlspaces, as well as ones with slab-on-
ground construction, with and without attached garages, and including
older construction and newer construction homes. Three different
external residential structures designed to represent detached garages
and sheds were included in the 40 structures. The 37 different house
models included detached home, attached home, and manufactured home
designs. House models and other structures used in the modeling study
were matched to 503 out of the 659 actual generator-related CO
fatalities reported to CPSC over the period 2004 to 2012. One hundred
fifty-six fatalities (659 minus 503) were not included in the modeling
analysis because the generator was either outdoors or in a structure
such as a camper, RV, tent, church, boat, or apartment complex that was
not similar to any of the structure models used by NIST. The Commission
believes that reduced emission generator use in these scenarios would
most likely have produced fewer CO fatalities than the number observed
in the incident data.
[[Page 83567]]
This would be especially true in scenarios with the generator running
outdoors, or in a large-volume space, such as a church.
CPSC staff chose the modeled CO emission rates based on: (1) CPSC's
estimates of elevated CO emission rates expected for the four
categories of current carbureted generator products when operating in a
reduced oxygen environment, and (2) a series of reduced CO generation
rates that allowed CPSC to assess benefits and costs of various levels
of reduced emissions within technically feasible rates for each
generator category.
The first part of the modeling study used the NIST multizone
airflow and contaminant transport model CONTAM, which predicted CO
levels in different areas of each structure, over a 24-hour period.
Determination of CO Emission Rates, Run Times, and Heat-Release Rates
for Carbureted Generators
Staff determined CO emission rates, run times, and heat release
rates for NIST to model for current, carbureted generators (baseline
carbureted generators) based on data from EPA's non-road small spark-
ignition engine (NRSI) certification data Web site and advertised power
ratings and engine specifications for representative products. These
baseline parameters are shown in Table 4, and an explanation of the
basis for the parameters follows.
Table 4--Modeled CO Emission Rates, Run Times, and Heat-Release Rates for Baseline Carbureted Generators
----------------------------------------------------------------------------------------------------------------
Average
weighted CO Average run Average heat
Generator category rate at 17% time (hrs) rlease rate
O2 (g/hr) (kW)
----------------------------------------------------------------------------------------------------------------
Handheld........................................................ 900 8 2
Class 1......................................................... 1,800 9 6
Class 2 Single Cylinder......................................... 4,700 10 13
Class 2 Twin Cylinder........................................... 9,100 9 25
----------------------------------------------------------------------------------------------------------------
To determine values for CO emission rates, run times, and heat-
release rates representative of current generators involved in the
fatal incidents, staff considered the generators produced by six large
generator manufacturers. All of these manufacturers are members of the
Portable Generator Manufacturers Association (PGMA), and, as documented
on PGMA's Web site, are the major manufacturers of portable generators
sold in North America and a significant majority of the industry.''
\37\ Staff used the manufacturers' reported product specifications for
31 generators ranging from 900 to 15,000 watts rated power and
developed the representative parameters for each of these inputs based
on the range of generators in each of the four categories in Table 4.
---------------------------------------------------------------------------
\37\ www.pgmaonline.com.
---------------------------------------------------------------------------
Staff used the engine specifications provided by the generator
manufacturer to search the EPA's NRSI engine certification data Web
site to find the published CO emission rate corresponding to each
generator's engine. Staff then calculated the weighted CO emission rate
(in g/hr) for each generator's engine, by multiplying the g/kW-hr rate
by 46.7 percent of the maximum engine power (46.7 percent of the
maximum engine power is the weighted average based on the EPA six-mode
calculations).\38\ Staff assumes that the typical load profile of a
portable generator used by a consumer is that of the weighted profile.
In addition, staff assumes the engine's weighted CO rate is that of the
generator.
---------------------------------------------------------------------------
\38\ The engine manufacturer's CO emission rate reported in the
EPA's exhaust emission certification Web site, in terms of grams per
kilowatt-hour (g/kW-hr), is the sum of six weighted CO rates in
grams per hour (g/hr) that the engine emits while installed on a
dynamometer test platform and operating with each of six steady-
state loads applied (also referred to as modes) divided by the sum
of the weighted power for those six modes. The EPA's six-mode test
cycle was developed with industry to replicate typical in-use
operation of small utility engines when used in all types of engine-
driven products.
---------------------------------------------------------------------------
Considering that 95 percent of the generator-related CO fatalities
in CPSC's databases occurred when the generator was operated in an
enclosed space, it is important for modeling studies to consider the CO
emission rate when a carbureted generator is operating in such enclosed
space scenarios. Evidence supporting this view is seen in results of
findings from generator tests conducted by NIST under a prior
interagency agreement with CPSC.\39\ NIST's tests, as well as
subsequent staff testing, showed that the CO emission rate of current
carbureted generators increases threefold as the oxygen drops from
normal levels (approximately 20.9 percent oxygen) to approximately 17
to 18 percent oxygen when a generator is operated in an enclosed space,
such as those reported in the incident data. Consequently, to reflect
more accurately current carbureted generator operation under oxygen
depletion conditions, staff's calculated weighted CO emission rate,
when each generator is operated outdoors at normal oxygen, was
multiplied by a factor of 3.
---------------------------------------------------------------------------
\39\ Emmerich, S.J., A. Persily, and L. Wang, Modeling and
Measuring the Effects of Portable Gasoline-Powered Generator Exhaust
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), Feb
2013.
---------------------------------------------------------------------------
The generators' run time on a full tank of gas that was associated
with 50 percent of the advertised rated load was used to determine the
full-tank run time used in the modeling. Fifty percent load was used
because, as stated above, 46.7 percent of the engine's maximum power
represents the weighted load profile, which is nominally 50 percent.
Staff generally used manufacturer's product specifications for run time
at 50 percent load, and in a few cases, used engineering estimates to
determine the run times. Staff chose to model run times based on a full
tank of fuel as a conservative assumption, despite knowledge of
scenarios where a generator was used to allow completion of a specific
short-duration task, in temporary power outage situations where power
was restored within a few hours before a full tank of fuel could be
consumed, or in scenarios where the generator was still running when
victims were found, had summoned help, and/or had removed themselves
from the area.
Staff estimated heat-release rates for these generators based on
the fuel-consumption rate at 50 percent load, the manufacturer's
specification for the generator's tank capacity, a heat of combustion
of gasoline of 42.5 MJ/kg, and an assumed conservative 35 percent
thermal efficiency of the engine.
[[Page 83568]]
Determination of CO Emission Rates, Run Times, and Heat Release Rates,
for Reduced Emission Rate Portable Generators
NIST used the same values for run times and heat-release rates for
the reduced CO emission rates of each generator category as those used
for current generators.\40\ NIST modeled the rates of 50, 125, 250,
500, 1,000 and 2,000g/hr. The three lowest of these approximates the
range of CO emission rates that staff believes are technically feasible
for both the handheld and class 1 generator categories (50 g/hr), class
2 single-cylinder category (100 g/hr), and class 2 twin-cylinder
category (200 g/hr) in ambient air with normal atmospheric oxygen.
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\40\ CPSC staff reasons that an additional weight and volume of
the emission control components needed to reduce the CO emission
rate, could be offset by a smaller fuel tank and due to the improved
fuel efficiency of reduced emission engines, the smaller tank would
still be able to maintain similar run times to carbureted units with
larger fuel tanks.
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Weather, Temperature and CO Rate Parameters for Carbureted and Reduced
CO Emission Generators
Simulations were run for each model structure and model generator
location for 28 representative weather days to determine the CO time
course profiles, which are the minute-by-minute CO concentration levels
in each of the various rooms of the house. The 28 weather days were
chosen to include 14 cold weather days (Detroit, MI), seven weather
days from warm months (Miami, FL) and seven transition months weather
days (Columbus, OH) to represent the distribution of fatalities, which
has been seen to skew towards cold-weather days in a similar
manner.\41\ Starting indoor temperatures were assumed to be 23 [deg]C
in all rooms, and temperatures were modeled to change within the rooms,
based on heat transfer related to the heat release from the generator.
Thus, generators of various sizes were modeled to be running on 28
different weather days for a full-tank run time \42\ in various rooms
within each of the structures, with run times and heat-release rates
appropriate to that size of generator, and emissions based on current
carbureted generators, or based on possible reduced-emission generators
for comparison. In the modeling of baseline carbureted generators, to
simulate the increasing CO emission rate as the oxygen level drops in
the space the generator is operating (and thus, a lower CO emission
rate at the beginning of operation than later), NIST modeled CO rates
for the first 2 hours of operation that were only two-thirds of the
rates shown in Table 4. After 2 hours, the CO rates were increased to
the rates in Table 4 for the duration of the run time. In contrast, as
another conservative assumption, NIST modeled reduced CO emission rates
as constant rates for the entire respective generator run time. The
results of the models provided CO time-course profiles for each room of
each structure on each weather day for each generator type and location
and emission rate.
---------------------------------------------------------------------------
\41\ The 28 individual days were selected using historic weather
data recorded at three different geographic locations and three
different temperature ranges to approximate the distribution of
incidents observed in the CPSC incident data at a generalized level.
Although the weather days may be consecutive (e.g., 14 consecutive
cold weather days), there was no carry-over effect from one day to
the next. Each day modeled was reset to zero CO. Therefore, each
day, from a CO standpoint, was an independent event.
\42\ NIST also modeled half-tank run times to simulate scenarios
where shorter duration were considered more appropriate (e.g., in
scenarios in which the generator was being used to allow completion
of a specific short-duration task at an unpowered location, in
temporary power outage situations, where power was restored within a
few hours before a full tank of fuel could be consumed, or in
scenarios where the generator was still running when victims were
found, had summoned help, and/or had removed themselves from the
area). While staff has these modeling results, staff only analyzed
the modeling results for the full-tank run times to estimate those
benefits so as to be consistent with a conservative estimate of
benefits.
---------------------------------------------------------------------------
3. Application of COHb Modeling
The second part of the modeling study used the CONTAM-generated CO
time course profiles as input values to predict corresponding COHb
levels expected in healthy adults, as a function of time, using Coburn
Forster Kane (CFK) modeling.\43\ Conservative assumptions were made
about respiratory rates, given expected activity rates over the 24-
hours of modeled exposure. The respiratory minute volume (RMV),
expressed in liters per minute (L/min), is the specific inhalation rate
input value used in the CFK, and for the epidemiological benefits
calculated in this analysis, staff used an RMV of 10 L/min. Staff's use
of a constant 10 L/min RMV for light activity likely overestimates the
breathing rate (and CO uptake rate) of a significant number of victims.
In the majority of fatal incidents, victims were at home during an
unplanned power outage, or an outage due to utility shut off, and there
was no indication that they had engaged in more than sedentary-to-light
activity levels for most of the time. For example, in several of these
cases, a generator was first started in an enclosed space late in the
evening/night at a time where victims were clearly preparing for/or
retired to bed; in these instances, a sedentary/resting activity level
of 6 L/min RMV would be more appropriate. Thus, use of an RMV of 10 L/
min is another conservative assumption in the analysis. This is
explained in more detail in Tab K of staff's briefing package and its
appendix.
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\43\ The CFK modeling is a nonlinear differential equation that
is a physiologically based mechanistic model for predicting CO
uptake and COHb formation and elimination in humans; it has been
validated by empirical data from human studies and is widely
regarded by authoritative sources as a reasonably reliable and
broadly applicable COHb model for acute exposures.
---------------------------------------------------------------------------
To assess the impact of low-emission generators on potential
reductions in CO fatalities, the number of observed fatalities from the
incident data were assigned to one of the model structures. The initial
step was to assign the fatalities that occurred in an ``exact match''
structure type. ``Exact match'' structures are defined as those that
match all of the NIST structure characteristic parameters used in the
analysis to describe the structure, such as floor area, number of
floors, existence of a garage and/or basement. Where exact matches
could not be assigned, fatalities were apportioned among best matching
structure types (those matching the most number of NIST parameters).
These simulations included various generator location scenarios,
dependent on house/structure model designs (i.e., only models that had
a basement included the generator-in-basement scenario; and only models
that had an attached garage included the generator-in-the-attached
garage scenario). To match, as closely as possible, actual usage
patterns, the simulation results of the generator locations within the
house/structure were proportionately equal to those observed in the
incident data.
The victim's location in the modeled house is assumed to have equal
probability of occurring in any living space room. This assumption was
made for three reasons. In multi-fatality incidents, victims were often
found in different locations within a house. In many cases, the
victim's location could not be determined from available reports.
Moreover, it was frequently unclear whether victims were located in a
single area in which they were found for the entire time or if the
individual moved around through various parts of the structure. An
example of the latter case could be that an individual felt sick and
moved, perhaps, to a bedroom to lie down before expiring.
Next, CPSC staff incorporated criteria that staff developed to
evaluate modeled COHb profiles considered indicative of
[[Page 83569]]
fatal versus nonfatal outcomes. CPSC's Health Sciences (HS) staff
developed four ``COHb Analysis Criteria'' to assess whether predicted
COHb profiles from modeled residential scenarios were likely indicative
of fatal or nonfatal CO exposures in average adults.\44\ Where a fatal
outcome is predicted, the criteria can be used to assess the predicted
time to reach fatal exposure during a 24 hour modeling period for each
simulated CO exposure. The criteria are intended to reflect the fact
that lethal CO health effects are not simply a function of acute
hypoxia resulting from a critical reduction in blood levels of oxygen
delivered to tissues, as indicated by attainment of a specific peak
COHb level.\45\ The criteria include some consideration of the level
and duration of the predicted COHb elevation, which recognizes that, in
addition to reducing oxygen delivery to tissues, CO can enter the non-
vascular body compartment and adversely impact important cellular
functions by displacing oxygen from various intracellular heme proteins
(particularly myoglobin proteins found predominantly in cardiac and
skeletal muscles, and certain cytochrome P-450 enzymes involved is
cellular respiration). In some prolonged CO elevations, the additional
nonvascular adverse effects of CO can result in death at COHb levels
that are not typically lethal.
---------------------------------------------------------------------------
\44\ See Tab K and Tab K appendices of staff's briefing
memorandum.
\45\ Oxygen binding sites of hemoglobin molecules have more than
200-fold higher affinity for CO than for oxygen.
---------------------------------------------------------------------------
Although the relationship is not absolute, physiological,
epidemiological, and clinical studies provide evidence that acute CO
poisoning effects in healthy adults tend to follow toxicological dose-
response principles, and that risk of more serious adverse CO poisoning
effects worsen progressively as blood levels of COHb increase.\46\
However, it is clear that lethal CO exposures cannot be defined simply
by attainment of a single COHb level. Staff used several information
sources to develop COHb assessment criteria to facilitate calculation
of benefits estimates predicted for generators with reduced CO
emissions. A recent authoritative review of CO toxicity by the Agency
for Toxic Substances and Disease Registry indicates that there is a
high risk of lethal outcome once COHb levels have reached a critical
window, which, for healthy individuals, is generally considered to lie
between 40 percent and 60 percent COHb.\47\ HS staff reviewed
information on COHb levels of victims who experienced acute, generator-
related CO poisoning; COHb levels documented in fatal CO poisoning
cases reported to CPSC were compared with COHb levels reported for a
select group of survivors who received hyperbaric oxygen treatment
(HBO-T) for generator-related CO poisoning injuries considered to be of
high severity. Staff also considered information on fatal and nonfatal
COHb levels reported in non-fire-related CO poisoning cases that did
not specifically involve generator-related CO exposures. Based on
review of available data on COHb levels in fatal and nonfatal
generator-related CO exposures, and other non-generator, non-fire
related CO deaths and injuries, staff developed the following criteria
to distinguish between modeled COHb levels indicative of lethal versus
nonlethal outcome:
---------------------------------------------------------------------------
\46\ For example, loss of consciousness is not generally
expected in average adults if peak COHb levels remain below 20
percent, but becomes increasingly more likely as levels approach,
and exceed, 40 percent COHb. (Note: Staff is referring to the acute
COHb blood levels actually reached, or predicted by modeling, which
is not necessarily the same as the highest measured COHb levels
reported in clinical cases, where initial COHb measurements are
typically reduced from peak levels attained, primarily due to the
time lag between the end of CO exposure and blood sampling, plus use
of supplemental oxygen during this interval).
\47\ Agency for Toxic Substances and Disease Registry (ATSDR),
(June 2012) Toxicological Profile for carbon monoxide (web link:
http://www.atsdr.cdc.gov/toxprofiles/tp201.pdf.
---------------------------------------------------------------------------
(1) If peak level is >=60% COHb, assume death.
(2) If peak level is >=50% COHb but <60%, assume death unless
average duration of elevation >50% COHb is less than 2 hours, and
average duration of elevation between >=40% and <50% COHb is less than
4 hours.
(3) If peak level is >=40% COHb, but <50% COHb, assume death if
duration of the average in this range exceeds 6 hours.
(4) If peak level is <=40% COHb, assume survival.
4. Determination of Deaths Averted
The final part of the modeling study used patterns evident in fatal
incident data (such as the known percentages of deaths related to
various generator locations for various generator sizes and structure
types) to modulate the modeled COHb data to estimate the number of
fatal CO exposures reported for each generator category that could have
been averted at each reduced emission rate. The modeling included
exposure duration of up to 24 hours, estimated on a minute-by-minute
resolution, and determined the status of living versus dead for modeled
occupants at each minute in time. The model assumed equal probabilities
of intervention over a 24-hour period. This assumption was used because
frequently, one could not determine from the incident data how long of
an interval between when the generator was started and when the victim
died or some other type of intervention occurred.
Although CPSC incident data reflect primarily fatal CO incidents,
the assumption that surviving people eventually depart the exposure is
supported by staff's estimates of at least 25,400 medically attended CO
injuries involving generators over the period of the deaths modeled and
the fact that in some fatal incidents, there were surviving victims.
For each scenario (CO emission rate, structure model, generator
location, occupied zone, weather day), the model produced estimated
COHb levels. From these COHb levels, staff determined at each minute
interval, whether the victim was dead or alive, based on the criteria
outlined above. The average per-minute interval over the 28 days
produced a probability of fatality at the given time. Under the
assumption of equal probability of intervention over the 24-hour
period, the average probability of fatality over the 24-hour period is
the overall fatality rate for the given scenario. For the current
carbureted generator model simulation, the probability was normalized
(scaled up) to 100 percent of the allocated deaths because this is
based on the actual incident data. The reduced emission rate simulation
results were scaled up by the same factor to normalize the data. The
difference between the allocated deaths per scenario and the number
estimated for the reduced emission levels is the estimate of the deaths
averted for the specified scenario. The summation of all the modeled
scenarios (at a given emission level) represents an estimate of the
potential deaths averted, if a reduced emission level generator had
been in use in place of the current carbureted types. Thus, the same
scenarios and assumptions were used for each generator size, generator
location, structure, and weather day combination for current and
reduced emissions generators so that the comparison was consistent and
the assumptions would apply in the same way to current and reduced
emissions.
Table 5 presents a summary of the number of deaths that potentially
could have been averted over the 2004 to 2012 time span, if low-
emission generators were used in place of the high CO output generators
that were in use during this period. CPSC staff estimates that a total
of 208 out of 503 deaths
[[Page 83570]]
could have been averted. CPSC staff realizes there is uncertainty
associated with this estimate given the assumptions and estimations
staff used in developing this estimate. However, CPSC staff used
conservative values and believes the uncertainty in the estimate is
within the range of the sensitivity analysis that staff performed on
the effectiveness of the emission rates, as described in the
preliminary regulatory analysis.
Table 5--Summary of Potential Deaths Averted at Technically Feasible CO Emission Rates in Reduced Oxygen, 2004-
2012
----------------------------------------------------------------------------------------------------------------
CO emission
rate *
simulating Actual Potential Potential
Generator category generator fatalities deaths lives saved
operation in allocated by averted rate (%)
an enclosed class
space
----------------------------------------------------------------------------------------------------------------
Handheld....................................... 150 3.7 1.7 46.6
Class 1........................................ 150 176.2 87.7 49.7
Class 2 Single Cylinder........................ 300 321.3 117.9 36.7
Class 2 Twin Cylinder.......................... 600 1.8 0.3 17.2
----------------------------------------------------------------
Total...................................... ............... 503.0 207.6 = ~208 41.3
----------------------------------------------------------------------------------------------------------------
* These rates are 3 times the technically feasible rates at normal ambient oxygen (~20.9%) to account for CO
emission rate increase in reduced oxygen. To account for production variation the CO emission rates in the
proposed requirements are 1.5 times the technically feasible rate in normal oxygen.
The numbers are based on the conservative assumption of CO emission
rates tripling from technically feasible rates in normal oxygen for
each generator category when operating in theorized oxygen depletion.
Staff tripled the rates because staff determined that in reduced oxygen
levels, the emission rates of generators that meet the technically
feasible rates in ambient air may increase. This factor of 3 is based
on testing of carbureted generators conducted by NIST \48\ and CPSC
staff.\49\ However, test results from NIST \50\ indicate that the EFI
generator depleted the oxygen significantly less than the carbureted
generator when tested in each matched pair identical test scenario.
Furthermore, based on staff's testing of three generators with fuel-
injected engines having different degrees of closed-loop operation,
staff believes the factor of increase when the oxygen is 17 percent may
be less than 3 for some generators that use closed-loop EFI.\51\
Therefore, based on both of these issues, the factor of 3 could likely
overstate the weighted CO emission rates for some EFI generators when
operated indoors, and understate the reduction in deaths and injuries
resulting from the proposed standard. Consequently, staff believes that
the assumption of a threefold increase in the technically feasible
rates in ambient oxygen is an appropriate assumption to model,
conservatively, for generators operating in enclosed space. Thus, staff
ultimately determined epidemiological benefits overall, based on
emission rates of 150, 300, and 600 g/hr technically feasible rates, as
shown in Table 5.
---------------------------------------------------------------------------
\48\ Emmerich SJ, Polidoro, B, Dols WS. Simulation of
Residential CO Exposure Due to Indoor Portable Generator Operation,
NIST Technical Note 1925, 2016.
\49\ See Tab J in the staff's briefing package.
\50\ Buyer J. Technology demonstration of a Prototype Low Carbon
Monoxide Emission Portable Generator. U.S. Consumer Product Safety
Commission, Bethesda, MD, September 2012.
\51\ Tab J of staff's briefing package.
---------------------------------------------------------------------------
Staff expects that some additional, but unquantified deaths, could
be averted in the remaining 24 percent of fatalities that were not
modeled, especially in fatal incidents where a generator was operated
outdoors, and/or, that had co-exposed survivors. Staff's
epidemiological benefits analysis is contained in TAB K of the staff's
briefing package.
VII. Relevant Existing Standards
A. Portable Generator Label
On January 4, 2007, the CPSC voted unanimously (2-0) to require
manufacturers of portable generators to warn consumers of carbon
monoxide (CO) hazards through a mandatory label containing performance
and technical data related to the performance and safety of portable
generators. The required warning label informs purchasers: ``Using a
generator indoors CAN KILL YOU IN MINUTES''; ``Generator exhaust
contains carbon monoxide. This is a poison you cannot see or smell'';
``NEVER use inside a home or garage, EVEN IF doors and windows are
open''; ``Only use OUTSIDE and far away from windows, doors, and
vents.'' The label also includes pictograms. The label requirement went
into effect on May 14, 2007, and is required for any portable generator
manufactured or imported after that date.\52\ Although the Commission
believes that the mandatory label for portable generators might prevent
some incidents of CO poisoning and death, as discussed in more detail
in Section VIII of this preamble, evidence suggests that labeling alone
is not sufficient to address the CO poisoning hazard, and that
performance requirements for portable generators are needed.
---------------------------------------------------------------------------
\52\ 16 CFR part 1407.
---------------------------------------------------------------------------
B. Voluntary Standards
Underwriters' Laboratories Inc. (UL) and the PGMA have each been
accredited by the American National Standards Institute (ANSI) to
develop a U.S. safety standard for portable generators. However, only
PGMA has developed an ANSI standard for portable generators, ANSI/PMGA
G300-2015. UL has also developed a standard, UL 2201, which has not
become an ANSI standard, due to lack of consensus. International
Organization for Standardization (ISO) 8528-13:2016, Reciprocating
Internal Combustion Engine Driven Alternating Current Generating Sets--
Part 13: Safety, is a standard applicable to portable generators sold
overseas.
1. UL 2201
In 2002, UL formed a standards technical panel (STP) to develop the
first voluntary standard in the United States, dedicated solely to
portable generators, UL 2201 Safety Standard for Portable Generator
Assemblies. CPSC technical staff joined the STP for UL 2201 at its
inception and has been an active participant with a long record of
[[Page 83571]]
advocating that the standard address CO poisonings.
The requirements in UL 2201 cover internal combustion engine-driven
generators rated 15 kW or less, 250 V or less, which are provided only
with receptacle outlets for the AC output circuits. The scope section
of UL 2201 states that the standard addresses: ``the electric shock,
fire, and casualty aspects associated with the mechanical performance
and the electrical features of portable engine-driven generator
assemblies.'' The standard restates the mandatory CPSC label
requirement, but the standard does not otherwise address the risks
related to CO poisoning. UL 2201 includes construction requirements to
define minimum acceptability of components of the fuel system, engine,
alternator, output wiring and devices, frame/enclosures and others, to
ensure their suitability in this application to mitigate the risk of
shock, fire and physical injury to users. The standard includes tests
applicable to electrical, fire or mechanical hazards, as well as
manufacturing tests.
UL has been unable to achieve consensus within the STP for UL 2201
to be recognized as an ANSI standard. Therefore UL 2201, first
published in 2009, currently exists as a UL standard without ANSI
recognition.
In January 2014, CPSC staff sent a letter to the UL 2201 STP Chair
to request that a task group be formed to work on proposals to address
the CO hazard that would eventually be balloted by the STP.\53\ The
letter outlined a framework of requirements based on work done by and
for CPSC staff, which could be used as a starting point for
discussions. This letter is described in more detail in the staff's
briefing package. Accordingly, UL formed a task group with a roster of
37 members representing a broad range of stakeholder interests,
including manufacturers of engines, generators, fuel-control systems
and emission control components; public health officials; first
responders; medical experts; indoor air quality experts; and government
representatives from National Institute for Occupational Safety and
Health (NIOSH), Centers for Disease Control and Prevention (CDC), NIST,
and CPSC staff. The task group chair is a representative from NIOSH.
The first meeting of the task group was held in May 2014. As of August
2016, there have been 26 meetings, all held as teleconference meetings,
and there has been active participation and constructive input from a
number of the members, but the task group has not yet sent a proposal
to the STP to consider for adoption into UL 2201. A more detailed
description of this effort is provided in TAB I of the staff's briefing
package.
---------------------------------------------------------------------------
\53\ Buyer, Janet, letter to Diana Pappas-Jordan, RE: CPSC Staff
Request for Formation of a Working Group and Staff's Recommendations
for Requirements to Address the Carbon Monoxide Poisoning Hazard
Associated with Portable Generators, January 14, 2014. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCstafflettertoULdatedJan142014.pdf.
---------------------------------------------------------------------------
The Commission is unaware of any portable generator that is, or has
been, certified to UL 2201; as such, it is unlikely that there would be
substantial compliance with the standard it if CO emissions
requirements were incorporated.
2. ANSI/PGMA G300-2015
In 2011, PGMA was accredited by ANSI to be a standards development
organization, allowing PGMA, in addition to UL, to develop a standard
for portable generators. PGMA is the accredited standards development
organization for ANSI PGMA G300--Safety and Performance of Portable
Generators. CPSC staff served on PGMA's canvass committee. CPSC staff
submitted comments to the standard, including comments regarding the
lack of requirements in the standard to address the CO hazard.\54\ PGMA
published the first edition PGMA G300 as an American National Standard
in June 2015.
---------------------------------------------------------------------------
\54\ Buyer, Janet, letter to Joseph Harding, Subj: CPSC Staff
Comments on BSR/PGMA G300-201x, Safety and Performance of Portable
Generators, January 2, 2015. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCstafflettertoPGMAregardingG300draftstandarddated122015.pdf;
Buyer, Janet, letter to Joseph Harding, Subj: CPSC Staff Comments on
BSR/PGMA G300-201x, Safety and Performance of Portable Generators
dated January 30, 2015, March 6, 2015. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSC-staff-letter-to-PGMA-with-comments-on-draft-G300-standard.pdf.
---------------------------------------------------------------------------
PGMA G300 provides a method for testing the safety and performance
of portable generators ``rated 15 kW or smaller; single phase; 300 V or
lower; 60 hertz; gasoline, liquefied petroleum gas (LPG) and diesel
engine driven portable generators intended for multiple use and
intended to be moved, though not necessarily with wheels.'' PGMA G300
includes construction requirements for engines, fuel systems, frame/
enclosures, alternators, and output wiring and devices. The standard
includes safety tests intended to address electrical, fire or
mechanical hazards during intended generator operation. It also
includes a section on testing for determination of output power rating
that it delineates as non-safety based. PGMA G300 also includes
manufacturing tests to ensure minimum levels of safety for production
units. Although the standard restates the mandatory CPSC label
requirement for portable generators, it does not otherwise address the
risks related to CO poisoning.
CPSC staff continues to work with PGMA and urge them to address the
CO hazard.\55\ CPSC staff participated in a PGMA technical summit on
March 17, 2016, and reaffirmed this commitment.\56\ In April 2016, PGMA
informed staff that ``the PGMA Technical Committee will create a
performance based standard that addresses the CO hazard created when
portable generators are misused by operating them in or near occupied
spaces as its top priority. The performance standard, once developed,
will be proposed to the canvass group for addition to ANSI/PGMA G300 in
the next revision cycle.'' \57\ CPSC staff responded to PGMA \58\ and
met with PGMA again at PGMA's request in August \59\ and September
2016.\60\
---------------------------------------------------------------------------
\55\ Letter from PGMA to Joel Recht, dated April 20, 2016,
available online at: http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Voluntary-Standards-Reports/PGMALettertoRechtCPSCCooperationFinal.pdf.
\56\ CPSC staff presentation, CPSC Staff Technical Research to
Address the Carbon Monoxide Hazard for Portable Generators, March
17, 2016.
\57\ The Commission's understanding is that PGMA's revision
cycle is every 5 years.
\58\ Recht, Joel, Letter to Susan Orenga, Response to PGMA
Letter to Joel Recht dated April 20, 2016, May 13, 2016. http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Voluntary-Standards/Portable-Generators/CPSCRechtLettertoPGMAMay132016inresponsetoPGMAletterdatedApril202016.pdf.
\59\ Smith, Timothy, Log of Meeting, CPSC Staff, PGMA, and
Exponent, August 12, 2016, available online at: https://www.cpsc.gov/s3fs-public/Meeting%20Log%20for%20meeting%20with%20PGMA%202016-08-12_0.pdf.
\60\ Recht, Joel, Log of Meeting, CPSC Staff and PGMA, September
6, 2016, available online at: https://www.cpsc.gov/s3fs-public/09%2006%2016%20Meeting%20with%20PGMA%20Follow%20up%20on%20Technical%20Summit%20on%20Carbon%20Monoxide%20Hazard%20Mitigation%20for%20Portable%20Generators.pdf.
---------------------------------------------------------------------------
On September 19, 2016, PGMA emailed a letter to Chairman Kaye
indicating that PGMA is in the process of re-opening G300 and
announcing its intent to develop a ``performance strategy focused on CO
concentrations.'' \61\ In the letter to Chairman Kaye and in CPSC
staff's September meeting with PGMA, PGMA described only broad
generalities of a framework for modifying G300 that involves testing a
generator in an
[[Page 83572]]
enclosed space (test chamber).\62\ The Commission looks forward to
working with PGMA on developing a performance requirement addressing
the CO poisoning hazard associated with portable generators. Given that
PGMA described only broad generalities to CPSC regarding PGMA's intent
to modify G300, the Commission does not have an adequate basis to
determine if modifications to the voluntary standard would likely
eliminate or reduce the risk of injury or death. In addition, because
the Commission is unaware of any portable generator that is or has been
certified to G300, it is unlikely there would be substantial compliance
if CO emissions requirements were incorporated.
---------------------------------------------------------------------------
\61\ Letter from PGMA to Chairman Elliot Kaye, dated September
16, 2016, available online at: https://www.cpsc.gov/s3fs-public/PGMALtrChairKayeVoluntaryStandardFinal.pdf.
\62\ Product Safety Letter, PGMA Talks Broad Strokes on
Standards Work with CPSC, Volume 45, Issue 34, September 12, 2016.
---------------------------------------------------------------------------
3. ISO 8528-13:2016
ISO 8528-13:2016 Reciprocating Internal Combustion Engine Driven
Alternating Current Generating Sets--Part 13: Safety, is a standard
applicable to portable generators sold overseas. Its requirements
regarding the CO poisoning hazard are limited to labels and markings.
It requires that the generating set must have a visible, legible, and
indelible label that instructs the user: ``exhaust gas is poisonous, do
not operate in an unventilated area.'' The standard also requires that
the general safety information section of the instruction manual
mention: ``Engine exhaust gases are toxic. Do not operate in
unventilated rooms. When installed in ventilated rooms, additional
requirements for fire and explosion shall be observed.''
C. Adequacy of the Voluntary Standards for Portable Generators in
Addressing CO Deaths and Injuries
The Commission does not believe that any of the standards discussed
in the previous section are adequate because they fail to address the
risk of CO hazard beyond restating the CPSC mandatory labeling
requirement and the Commission does not believe that the mandatory
labeling requirements, alone, are sufficient to address the hazard.
Additionally, the Commission is not aware of any firms certifying
products to these standards. Thus, the Commission does not believe
there is substantial compliance with the standards. Therefore, the
Commission concludes that the voluntary standards are not adequate in
addressing CO deaths and injuries.
VIII. Response to Comments
In this section, we describe and respond to comments to the ANPR
for portable generators. We present a summary of each of the
commenter's topics, followed by the Commission's response. The
Commission received 10 comments in response to the ANPR. Subsequently,
in a two-part technology demonstration, CPSC contracted with UA to
conduct a generator prototype development and durability demonstration
program and contracted with NIST to conduct comparative testing of an
unmodified carbureted generator and prototype generators in an attached
garage of a test house facility. CPSC staff published a report
regarding the results of the two-part technology demonstration program
that included both the UA development and durability program and the
NIST comparative testing program \63\ and received 12 comments in
response to this report. NIST published a report concerning its
comparative testing of generators,\64\ and staff received four comments
in response to its report. The Commission responds to these comments,
as well. The comments can be viewed on: www.regulations.gov, by
searching under the docket number of the ANPR, CPSC-2006-0057.
---------------------------------------------------------------------------
\63\ Buyer, Janet, Technology Demonstration Of A Prototype Low
Carbon Monoxide Emission Portable Generator, September 2012.
(available online at: http://www.cpsc.gov/PageFiles/129846/portgen.pdf and in www.regulations.gov in docket identification
CPSC-2006-0057-0002.).
\64\ Emmerich, S.J., A. Persily, and L. Wang, Modeling and
Measuring the Effects of Portable Gasoline Powered Generator Exhaust
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), National
Institute of Standards and Technology, Gaithersburg, MD, February
2013. (available online at: http://www.cpsc.gov/Global/Research-and-Statistics/Technical-Reports/Home/Portable-Generators/PortableGenerators041213.pdf.
---------------------------------------------------------------------------
A. Mandatory Carbon Monoxide Label
Comment: One commenter claimed that the CO hazard will continue to
exist even if the Commission's demonstrated technology of the prototype
were applied to commercially available generators and that ``educating
owners about the proper use of their generators will therefore remain
the first line of defense.'' The commenter claimed that, for this
reason, the CPSC should ``conduct a study that includes a human factors
analysis to determine the effectiveness of the CPSC mandated CO warning
adopted in 2007.'' The commenter also encouraged CPSC to revise the
mandated warning ``to incorporate the standards and format'' in ANSI
Z535.3-2011, American National Standard Criteria for Safety Symbols,
and Z535.4-2011, American National Standard Product Safety Signs and
Labels.
Response: Although the Commission concurs with the commenter that
the CO hazard associated with portable generators will continue to
exist to some degree, even if CPSC's demonstrated technology were
applied to commercially available generators, it does not necessarily
follow that educating owners about the proper use of generators is,
should be, or would remain, the first line of defense. Human factors
and safety literature identify a classic hierarchy of approaches to
control hazards, based primarily on the effectiveness of each approach
in eliminating or reducing exposure to the hazard. The use of hazard
communications such as warning labels is universally recognized as less
effective than designing-out the hazard of the product or guarding the
consumer from the hazard. Thus, hazard communications are lower in this
``hazard control hierarchy'' than these other two approaches.\65\
Hazard communications are less effective because they do not prevent
consumer exposure to the hazard; instead, they must persuade consumers,
who see and understand the communication, to alter their behavior in
some way to avoid the hazard. Thus, hazard communications should be
thought of as ``last resort'' measures that supplement, rather than
replace, product redesign or guarding efforts to address residual
risks, unless these higher level hazard-control efforts are unfeasible.
---------------------------------------------------------------------------
\65\ Laughery, K.R., & Wogalter, M.S. (2011). The Hazard Control
Hierarchy and its Utility in Safety Decisions about Consumer
Products. In W. Karwowski, M.M. Soares, & N.A. Stanton (Eds.), Human
Factors and Ergonomics in Consumer Product Design: Uses and
Applications (pp. 33-39). Boca Raton, FL: CRC Press; Vredenburgh,
A.G., & Zackowitz, I.B. (2005). Human Factors Issues to Be
Considered by Product Liability Experts. In Y.I. Noy & W. Karwowski
(Eds.), Handbook of Human Factors in Litigation (Chapter 26). Boca
Raton, FL: CRC Press; Williams, D.J., & Noyes, J.M. (2011). Reducing
the Risk to Consumers: Implications for Designing Safe Consumer
Products. In W. Karwowski, M.M. Soares, & N.A. Stanton (Eds.), Human
Factors and Ergonomics in Consumer Product Design: Uses and
Applications (pp. 3-21). Boca Raton, FL: CRC Press.
---------------------------------------------------------------------------
The commenter recommends that CPSC conduct a study to determine the
effectiveness of the CPSC-mandated CO warning. The commenter states
that testing is needed because of the importance of ``educating owners
about the proper use of their generators.'' Based on this assertion,
the Commission infers that the commenter's measure of effectiveness is
the extent to which the warning is understood by consumers, assuming
the warning had initially captured and maintained the
[[Page 83573]]
consumers' attention. CPSC's mandatory labeling requirements for
portable generators states that the product label shall be located on a
part of the generator that is ``prominent and conspicuous to the
operator,'' while performing at least two of the following operations:
Filling the fuel tank, accessing the receptacle panel, and starting the
engine.\66\ The rule also requires that the label remain permanently
affixed, intact, legible, and largely unfaded over the life of the
product.\67\ These requirements, as well as the minimum type size
requirements,\68\ were developed purposefully to address issues related
to capturing and maintaining consumer attention and should address most
concerns of this type, except for cases in which the user of the
generator is not literate in English. However, the question of whether
the label also should be provided in languages other than English was
raised and addressed in detail in the final rule.\69\ In summary: (1)
Available generator-related incident data have revealed no pattern of
incidents involving people who could not read English; (2) the overall
positive impact of adding another language to a label is likely to be
very small; and (3) the regulation does not prohibit the addition of
another language version of the warning message to the mandatory label.
---------------------------------------------------------------------------
\66\ 16 CFR 1407.3(a)(iii)(B).
\67\ 16 CFR 1407.3(a)(iv).
\68\ The signal word ``DANGER'' must be in letters not less than
0.15 inches and the remaining text must be in type whose uppercase
letters are not less than 0.10 inches, or about 10-point type size.
\69\ 72 FR 1443 (January 12, 2007).
---------------------------------------------------------------------------
The Commission supports the testing of warnings and other hazard
communications. However, as discussed in the preamble to the mandatory
labeling final rule, an independent contractor already performed focus-
group testing with low-literacy individuals on the product label
initially proposed in the notice of proposed rulemaking (NPR), and the
Commission revised the final label to address the message text
comprehension problems identified during testing.\70\ The Commission
acknowledges that incremental improvements to the language of the label
might be possible by conducting additional comprehension testing.
However, the Commission also believes that the most significant label
comprehension problems have already been addressed and that additional
testing of this sort is unlikely to detect problems that would
substantially impact comprehension among those at risk.\71\ In terms of
the formatting of the mandatory label, the Commission notes that the
formatting and requirements of the mandatory generator label are
virtually identical to the requirements of ANSI Z535.4-2011 and Z535.3-
2011. Although the Commission acknowledges that the formatting of the
mandatory label technically does not match the panel format
requirements of ANSI Z535.4, these differences were deliberate and
intended to improve warning comprehension. In addition, the Z535 series
of standards includes exceptions and examples that are consistent with
the formatting of the mandatory label. Revising the mandatory label to
strictly meet the panel format requirements of Z535.4 is unlikely to
improve the effectiveness of the label, and the Commission believes
such changes actually could have a negative impact because it would
separate the graphics from the relevant safety messages. Thus, the
Commission believes that such revisions are neither appropriate, nor
desirable.
---------------------------------------------------------------------------
\70\ Id.
\71\ Virzi, R.A. (1992). Refining the test phase of usability
evaluation: How many subjects is enough? Human Factors, 34(4), 457-
468, has found that about 80 percent of all usability problems tend
to be detected with only four or five subjects; about 95 percent of
all problems are detected with nine subjects; and each additional
subject was less likely to detect new usability problems. The
Commission believes that these general principles are likely to
apply to comprehension testing as well, particularly in tests that
oversample low-literacy individuals.
---------------------------------------------------------------------------
B. Technical Requirements/Specifications
1. Comment: Two commenters state that significant engine design
changes would be required to incorporate and adapt emission
technologies for use into any prototype portable generators. The
commenters assert that engine designs that incorporate the prototype
design changes are possible, but may not be suitable for all engines,
especially when considering price and reliability considerations.
Response: To reduce the CO exhaust levels in portable generator
units, staff developed the prototype generator with commercially
available parts for better fuel delivery controls and exhaust emission
controls. The prototype generator did not require extensive design
changes. The prototype generator engine was derived from a readily
available unit with a carburetor-equipped engine, which was retrofitted
with sensors and components for electronic microprocessor controls of
the intake manifold fuel injection and combustion spark timing. The
prototype engine with electronic fuel controls required no disassembly
between the engine cover, engine block, or cylinder head. Therefore,
the head gasket and cylinder compression rings were left in their
original condition. Considering price, staff agrees that there is an
added cost to EFI engines, as discussed in the preliminary regulatory
analysis. As to reliability, staff notes that the prototype generator
was successfully tested for its longevity in service (durability) for
500 hours, which was the rated useful life, as established by the
manufacturer.
Staff notes that the CPSC prototype generator was meant to be a
durability program demonstration to support substantially reduced CO
emission rates and encourage research on an approach to mitigate the
risk of fatal and severe CO poisoning. The prototype portable generator
was not intended to be a production unit, as manufacturers would need
to consider appropriate suitable designs for their engine families in
portable generators. Staff's prototype findings have since been
repeated by others who patterned their reduced CO emissions prototype
generators on the design concept developed for CPSC by the University
of Alabama.\72\
---------------------------------------------------------------------------
\72\ See Techtronic Industries (TTi) presentation 3/17/16 at
PGMA's Technical Summit on Carbon Monoxide Hazard Mitigation for
Portable Generators--pages 85-105 of 178 page pdf file at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
---------------------------------------------------------------------------
2. Comment: The Truck and Engine Manufacturers Association (EMA)
asserts that similar engine designs, including basic fuel-injection and
ignition design are uniform across several manufacturers' product lines
of gasoline-fueled engines, where possible. Products like lawn mowers
and portable generators may use a similar engine design and components,
and EMA states that this uniformity across many products provides
manufacturing flexibility and economy of scale. EMA states the
implementation of a different engine design in portable generators,
such as described in the prototype program, may impact cost and
availability of the product.
Response: The prototype design was specifically originated and
developed through available off-the-shelf electronic fuel controller
and components adapted onto an existing marketed portable generator
engine. The prototype generator was successfully tested for its
longevity in service (durability) for 500 hours, which were the
longevity and emission outcomes of the new EFI engine through the rated
useful life, as established by the manufacturer.
CPSC staff acknowledges the EMA concern that adoption of a portable
generator engine, specifically designed to reduce CO emissions, may
have
[[Page 83574]]
different engine components pricing compared to the current portable
generator engine without the emission reduction. CPSC staff notes that
portable generators with EFI (though not specifically designed for low
CO emissions) have been increasing in availability in the market as new
models have been introduced.
3. Comment: Honda states that the photos of the prototype unit
cylinder head in the University of Alabama report, Prototype Low Carbon
Monoxide Emission Portable Generator Build Description and Performance
Evaluation,\73\ may indicate that combustion gases had been leaking to
the outside because the head gasket was in the early stages of failure
prior to the time that the engine was disassembled. Honda indicates
that they made these findings based on the carbon deposits on the
prototype cylinder head fin and head gasket seating surface, shown in
the photos in Figure 22 of UA's report.
---------------------------------------------------------------------------
\73\ UA's report (Puzinauskas, P, Dantuluri, R, Haskew, T,
Smelser, J, . Prototype Low Carbon Monoxide Emission Portable
Generator Build Description and Performance Evaluation,, The
University of Alabama, Tuscaloosa, AL, July 2011) is available as
TAB G in the staff report referenced previously (Buyer, Janet,
Technology Demonstration Of A Prototype Low Carbon Monoxide Emission
Portable Generator, September 2012.)
---------------------------------------------------------------------------
Response: The cylinder heads, pistons and several other components
are photographed and compared in the post durability wear analysis
section of Contractor University of Alabama's report, Low Carbon
Monoxide Emission Prototype Portable Generator Build Description and
Performance Evaluation. Figure 22 in UA's report shows a side-by-side
comparison of the cylinder heads from the baseline generator (an
unmodified unit) to the prototype generator unit after completion of
the 500 hours of durability testing. CPSC staff partly agrees with the
Honda photo assessment because more carbon deposits are visible on the
prototype cylinder head gasket surface, compared to the same component
in the baseline. However, the prototype's head gasket endured
approximately 585 engine hours of the durability program and subsequent
emission testing. According to UA's report, the head gasket with the
baseline unit leaked after 175 engine hours into the durability test
and was replaced. The cylinder head photos, which compared the
generator units after completion of the durability test, showing less
carbon deposit on the baseline engine's cylinder head gasket seating
surface may be explained by fewer accumulated engine hours on the newer
head gasket. Furthermore, staff notes that the prototype engine had
been run for 585 hours by the time the photograph was taken, which was
85 hours beyond the manufacturer's rated useful life of the engine.
4. Comment: Honda states that that the increased combustion
temperature due to the prototype's stoichiometric air-to-fuel mixture
and reliance on radiant cooling is insufficient, as evident in the
condition of photographed engine components, such as the pistons, after
completion of the durability test.
Response: CPSC staff agrees with Honda that leaner fuel ratios
generally result in increases in combustion temperatures. Increasing
the air-to-fuel ratio available for combustion was intentional in the
prototype engine, to influence and reduce the CO mass flow in the
exhaust emission. Cylinder head temperatures were measured in generator
units at all various load profiles for each occurrence of emission
testing. These emission tests occurred before modifications to engine
or durability testing, during the durability testing, in which hours of
engine operation were accumulated, and after the durability tests.
Emission and engine test data were collected on the as-received,
carburetor-fueled generators units. According to the University of
Alabama report, Low Carbon Monoxide Emission Prototype Portable
Generator Build Description and Performance Evaluation, the as-received
generator unit selected to become the prototype, but not yet modified,
measured a 13.98 AFR at full generator loading (mode 1), with an
associated 227 [deg]C cylinder head temperature. In addition, the range
of AFR values for this pre-modified prototype generator measured 13.98-
11.26, with progressively richer AFRs toward idle or no-load. The
maximum cylinder head temperatures with the stoichiometric EFI after
prototype engine modification were no hotter than the original unit.
Staff believes that the 14.0 AFR carburetor design offered no cylinder
head cooling capacity over the stoichiometric EFI design. Throughout
the prototype generator program, including independent laboratory
dynamometer emission testing after 500-cyclic engine hours of
operation, the engine demonstrated a cylinder head temperature less
than 227 [deg]C at full load. The mid-to-no load operating temperatures
were cooler. All of these recorded measurements of the prototype
cylinder head temperatures, including full load, were well below the
manufacturer-recommended temperature limits.
Another comparison of cylinder head temperatures involves the
baseline generator, which remained unmodified as the original unit, and
the prototype generator. According to the Low Carbon Monoxide Emission
Prototype Portable Generator Build Description and Performance
Evaluation report, the carburetor fuel system of the baseline generator
delivered 13.4 to 10.5 AFR values for the range of generator loads
throughout the durability program. Similar to the pre-modified
prototype generator, progressively richer AFRs occurred in the baseline
generator towards idle or no-load. Alternatively, the prototype
generator fuel strategy sought to maintain the same stoichiometric AFR
across all loads. These differences in AFR values created an average
elevated temperature of 28 [deg]C in the prototype unit to the baseline
unit. Staff believes the 28 [deg]C average hotter temperatures across
all loads created more discoloration in the prototype piston. There
appears to be more blackened areas of the piston ring, and more
coloring below the seated position of the piston ring indicate hotter
operating temperatures in the prototype cylinder compared to the
baseline unit. However, as mentioned, the recorded measurements of the
prototype cylinder head temperatures, including full load, were well
below the manufacturer recommended temperature limits. For the
technology demonstration program, the prototype's leaner AFR to
minimize CO exhaust production was believed to be balanced with higher,
but acceptable, cylinder temperatures.
5. Comment: EMA states that greater CO emission levels occurred
with the prototype portable generator at 500 hour end-of-life compared
to zero hour, suggesting that some deterioration of the prototype
engine occurred with accumulation of engine hours.
Response: The UA report contains an appendix with prototype and
baseline generator engine-hour durability emission test results for
low-, high- and mid-life engine hours. This appendix shows prototype
portable generator post-catalyst CO emission results at 2 g/kW-hr near
0 engine-hours and 17.5 g/kW-hr at 500 engine-hours. Staff does not
believe that these results reflect deterioration, but rather, a mid-
load controller calibration performance issue, which surfaced primarily
in the post-durability emission tests.
This 500-hour prototype emission test performance was due to
portions of the fuel look-up tables \74\ that were not
[[Page 83575]]
calibrated in the initiation of the engine build. Initially, it was not
known that rated engine speeds supporting an alternator would involve
extensive variation. Therefore, only certain areas of the controller
look-up tables were mapped. Retrospectively, it is known that the mode
4 or mid-load solution was simply to expand the same parameters
throughout the ECU look-up tables and all engine speeds. In the final
emission tests, larger AFR excursions and higher CO emissions occurred
when the engine operated in the unmapped portions of the controller.
While the post durability prototype generator CO emissions results show
more than 90 percent reduction over the baseline unit, the emission
reduction with the prototype could likely be reduced further with more
comprehensive calibration of the controller.
---------------------------------------------------------------------------
\74\ The fuel look-up tables are part of the electronic
programming of the Engine Control Unit (ECU) of the EFI system. The
tables are used to associate engine operating parameters measured by
the system's sensors with how much fuel the injectors need to
deliver to the combustion chamber in order for the EFI system to
maintain the desired air/fuel mixture.
---------------------------------------------------------------------------
6. Comment: Honda states that the CPSC testing did not evaluate
engine and generator performance in transient load conditions of
performance.
Response: The empirical testing in the NIST test house included
transient loads. NIST Technical Note 1781,i Modeling and
Measuring the Effects of Portable Gasoline Powered Generator Exhaust on
Indoor Carbon Monoxide Level, describes how NIST evaluated the
performance of both the prototype and baseline unmodified generators in
the garage, with several electrical loading variations, including the
generator cyclic load profile in the durability program and emission
testing.\75\ The measuring test equipment at the NIST test house
continuously collects CO measurements as the electrical and engine load
profile was altered. The proposed performance requirement is based on
measuring emissions while the generator is operating with a steady load
applied, as opposed to a transient load.
---------------------------------------------------------------------------
\75\ Emmerich, S. J., A. Persily, and L. Wang, Modeling and
Measuring the Effects of Portable Gasoline Powered Generator Exhaust
on Indoor Carbon Monoxide Level (NIST Technical Note 1781), National
Institute of Standards and Technology, Gaithersburg, MD, February
2013 (available online at: http://www.cpsc.gov/Global/Research-and-Statistics/Technical-Reports/Home/Portable-Generators/PortableGenerators041213.pdf and in: www.regultations.gov in docket
identification CPSC-2006-0057-0005.)
---------------------------------------------------------------------------
7. Comment: Two commenters asserted that CPSC's prototype
components may cause exacerbated reliability issues after long-term
storage.
Response: Staff disagrees because fuel-injection improves
reliability. A fuel-injected system is sealed, so the fuel is not
exposed to air like the vented system associated with a carburetor.
Exposure to air significantly contributes to degrading gasoline during
long-term storage and, in turn, causes problems with starting and
running the engine. Manufacturers advertise improved reliability as one
of the benefits associated with fuel injection.
Comment: One commenter asserted that it is harder to apply EFI and
catalyst on the smaller engines used in 1 kW-3 kW units and that they
are sold in higher numbers than 5 kW units. In a similar comment,
another commenter noted that CPSC's prototype used a commercial-grade
engine in open frame, yet closed-frame units are more popular.
Response: CPSC has observed that there are fuel-injected handheld
Class I engines, with and without catalysts, in the marketplace. CPSC
acknowledges, however, that there may be more challenges associated
with implementing the emission control technology on these smaller
engines and the generators that these engines power. Thus, there is a
later compliance date in the proposed rule for these models, relative
to the larger generators powered by Class II engines. Based on CPSC
staff's analysis of the market data, CPSC concurs that smaller
generators are becoming more popular, relative to larger generators.
CPSC staff used a larger generator, powered by a class II, single-
cylinder engine, in the technology demonstration program because the
Commission's incident data show that generators with these engines were
associated with almost two-thirds of the CO deaths involving generators
that have been reported to CPSC, when the size of the generator was
identified, for the years from 2004 through 2012. The lower proposed
performance requirements for smaller generators are expected to reduce
deaths that could otherwise be expected to occur with increasing
popularity of these smaller units.
8. Comment: One commenter stated that stable engine operation under
transient loads requires richer-than-stoichiometric AFR. Without it,
the commenter asserted, there is unreliable operation, which can result
in damaged electrical loads and warranty claims.
Response: The Commission acknowledges this operating challenge, and
for this reason, the proposed performance requirement is based on
measuring emissions while the generator is operating with a steady load
applied, as opposed to a transient load.
9. Comment: One commenter noted that their company uses more severe
modes and requirements to test product durability, which they are
doubtful the prototype would have survived. In a related comment, a
commenter asserted that significantly reduced CO emissions at the
highest loads resulting from operation near stoichiometric fuel control
will negatively impact engine durability.
Response: The Commission notes that the proposed performance
requirement for generators powered by class II single-cylinder engines
is nominally six times higher (less stringent) than the CO rate that
the prototype generator achieved. The Commission believes that the
proposed CO emission requirements can be achieved on many existing
engines by replacing the carburetor with closed-loop EFI and
integrating a catalyst without engine design modification and without
negatively impacting engine durability. The Commission notes, however,
that for some engines, modifications might be needed to enable
operation closer to stoichiometry. For other engines that cannot be
improved through design modifications, those could still be used in
generator applications by using a product integration strategy that
precludes installed engine operation at loads where fuel enrichment is
needed.
10. Comment: One commenter stated that the performance standard for
CO emission rates must take into account deterioration of emissions to
achieve the target exposure over the life of the engine.
Response: The Commission took deterioration into account in
developing the performance requirements. The Commission believes
deterioration of CO emissions to be minimal. This is based on both the
performance of CPSC's durability-tested prototype at end of life as
measured by CES, as well as by observation of published deterioration
factors for CO, which are measures of the increase in CO emissions for
an aged engine, relative to its emissions when new. The Commission
observed in the EPA's exhaust emission database for model year 2015
that a vast majority of the engines have a deterioration factor below
1.1 (thus indicating the emissions worsen by less than 10 percent above
initial emissions).
11. Comment: One commenter stated that the target CO emission rate
in terms of g/kW-hr should be based on engine displacement, with lower
rates (in terms of g/kW-hr) for larger engines to achieve the same
target exposure.
Response: The Commission believes lower CO emission rates are
technically feasible for smaller engines, compared to larger engines.
Consequently, the Commission is proposing performance requirements for
four different size
[[Page 83576]]
categories of generators that are each based on technical feasibility
and analysis of benefits and costs as a function of engine
displacement, and, for the largest category, also whether the engine
has one or two cylinders. The epidemiological benefits considered
exposure differences for different generator types, by allocating known
incidents based on location of generator and location of victims in
various house types.
12. Comment: One commenter asserted that reducing CO emissions will
increase other pollutant emissions and risk of fire and burn hazard.
Response: The Commission does not agree that reducing CO emissions
will increase other pollutant emissions. Based on the emission results
from CPSC's prototype generator, as well as those from the EPA's
demonstration program, reducing CO emission rates also results in
reduced HC+NOX emissions. CPSC staff acknowledges that for
CPSC's prototype, the leaner air fuel ratio resulted in elevated
exhaust temperatures compared to the carbureted configuration. Staff
notes, however, that the muffler that was used was chosen to easily
accommodate integration of the small catalyst into it. This muffler had
less internal baffling, which resulted in average muffler surface
temperatures of approximately 70[deg]C hotter than the OEM design. As a
result, UA shrouded this muffler and that resulted in shroud surface
temperatures that were lower than the OEM muffler that was not
shrouded. Staff notes that use of better designed mufflers, and, if
needed, improved flow of cooling air over the exhaust, could mitigate
the effect of elevated exhaust temperatures.
13. Comment: One commenter stated that EFI systems are becoming
more low cost and noted that an oxygen sensor of one particular design
can serve as a safety switch if the engine starts operating rich of
stoichiometric.
Response: The Commission has observed that small SI engines with
EFI have entered the marketplace in recent years, and expects this
would mean that they have become less expensive. The Commission is
interested in combining reduced CO emissions with a mechanism that will
shut off a generator when operated in an enclosed or semi-enclosed
space.
14. Comment: One commenter stated that the results from testing the
generators in NIST's garage should not be relied upon for any
rulemaking related to portable generator safety because, the commenter
asserted, the attached garage on NIST's test house is not sufficiently
representative of how garages are conventionally constructed.
Response: The Commission used the results from NIST's test house to
provide an example of the reduction in the house's hypothetical
occupants' exposure that the reduced CO emission rate from a portable
generator can yield when compared to a current carbureted generator
when operated in the same garage. The Commission is basing the proposed
performance requirements for the rule on technically feasible CO
emission rates, along with an assessment of the impact of those rates
through indoor air quality modeling of 40 structures, representative of
the U.S. housing stock, where generators were operated in 503 of the
deaths in CPSC's databases that occurred from 2004 through 2012.
15. Comment: Several commenters expressed concern about CO deaths
caused by generators and expressed support for reducing generators' CO
emission rates and their belief in the technical feasibility to do so.
Response: The Commission agrees with the commenters.
C. CO Poisoning Effects
1. Comment: The commenter considers that CPSC staff assumes COHb
levels below 10 percent are not harmful. The commenter notes that there
is no scientific basis for such an assumption and also notes that, in
many studies, COHb levels do not correlate consistently with symptoms.
Response: The Commission does not assume that a CO exposure
resulting in less than 10 percent COHb is incapable of causing adverse
health effects. The Commission has long recognized the existence of
populations especially sensitive to CO health effects (fetuses,
asthmatics, and individuals with cardiovascular diseases). Most
authorities, including CPSC, consider individuals with coronary artery
disease [CAD] to be the population most sensitive to potential adverse
health effects of CO at the lowest exposure levels. Some studies report
individuals with CAD might perceive adverse health effects, and/or,
tests show that they may experience adverse health effects that they
are unaware of, at about 2 percent to 5 percent COHb. The Commission
understands that the pathophysiological effects of CO are complex and
strongly influenced by multiple factors, particularly CO level,
exposure duration, and exposed individual's inhalation rate and health
status. In the ANPR on portable generators, and in the prototype report
documents, CPSC focused on extremely high-level, acutely lethal, CO
exposures caused by generator exhaust. Therefore, rather than provide
an exhaustive review of all studies, including equivocal findings in
some low-level exposure studies, CPSC is providing an overview of the
complex interactions between multiple variables that influence the end
effects of acute, high-severity CO exposures in humans. CPSC emphasizes
that CO poisoning effects should be understood to be a continuum of
effects of the exposure, rather than be viewed as discrete health
effects tightly tied to specific CO levels or COHb levels.
2. Comment: One commenter stated that although a low CO emissions
generator would undoubtedly save lives if widely applied, ``prediction
of confusion and incapacitation from COHb levels is not possible.'' The
commenter cited his recent publication reporting that ``symptoms of CO
poisoning do not correlate well with COHb levels.'' Based on his
findings and other clinical reports, the commenter questions the
validity and/or concept of a table relating COHb levels to particular
symptoms, as used by the Commission. The commenter believes that it is
incorrect to use COHb levels to calculate egress times from a CO-
containing environment and notes that there are no data to support the
method. Another commenter also questioned the validity of an
approximate relationship between COHb levels and severity of CO
poisoning symptoms and health effects.
Response: The Commission's use of predicted COHb levels was not
intended to calculate an actual egress time from a CO exposure, and the
Commission noted that reduced emission generators would not guarantee
egress by exposed individuals. Rather, the Commission considers that
reduced generator CO emissions, as achieved with its prototype unit,
will substantially delay the rate at which CO levels rise in poorly
ventilated spaces, and will thus delay the rate at which COHb levels of
exposed individuals rise (in some cases reducing the peak COHb level
attained). This will provide significantly increased time available for
individuals to remove themselves from the exposure environment or to be
rescued by an outside party. Supporting evidence that some individuals
will react appropriately to slower onset of CO poisoning effects has
been reported (e.g., 111 of 167 patients with CO poisoning presented to
Florida hospital emergency departments (ED) between 5 a.m. and 10 a.m.,
after waking and feeling ill consequent to overnight use of a generator
during hurricane-related power outages). CPSC data indicate that in 69
of 93 cases where it was known
[[Page 83577]]
how and why a patient with generator-related CO exposure presented to
an ED, the patient had either transported themselves or contacted
others (9-1-1, family, friends) to arrange for their transport to the
ED. In the remaining cases, individuals were found in distress by
others (either a lesser affected co-exposed individual or an outside
party).
The Commission recognizes that even healthy individuals can exhibit
variability in individual susceptibility to CO health effects under
identical exposure scenarios. The Commission understands that, in
clinical situations, CO poisoning symptoms and health effects do not
necessarily correlate well with a patient's initial COHb measurement,
which is often confounded (generally reduced by factors such as time
interval relative to cessation of CO exposure and provision of
supplemental oxygen). Clearly, COHb measurements can be of limited
value to physicians when determining appropriate treatment plans for
individual patients. Rather than make clinical decisions, the
Commission needed to provide controlled, systematic comparisons of how
CPSC's reduced CO emissions prototype generator could be expected to
reduce the lethal CO hazard presented by the unmodified original
generator. Therefore, CPSC used identical physiological input
parameters for a healthy adult to model COHb formation and elimination
from empirical generator CO time course exposure data. CPSC used
predicted times taken to rise to, and progress through, three
convenience benchmark percentile COHb values to compare the relative CO
poisoning hazard presented by a generator before and after design
modifications to reduce its CO emission rate. The Commission considered
these benchmark values to approximate relatively mild (20% COHb),
potentially incapacitating (40% COHb), and likely lethal (60% COHb)
exposure levels. Although indicating health effects generally first
reported at these benchmark COHb levels, CPSC did not intend to convey
that they represented precise measures when appearance of symptoms and
adverse health effects would be expected in all individuals. CPSC noted
that rapidly rising, high-level CO exposures of several thousand ppm
(as can occur with current carbureted generators) would result in
extreme oxygen deprivation and fast-rising COHb levels, causing rapid
incapacitation, loss of consciousness and death, without individuals
necessarily experiencing milder, progressively worsening CO poisoning
symptoms typically manifested in slowly rising or lower-level CO
exposures.
As further detailed in the staff's briefing package, the available
physiological research data and clinical findings in the scientific
literature support the use of ``COHb benchmarks,'' for approximate
estimation and comparison of CO-related health effects expected during
generator-related exposures.\76\ The Commission welcomes suggestions on
alternative health-based approaches to compare the reduced CO emissions
generators with current products in terms of improved safety benefits.
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\76\ Tab K, Appendices, of staff's briefing package.
---------------------------------------------------------------------------
D. Jurisdiction
Comment: One commenter asserted that pursuant to Sec. 31 of the
CPSA, the CPSC lacks authority to regulate the risk of injury
associated with CO emissions from portable generators because that risk
could be addressed under the Clean Air Act (CAA). Specifically, the
commenters rely on Section 213 of the CAA, which directs the EPA to
conduct a study of emissions from non-road engines to determine if they
cause or contribute to air pollution, ``which may reasonably be
anticipated to endanger public health or welfare.'' 42 U.S.C.
7547(a)(1)(2006). Under this provision of the CAA, the EPA has
promulgated regulations governing CO emissions from portable
generators. In particular, 40 CFR part 90 imposes requirements to
control emissions from non-road spark-ignition engines, which includes
portable generators, at or below 19 kilowatts.
Response: Section 31 of the CPSA does not establish an absolute
prohibition to CPSC action whenever the CAA is implicated. Rather, the
Commission lacks authority to regulate a risk of injury associated with
a consumer product if that risk ``could be eliminated or reduced to a
sufficient extent through actions'' taken under the CAA. 15 U.S.C.
2080(a). Case law and the legislative history of Sec. 31 confirm this.
See ASG Industries, Inc. v. Consumer Product Safety Comm'n, 593 F.2d
1323 (D.C. Cir. 1979) (under section 31, CPSC is to consider all
aspects of the risk and make a judgment whether the alternate statute
can sufficiently reduce the risk of injury).
The legislative history indicates that Congress contemplated a
stricter ban on the CPSC's jurisdiction and rejected it. Specifically,
the Senate version of the bill for Sec. 31 would have precluded CPSC's
jurisdiction if the product was ``subject to safety regulations'' under
one of the statutes listed in section 31 of the CPSA. S. Rep. No. 92-
749, 92d Cong., 2d Sess. 12-13 (1972). In contrast, as the ASG court
noted, under the House version of the bill, which was eventually
enacted, the Commission has authority if there has not been sufficient
reduction or elimination of the risk of injury. H.R. Rep. No. 92-1593,
92d Cong., 2d Sess. 38 (1972).
The CAA and the EPA regulations promulgated under it that address
CO emissions from portable generators have not sufficiently reduced or
eliminated the risk of CO poisoning associated with portable generators
that the CPSC seeks to address. Deaths and injuries associated with CO
emissions from portable generators have increased since the EPA adopted
its regulations limiting CO emissions from the type of engines used in
portable generators.
The CAA and the EPA's regulations create national standards
intended to address large-scale ambient air pollution, not acute CO
exposure from portable generators. The CAA and the EPA's regulations,
created under 42 U.S.C. 7407, are designed to reduce CO emissions in
regional areas that exceed National Ambient Air Quality Standards.
These requirements are not designed to reduce the localized risk to
consumers from acute CO poisoning when portable generators are used in
the home.
Additionally, EPA's 2008 adoption of an averaging program for CO
emissions from marine engines further demonstrates that its regulations
are not concerned with the risk of acute CO poisoning, but only large-
scale overall emission levels. This averaging program allows a
manufacturer to exceed the EPA's CO emission limits for a group of
similar engines, as long as the manufacturer offsets that increase with
another ``engine family'' with emission levels below the EPA's limit.
73 FR 59,034 (Oct. 8, 2008). It is noteworthy that this averaging
program applies to CO emissions from marine engines, which the EPA
explicitly acknowledges are associated with ``a substantial number of
CO poisonings and deaths.'' 73 FR 59,034, 59,048 (Oct. 8, 2008). Under
this program, emissions from an individual engine are inconsequential
to EPA's rule, and so is the individual consumer's exposure level.
Rather, the EPA's determination of CO emission limits focuses on
ambient air pollution on a large scale.
Finally, the structure of the CAA and its delegations of authority
make the EPA unable to adequately address the risk of injury associated
with CO poisoning to consumers from portable
[[Page 83578]]
generators. Under the CAA, the EPA sets National Ambient Air Quality
Standards (NAAQS) and has oversight and enforcement authority, but the
states retain primary responsibility for ensuring air quality. Section
107 of the CAA sets out states' responsibilities for ensuring air
quality, including determining how the state will meet NAAQS, and
identifying attainment and non-attainment areas. 42 U.S.C. 7407. The
U.S. Supreme Court has emphasized that the EPA is ``relegated by the
[CAA] to a secondary role,'' as long as states adopt plans that meet
the general requirements. Train v. Natural Resources Defense Council,
Inc., 421 U.S. 60 (1975). This broad leeway provided to states
indicates that the CAA and the EPA's regulations are not intended to
and cannot provide sufficient specificity to mitigate the risk of CO
poisoning.
E. CO Sensor Systems and Exhaust Pipe Extension
1. Generator-Mounted CO Sensing Shutoff Systems
Comment: Four comments were submitted on the concept of a
generator-mounted safety shutoff system using CO sensing technologies
that could be used to limit consumer exposure to CO present in portable
generator exhaust. Three of the four commenters advocated for such a
system, and one advocated against it.
One comment in support of the use of residential CO alarm
technology noted that a CO sensor that is used to activate ventilation
systems in parking garages can be used for turning off the generator
when it senses 35 ppm CO. The Commenter also recommended that the
system be interlocked to prevent generator operation every 2 to 3
years, when the sensor's useful life is expended, and to prevent
operation, if the user disables the system.
The commenter who did not recommend the use of residential CO alarm
technology expressed the belief that COS sensing technology near a
generator may impair its operation, causing users to disconnect the
sensors to ensure a steady source of electricity. The Commenter also
noted that CO sensors require routine maintenance, and their
capabilities can degrade with time and during extended periods of
inactivity, adding that it may be unreasonable to expect consumers to
regularly check and maintain the CO sensing equipment, particularly
when the generator is not even being used.
Response: The Commission shares the concern that using CO sensing
technology in the vicinity of a portable generator may impair the
generator's operation, causing users to disconnect the sensors. The
Commission agrees that it is unreasonable to expect consumers to
regularly check and maintain CO sensing equipment, particularly when a
generator is not being used. Early in the portable generator project,
the Commission investigated one version of the concept of an on-board
CO sensing shutoff system; the investigation and its findings are
documented in the staff report, Phase 2 Test Report: Portable Generator
Equipped with a Safety Shutoff Device (Brown, 2013). Its goals were to:
(1) Determine if a CO sensor/alarm output signal from commercially
available residential CO alarms (meeting the requirements in UL 2034
Single and Multiple Carbon Monoxide Alarms), when retrofitted with
circuitry connected to the generator, could trigger a shutoff device
installed on a portable generator when the CO alarm activated; and (2)
measure CO concentrations around the generator when operated in
multiple environments to assess CO migration and levels that might
occur under several scenarios. Test environments examined included
outdoors, in a two-sided structure, as well as inside and under a
temporary modular storage (TMS) building.
In that investigation, the Commission found that when the generator
was operated inside the TMS building, the CO migrated and accumulated
on the far side of the room more quickly than near the generator. The
CO alarms on the generator never activated before those located
elsewhere in the space activated, with the time difference generally
ranging from 5 to 10 minutes. In some tests, CO levels in some parts of
the room reached up to 1,000 ppm before the CO alarm on the generator
activated and shut off the generator. When the generator was operated
in wide-open outdoors in a light breeze condition, CO concentrations
ranging up to 350 ppm were measured in the immediate vicinity of the
generator. Although this did not activate the CO alarms mounted on the
generator to shut it off, the Commission believes this could occur in
some circumstances. This would detrimentally affect the utility of the
generator when used in a proper location.
In addition to these performance deficiencies, the Commission is
concerned about the ability of CO sensors to survive the environments
produced by an operating generator. Currently available electrochemical
and semiconductor CO sensors, which dominate the CO sensing market,
have numerous vulnerabilities that will compromise their ability to
maintain accuracy if they are used in an atmosphere containing high
concentrations of hydrocarbons, as is present in a generator's exhaust,
particularly when used in a confined space.
Regarding one commenter's recommendation to use CO sensors that
turn on ventilation fans in parking garages, a recent energy efficiency
study examining the performance of parking garages that have CO-sensing
activated ventilation indicates that this type of system is subject to
failure if not maintained on the manufacturer's recommended schedule
(California Utilities Statewide Codes and Standards Team, 2011).
Systems employing both electrochemical and solid state technology that
were five and 12 years old, respectively, failed likely because they
had not been calibrated. A properly maintained 2-year-old
electrochemical sensor-equipped system performed well. The commenter
suggested that to account for the referenced 2 to 3 year expected
sensor life, the consumer replace the sensor at the end of the sensor's
useful life. The Commission believes that it is not appropriate for
consumers to be required to replace a primary safety device, let alone
replace it every 2 to 3 years, when the life of the overall product is
much longer. Furthermore, making the sensor replaceable makes it
vulnerable to tampering. Notwithstanding the previously mentioned CO
concentrations that CPSC measured around a generator operating in a
proper location, the conflict between making the sensor consumer-
replaceable and tamper-proof leads the Commission to conclude that
currently available sensors are not likely to be effective, given the
long service life of portable generators. With respect to the
recommendation for a 35 ppm CO set point for an on-board sensor, CPSC
measured CO concentrations in excess of 35 ppm in the immediate
vicinity of the generator, while operating outdoors within 11 minutes
after starting the generator (Fig C2 in Brown, 2013). A 35 ppm limit
for shutoff would greatly limit the utility of portable generators when
used properly.
2. Remotely Located CO-Sensing Shutoff Systems
Comment: Two commenters raised concerns about the concept of a
remotely located CO-sensing shutoff system, such as that investigated
and documented in the staff report, ``Demonstration of a Remote Carbon
Monoxide Sensing Automatic Shut-Off Device for Portable Generators''
(Lee, 2006). Conceptually, a remotely located
[[Page 83579]]
CO-sensing shutoff system would use a CO sensor located indoors to
monitor for CO infiltration at that location and when it detects an
unsafe CO concentration there, the sensing shut-off device would
communicate with the generator to shut it off. The report presents CPSC
staff's investigation of one version of such a concept, consisting of a
CO alarm retrofitted with a wireless transmitter, placed by the user in
an indoor location, which communicated with a wireless receiver mounted
onto a portable generator operating in an attached garage. When the CO
alarm activated, it energized a circuit on the generator and shut off
the generator.
One commenter raised a number of behavioral and technical issues on
the utility of such a system. This commenter noted that the same
technical comments he made on the generator-mounted safety shutoff
concept, discussed above, apply to the remote-sensing concept as well.
This commenter also noted that remote-sensing technologies require
consumers to take affirmative actions to properly locate sensors inside
buildings and to monitor them to make sure that they continue to be
operational. The commenter stated that the risk of the CO poisoning
hazard would not be mitigated when consumers fail to locate or use the
sensing technology properly or the detector malfunctions due to
infrequent use or lack of maintenance.
Another commenter enumerated a number of concerns about the concept
of a remote CO-shutoff system that included:
Sensor performance affected by ambient conditions
battery life
the ability of consumers to install
nuisance trips causing consumers to disable system
the need to maintain proper battery charge
ability of consumer to start generator, then remove the remote
sensor to an area without CO, to allow the generator to operate.
Regarding the staff report, the commenter objected that only one
model generator was included in the tests and that only a limited
number of hazard scenarios were tested. The commenter provided a list
of options that would need to be investigated to document remote CO-
sensing device acceptability. The options include: (1) Effectiveness of
the mandatory warning label; (2) effects of environmental conditions on
CO dispersion in a building; (3) effect of generator load profile on CO
dispersion; (4) effect of walls and building materials on the sensor's
radio frequency (RF) signal to the generator; and (5) maximum distance
between sensor/transmitter and the generator. Additional areas the
commenter listed include: (6) Consumer's ability to reset the system in
adverse conditions (darkness, storms); (7) timing of product sales
(pre- or post-storm); (8) minimum component performance requirements;
and (9) minimum battery requirements.
Response: The Commission agrees that there are multiple challenges
with a remote CO-shutoff concept for portable generators, including
many of the challenges identified by the commenters and notes that the
staff report concluded with the following:
The study was limited to proof-of-concept and did not consider
issues such as life expectancy, reliability, usability, and
environmental conditions. All of these factors would need to be
considered in developing a remote CO detection/shut-off system for
portable generators for consumer use.
In addition to having the same sensor-related concerns as those
stated above in CPSC's response to the on-board CO sensing shutoff
concept, CPSC has additional concerns, a primary one being that a
system of this sort would need to be provided with the generator and
would require the consumer to properly install the sensing devices. The
consumer could easily defeat the features by operating the generator in
an enclosed location and intentionally placing the sensor outdoors or
other locations away from where the CO is infiltrating in order to keep
the generator running. Another scenario of concern involves the user
placing the CO sensor in a room where he/she thinks the CO will
infiltrate, but the CO infiltrates faster in another room that the
system is not monitoring. Transmitter range is another concern; if a
consumer properly locates the generator outdoors at a distance far
enough from the dwelling to prevent CO infiltration, the distance may
render the generator inoperable if it is not within range of the sensor
signal. Based on the concerns mentioned above, the Commission is not
pursuing this concept as a means of reducing the CO hazard associated
with portable generators.
3. Flexible Exhaust Pipe Extension
Comment: One commenter recommended using an exhaust hose that has
one end that fits over the tailpipe and a laterally expandable window
fitting on the other end to direct exhaust out through a window. The
commenter recommended that the hose should have an electrical circuit
wired through its entire length, which plugs into the generator to
prevent operation if the hose is not properly attached.
Response: There are several drawbacks to this approach. First, if
the hose must be attached for the generator to operate, then it must be
attached even if the generator is correctly located away from the
house. CPSC believes this is not practical. Second, the CPSC database
includes fatal CO incidents where the generator was located outside the
dwelling, but not so far away to prevent exhaust from entering the home
through leaks or openings (Hnatov, 2015). Third, CPSC staff believes
that it is unlikely that an expandable window insert can be installed
in such a way as to be leak tight. Last, this system's successful use
depends on the consumer's ability to properly install both the hose and
the window fitting. Given these concerns, the hose extension is not a
technically feasible approach to address the carbon monoxide poisoning
hazard associated with engine-driven portable generators.
F. Economic Considerations
On February 12, 2007, counsel for American Honda Motor Co., Inc.,
Briggs & Stratton Company, and Yamaha Motor Corporation, USA (the
companies), submitted comments jointly on the December 12, 2006 advance
notice of proposed rulemaking (ANPR), concerning portable generators.
The companies made the following comments on economic issues:
1. Comment: The vast majority of consumers use their portable
generators properly and safely. CPSC should give proper weight to the
benefits and widespread uses of portable generators, as well as the
affordability of current models.
Response: Although the great majority of consumers might exercise
proper safety precautions, improper use of the product can and does
have disastrous consequences. The Commission evaluated different
technologies to address the risk and has concluded that a performance
standard that sets requirements that reduce CO emissions from
generators is the most reliable regulatory alternative to address the
risks of CO poisoning associated with portable generators.
Manufacturing cost increases under the proposed rule would generally
have a relatively greater impact on percentage price increases (and
consumer demand) for low-price units, such as units lacking inverter
technology (as discussed in the preliminary regulatory analysis
section). However, the analysis finds that the
[[Page 83580]]
estimated benefits outweigh the costs to comply with the proposed rule.
2. Comment: Staff has not provided consumer exposure data to
support risk analysis of CO deaths associated with consumer use of
generators.
Response: Since the comment was filed, additional information and
analysis has greatly improved the analysis of risks associated with
consumer use of portable generators. The Commission's preliminary
regulatory analysis has analyzed historical shipment information
acquired from market research firms (Power Systems Research and
Synovate), from federal data sources (the International Trade
Commission and Bureau of the Census), and from individual manufacturers
to estimate the numbers of portable generators in use, by engine class
and other characteristics, during the period covered by CPSC staff's
epidemiological benefits analysis (Hnatov, Inkster & Buyer, 2016). The
new information and analysis has enabled CPSC to estimate CO poisoning
risks (and societal costs) per generator in use. Additional information
on product sales and use, which the industry is encouraged to provide
in comments to this NPR, could further refine these estimates.
3. Comment: In response to the technology demonstration report, one
commenter stated that although engine designs that incorporate the
report's design changes \77\ are possible, they may not be suitable for
all engines, including many used to power portable generators. This is
especially true when considering the price point and reliability
considerations associated with portable generators designed and sold to
consumers for emergency or infrequent use.
---------------------------------------------------------------------------
\77\ Mr. Gault is referring to the incorporation of an
electronic control unit, manifold air pressure sensor, fuel pump,
fuel injector . . . exhaust oxygen sensor, catalyst aftertreatment
and other components used on the prototype generator.
---------------------------------------------------------------------------
Response: As noted, we agree that some types of generators (and
engines) will be more severely affected by a proposed rule that is
performance based, but is likely to be addressed by manufacturers
through the use of EFI and catalysts (although some generators with
handheld engines might not require catalysts) in terms of relative
price increases that would result from incorporation of the
technologies. The impact on demand for these products could affect
their future availability to consumers.
IX. Description of the Proposed Rule
A. Scope, Purpose, and Compliance Dates--Sec. 1241.1
The proposed standard would apply to ``portable generators''
powered by small handheld and non-handheld SI engines, and would
include requirements intended to limit carbon monoxide emission rates
from these portable generators. The requirements are intended to reduce
an unreasonable risk of injury associated with portable generators.
Generators within the scope of the proposed rule provide receptacle
outlets for AC output circuits and are intended to be moved, although
not necessarily with wheels. Products that would not be covered by the
proposed rule include permanently installed stationary generators, 50
hertz generators, marine generators, generators installed in
recreational vehicles, generators intended to be pulled by vehicles,
generators intended to be mounted in truck beds, and generators that
are part of welding machines.\78\ Generators powered by compression-
ignition (CI) engines fueled by diesel also are excluded from the scope
of the proposed rule.\79\
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\78\ Stationary generators, marine generators, and generators
installed in recreational vehicles are excluded because they are not
portable. Generators intended to be pulled by vehicles, intended to
be mounted in truck beds, generators that are part of welding
machines, and 50-hertz generators are excluded because they are not
typically used by consumers.
\79\ CI engines are not typically used by consumers. In
addition, CI engines have relatively low CO emission rates. The
current EPA standard for CO emissions from CI engines rated below 8
kW is 8.0 g.kW-hr, which is significantly lower than the EPA
standard of 610 g/kW-hr applicable to small SI engine classes used
in portable generators.
---------------------------------------------------------------------------
The requirements would apply to four categories of portable
generators: (1) Handheld generators; (2) class 1 generators; (3) class
2 single-cylinder generators; and (4) class 2 twin-cylinder generators.
Handheld engines have total engine displacement of 80 cubic centimeters
(cc) or less; non-handheld engines include EPA Class I engines, which
have total engine displacement of less than 225cc, and Class II
engines, which have displacement of 225cc and more. Class II engines
have an upper limit determined by rated engine power, 19 kilowatts
(kW), which is equivalent to 25 horsepower. Although the Commission
categorized generators by the EPA classification of the engines
powering them, it is important to distinguish these engines from the
portable generators in which they are used because the engines are used
in other products as well. To provide a clear distinction, the
Commission refers to engines according to EPA's classification:
Handheld engines, non-handheld Class I engines and non-handheld Class
II engines, while referring to portable generators according to the
Commission's definitions, handheld generators, class 1 generators,
class 2 single-cylinder generators and class 2 twin-cylinder
generators.
Under the CPSA, the effective date for a consumer product safety
standard must not exceed 180 days from the date the final rule is
published, unless the Commission finds, for good cause, that a later
effective date is in the public interest. To meet the proposed
performance requirements, it is likely that engines will need closed-
loop fuel-injection, and with the exception of some handheld engines,
the addition of a catalyst. Implementing closed-loop EFI and catalyst
integration on all class II (single- and twin-cylinder) engines
powering generators may require design modifications, such as redesign
of cooling fins and a fan, to accommodate fuel control closer to
stoichiometry. The Commission believes 180 days may not be adequate
time to allow for such design modifications, and is instead proposing
an effective date of 1 year following publication of the final rule, at
which time portable generators with Class II single- and twin-cylinder
engines, or class 2 single- and twin-cylinder portable generators,
would be required to comply with the applicable requirements of the
rule. The Commission proposes a compliance date of 3 years after
publication of the final rule for generators powered by Class I engines
and handheld generators, or class 1 and handheld generators. This later
compliance date is to address manufacturers' concerns that, while
industry has gained some limited experience with incorporating fuel
injection on handheld and Class I engines, there may be different
challenges associated with accommodating the necessary emission control
technologies on these smaller engines. In addition, later compliance
dates potentially could reduce the impact on manufacturers of
generators, including small manufacturers, by providing them with more
time to develop engines that would meet the requirements of the
proposed rule, or, in the case of small manufacturers that do not
manufacture the engines used in their generators, by providing them
with additional time to find a supplier for compliant engines so that
their generator production would not be interrupted.
[[Page 83581]]
B. Definitions--Sec. 1241.2
The proposed standard would provide that the definitions in section
3 of the Consumer Product Safety Act (15 U.S.C. 2051) apply. In
addition, the proposed standard would include the following
definitions:
(a) handheld generator means a generator powered by a spark-ignited
(SI) engine with displacement of 80 cc or less.
(b) class 1 generator means a generator powered by an SI engine
with displacement greater than 80 cc but less than 225 cc.
(c) class 2 single-cylinder generator means a generator powered by
an SI engine with one cylinder having displacement of 225 cc or
greater, up to a maximum engine power of 25 kW.
(d) class 2 two-cylinder generator means a generator powered by an
SI engine with two cylinders having a total displacement of 225 cc or
greater, up to a maximum engine power of 25 kW.
C. Requirements--Sec. 1241.3
1. Description of Requirements
The proposed rule would require that portable generators powered by
handheld engines and Class I engines, or handheld and class 1
generators, not exceed a weighted CO at a weighted rate more than 75
grams per hour (g/h); generators powered by one-cylinder Class II
engines, or class 2 generators, must not exceed a weighted CO emission
rate of 150 g/h; and generators powered by Class II engines with two
cylinders, or class 2 twin-cylinder generators, not exceed a weighted
CO emission rate of 300 g/h. The weighted emission rates are based on
weighting of six modes of generator operation, ranging from maximum
generator load capability (mode 1) to no load (mode 6), similar to a
procedure used by EPA to certify compliance with its emission standards
for small SI engines.
2. Rationale
The proposed rule would impose different limits on weighted CO
emission rates for different categories of generators in recognition of
the effects of factors such as engine size and other engine
characteristics on CO emissions, in addition to the different
challenges that may be faced in meeting CO emission rates expressed in
grams per hour. The proposed rule would apply different criteria to
generators, based on EPA's classification of engines (and on the number
of engine cylinders), rather than on power ratings of either the
generators or the engines. This determination was based mainly on the
absence of standard methods for defining the rated power, maximum
power, or surge power of generators. Furthermore, staff determined that
the technically feasible emission rates were different for different
categories of generators. Staff also found differences in hazard
patterns for different categories; this is reflected in the
determination of epidemiological benefits (for example more fatalities
associated with large generators involved their use in garages as
opposed to basements, while for small generators the reverse was true,
as described in detail in staff's briefing package in Tab K).
The requirements of the proposed rule are based on technically
feasible emission rates and an analysis of the benefits and costs
associated with these technically feasible emission rates. The benefits
analysis and cost analysis are explained in detail in Section VI and
Section X, respectively, of this preamble.
D. Test Procedures--Sec. 1241.4
The proposed rule details the test procedure that the Commission
would use to determine compliance with the standard, but also provides
that any test procedure that will accurately determine the emission
level of the portable generator may be used.
The procedure the Commission would use is largely based on a test
method that was developed in a collaborative effort with industry
stakeholders and is explained in greater detail in Tab J of the
briefing package. In brief, the Commission intends to perform the tests
in ambient temperature in the range of 10-38 [deg]C (50-100 [deg]F)
using E10 gasoline. The six loads that will be applied to the generator
for determining the weighted CO emission rate are based on the
generator's maximum load capability. Maximum load capability is
determined by increasing the load applied to the generator to the
maximum observed power output, without causing the voltage or frequency
to deviate by more than 10 percent of the nameplate rated voltage and 5
percent of the nameplate rated frequency and can be maintained for 45
minutes with stable oil temperature. The loads will be applied using a
resistive load bank capable of achieving each specified load condition
to within 5 percent and will be measured using a power meter with an
accuracy of 5 percent. The Commission will use constant
volume sampling (CVS) emissions measurement equipment, as described in
the EPA's regulations 40 CFR part 1054 and 40 CFR part 1065 as of 2016.
If the generator is equipped with an economy mode or similar feature
that has the engine operating in low speed when not loaded, the setting
that produces the highest weighted CO emission rate will be used to
verify whether the applicable carbon monoxide emissions rate is met.
E. Prohibited Stockpiling--Sec. 1241.5
In accordance with Section 9 of the CPSA, the proposed rule
contains a provision that prohibits a manufacturer from ``stockpiling''
or substantially increasing the manufacture or importation of
noncomplying generators between the date of the final rule and its
effective date (or compliance date, in the case of generators with
handheld and Class I engines). The rule would prohibit the manufacture
or importation of noncomplying portable generators by engine class in
any period of 12 consecutive months between the date of the
promulgation of the rule and the effective/compliance date at a rate
that is greater than 125 percent of the rate at which they manufactured
or imported portable generators with engines of the same class during
the base period for the manufacturer. The base period is any period of
365 consecutive days, chosen by the manufacturer or importer, in the 5-
year period immediately preceding the promulgation of the final rule.
Generator sales can vary substantially from year to year, depending
upon factors such as widespread power outages caused by hurricanes and
winter storms. Annual unit shipment and import data obtained by CPSC
staff show that it has not been uncommon for shipments to have varied
by 40 percent or more from year to year at least once in recent years.
The 5 year period in the anti-stockpiling provision is intended to
allow manufacturers and importers sufficient flexibility to meet normal
changes in demand that may occur in the period between the promulgation
of a rule and its effective/compliance date while limiting their
ability to stockpile noncomplying generators for sale after that date.
Allowing manufacturers to produce noncomplying generators in amounts
that total 125 percent of their peak 365-day period over the prior 5
years could give manufacturers enough flexibility to respond to demand
if there is a year of major power outages that create a demand for
consumers to purchase portable generators. The Commission is aware of
some large manufacturers that have seen year-to-year shipments increase
by 50 percent and 70%, so the Commission believes that the allowable
stockpiling percentage over a base period should be greater for
generators than most other consumer products. The Commission
[[Page 83582]]
seeks comments on the proposed product manufacture or import limits and
the base period.
F. Findings--Sec. 1241.6
In accordance with the requirements of the CPSA, we are proposing
to make the findings stated in section 9 of the CPSA. The proposed
findings are discussed in section XVI of this preamble.
X. Preliminary Regulatory Analysis
The Commission is proposing to issue a rule under sections 7 and 9
of the CPSA. The CPSA requires that the Commission prepare a
preliminary regulatory analysis and that the preliminary regulatory
analysis be published with the text of the proposed rule. 15 U.S.C.
2058(c). The following discussion is extracted from staff's memorandum,
``Draft Proposed Rule Establishing Safety Standard for Portable
Generators: Preliminary Regulatory Analysis.''
A. Introduction
The CPSC is issuing a proposed rule for portable generators. This
rulemaking proceeding was initiated by an ANPR published in the Federal
Register on December 12, 2006. The proposed rule includes weighted
carbon monoxide emission limits from four different categories of
portable generators.
Following is a preliminary regulatory analysis of the proposed
rule, including a description of the potential costs and potential
benefits.
B. CPSC Staff Assessment of the Adequacy of Voluntary Standards for
Portable Generators in Addressing CO Deaths and Injuries
As indicated in Section VII.B of this preamble, two organizations,
Underwriters' Laboratories, Inc. (UL), and the Portable Generator
Manufacturers Association (PGMA), have been accredited by the American
National Standards Institute (ANSI) to develop U.S. safety standards
for portable generators. Although each organization has developed a
standard (designated as UL 2201 and PGMA G300, respectively), only
PGMA's standard has achieved the consensus needed to be recognized by
ANSI (as ANSI/PGMA G300-2015). A UL 2201 task group has been working on
developing proposals to address CO hazards of portable generators;
however, the task group has not yet sent a proposal to the standards
technical panel established by UL to consider for adoption into UL
2201. The current version of UL 2201 includes the mandatory CPSC label,
but does not otherwise address the risks related to CO poisoning. In
the Commission's view, the label alone is insufficient to address the
risk of injury from CO poisoning. CPSC is unaware of any portable
generator that has been certified to UL 2201. Therefore, it is unlikely
whether there would be substantial compliance with UL 2201 if the
standard were to incorporate CO emissions requirements (Buyer, 2016b).
PGMA G300 also includes the mandatory CPSC label for portable
generators, but it does not otherwise address the risks related to CO
poisoning. In a letter emailed to Chairman Kaye on September 19, 2016,
PGMA announced its intention to reopen G300 to develop a ``performance
strategy focused on CO concentrations.'' As discussed in Section VII.B
of this preamble, the Commission does not have an adequate basis to
determine that PGMA's modification to G300 would likely eliminate or
reduce the risk of injury or that there likely will be substantial
compliance with the voluntary standard, once modified. In addition,
based on the complex nature of setting CO limits and the fact that G300
is just now being re-opened, the Commission is not convinced that a
modification to the voluntary standard adequately addressing the risk
of injury identified in the rulemaking would be accomplished within a
reasonable period of time. CPSC believes that significant technical
work, requiring significant time, would be required to develop
appropriate requirements and test methods within the broad framework
identified in the PGMA letter \80\ and at a September 6, 2016, public
meeting between PGMA and staff.\81\ Specifically, as discussed at the
meeting and in the NPR briefing memorandum, there are several technical
concerns about shutoff criteria and testing that would need to be
investigated (Buyer, 2016a). The Commission is concerned whether the
test methodologies would be accurate, dependable and practicable and
sufficient to ensure that the generators would shut off quickly enough
in a sufficient number of common scenarios seen in portable generator
incidents to result in an adequate reduction in the risk of injury and
death. The Commission expects that significant periods of time will be
needed to evaluate each of these factors. For example, determining the
expected epidemiological benefits for the proposed rule required nearly
a year for NIST to conduct a modeling study and for staff to evaluate
the study. For the PGMA to develop an effective voluntary standard,
similar efforts will be required to assess the standard after the
technical details have been established.
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\80\ https://www.cpsc.gov/s3fs-public/PGMALtrChairKayeVoluntaryStandardFinal.pdf.
\81\ https://www.cpsc.gov/s3fs-public/09%2006%2016%20Meeting%20with%20PGMA%20Follow%20up%20on%20Technical%20Summit%20on%20Carbon%20Monoxide%20Hazard%20Mitigation%20for%20Portable%20Generators.pdf.
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C. Market Information
1. Manufacturers
Based on data obtained from Power Systems Research, Inc. (``PSR''),
a total of 78 domestic or foreign manufacturers produced or exported
gasoline-powered portable generators for the U.S. market in recent
years. However, most of these manufacturers were based in other
countries. The Commission has identified 20 domestic manufacturers of
gasoline-powered portable generators, 13 of which would be considered
small businesses based on the Small Business Administration (``SBA'')
size guidelines for North American Industry Classification System
(``NAICS'') category 335312 (Motor and Generator Manufacturing), which
categorizes manufacturers as small if they have fewer than 1,250
employees.
Few of the 78 firms involved in production for the U.S. market in
recent years have held significant market shares: Less than half of
these firms have reportedly had annual shipments of 1,000 units of
more, and only six firms have had annual shipments of 50,000 units or
more. From 2009 through 2013, the top five manufacturers combined for
an estimated 62 percent of the U.S. market for portable generators with
power ranges more likely to be in consumer use and the top 10
manufacturers combined for about 84 percent of unit sales during that
period. Under the CPSA, firms that import generators from foreign
producers would be considered manufacturers of the products. A review
of import records for portable generators found that the annual number
of individual importers of record has ranged from about 25 to 30 in
recent years. These firms would be responsible for certifying that the
products they import comply with the rule, should it be finalized by
the Commission.
2. Annual Shipments/Sales of Portable Generators
CPSC Directorate for Economic Analysis staff acquired information
on annual unit sales of portable generators through contract purchases
from market research firms, from federal data sources (e.g., the
International Trade Commission [ITC] and Bureau of the
[[Page 83583]]
Census), and other sources.\82\ Chart 1 presents information on sales
of portable generators for 1995 through 2014. Sales estimates are based
on estimated portable generator shipments and projected shipments to
U.S. retailers for the years 1998-2002 and 2007-2013 (RTI
International, 2006; \83\ Power Systems Research, 2012, 2013); \84\ and
estimated U.S. consumer purchases of portable generators for 1995-1997
and 2004-2008 (Synovate, 1999, 2006, 2009).
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\82\ Power Systems Research, compiled information on domestic
production and imports of portable generators from its OE
LinkTM market intelligence database of original equipment
and original equipment manufacturer (OEM) production & forecast
data. Synovate (which was purchased by another market research firm,
Ipsos, in 2011), based on analysis of surveys of the firm's
Continuing Consumer Survey panel and the firm's Multi-Client
Research Group (SMRG) sample.
\83\ RTI International (2006, October), Industry Profile for
Small Nonroad Spark-Ignition Engines and Equipment--revised draft
report. Authored by Alex Rogozhin, William White & Brooks Depro.
\84\ Power Systems Research, Inc. (2012, 2013), Excel data file:
OE LinkTM original equipment database, portable generator
sets produced and sold in the United States, Attached to email from
Marilyn Tarbet, PSR, to Charles Smith, Directorate for Economic
Analysis, CPSC, October 3, 2012, Excel data file: OE
LinkTM original equipment production--forecast database
with sales data, portable generators produced outside of the United
States, sold in the United States, Attached to email from Marilyn
Tarbet, PSR, to Charles Smith, Directorate for Economic Anaylsis,
CPSC, October 4, 2013.
[GRAPHIC] [TIFF OMITTED] TP21NO16.007
As shown by the chart, consumer demand for portable generators from
year to year fluctuates with power outages, such as those caused by
hurricanes and other storms along the Gulf and Atlantic coasts and by
winter storms in other areas. Periods of increased demand for portable
generators may be followed by reduced demand because a larger
percentage of households had made recent purchases. Evidence of the
importance of weather-related power outages in driving demand for
portable generators was highlighted in the fiscal 2007 annual report
issued by Briggs & Stratton, a leading manufacturer of engines used in
the production of generators (its own and others). The report, noted
that for 2007, the company had ``a 66% reduction of engine shipments
for portable generators caused by a lack of events, such as hurricanes,
that cause power outages'' (Briggs & Stratton, 2007). Additionally,
spurred by widespread concerns over the possible impact of Y2K in
disrupting power supplies, estimated portable generator shipments rose
to about 2.2 million in 1999, still the highest year for estimated
sales (RTI, 2006).
3. Product Characteristics of Portable Generators Shipped in Recent
Years
Power Ratings
Data obtained by the Commission in recent years show that portable
generators purchased by consumers and in household use generally range
from under 1 kW of rated power up to perhaps 15 kW of rated power. The
Commission believes that the most powerful portable generators are
mainly purchased for construction or commercial use, although some also
end up in household use.\86\ In Table 6, we present information on
generator power ratings for shipments of portable generators powered by
Class I or Class II engines for the U.S. market for the years 2010
through 2014, based on Commission analysis of data obtained from PSR,
import data from the U.S. International Trade Commission, and
information provided by individual firms. The generators are separated
into six power-rating categories. Over this 5-year period for
shipments, about 6.9 million gasoline-powered portable generators were
shipped for consumer use, or an average of about 1.4 million units per
year. Shipments of nearly 1.6
[[Page 83584]]
million units in 2013, made 2013 the peak year for sales during this
period.
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\86\ Although generator power ratings are only known for about
48 percent of the units involved in death reports as of May 21,
2015, for the period of 2004 through 2012, fewer than 3 percent of
these units had power ratings of 8 kW or greater, and the most
powerful unit involved was 10 kW (Hnatov. 2014).
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Data on recent portable generator shipments, as shown in Table 6,
compared to information on consumer purchases before 2010, indicate
that the U.S. market has shifted toward smaller, less powerful units.
Synovate surveys on generators purchased by consumers from 2004 to
2006, found that about 9 percent of units likely purchased for consumer
use (< 15kW) had continuous electrical outputs of under 2 kW and about
12 percent had ratings of 2-3.49 kW (Synovate, 2008). Data acquired
from PSR and individual manufacturers on portable generator shipments
in more recent years show that units with power ratings of under 2 kW
comprised an estimated 21 percent of the market, and units with power
ratings of 2-3.49 kW have held an estimated market share of about 36
percent over 2010 to 2014 (as shown in Table 6). The market share of
larger units, with outputs of 6.5 kW or more, fell from about 22
percent of the market in 2004 to 2006, to about 9 percent over 2010 to
2014.\87\
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\87\ It is possible that some of the demand for generators with
greater power in recent years has been increasingly met by sales and
installation of stationary stand-by generators.
[GRAPHIC] [TIFF OMITTED] TP21NO16.008
Engine Classes
Small spark-ignition engines used in the manufacture of portable
generators are classified (by EPA and for the CPSC proposed rule)
according to their total cylinder displacement in cubic centimeters
(cc). Data on this engine characteristic were obtained from PSR and
individual firms for recent shipments of portable generators, which
enabled CPSC to estimate engine classes for the kilowatt ranges
discussed above. Data on shipments of portable generators for 2010
through 2014 show that portable generators with Class I engines (those
with a total cylinder displacement of <225 cc) comprised about 59
percent of units shipped, and those with Class II engines (those with
total displacement >=225 cc) comprised about 41 percent. We estimate
that total annual shipments of portable generators over 2010 to 2014
averaged almost 1.4 million units; about 816,000 of these generators
had Class I engines and about 568,000 had Class II engines.
Although sometimes used in non-handheld equipment (such as portable
generators), engines are classified as handheld by EPA if they have
total displacement of less than or equal to 80 cc. Based on information
provided by PSR and individual firms, we estimate that generators with
handheld engines account for an average of about 10,000 to 20,000 units
sold annually; about 1 percent of the overall consumer market for
portable generators; and perhaps 2 percent of the units with smaller
(<225 cc) engines.
Chart 2 shows the relationship between rated kilowatt power of
portable generators and their engine classes for 2010 through 2014. As
can be seen, generators with rated power of under 2 kW were made with
Class I engines; and virtually all of those with rated power of 5 kW or
greater were made with Class II engines. For units with 2 to 3.49 kW
(which was the largest single kW category, accounting for 36 percent of
units in 2010 to 2014), the great majority (93%) were made
[[Page 83585]]
with Class I engines, while a majority (63%) of units with rated power
in the range of 3.5 to 5 kW were made with Class II engines.
[GRAPHIC] [TIFF OMITTED] TP21NO16.009
Engine Cylinders
Engines used in the manufacture of portable generators intended for
consumer use have either one or two cylinders for combustion of fuel.
Based on information on engine characteristics gathered and reported by
PSR, virtually all of the portable generators with sustained power
ratings below 6.5 kW that were sold from 2010 to 2014 were powered with
one-cylinder engines. These power categories comprised about 91 percent
of all units purchased by consumers during that period, as shown in
Table 1. PSR data reveal that one-cylinder engines powered about 91
percent of the generators with 6.5 to 7.99 kW and about 58 percent of
units with power ratings from 8 to 9.99 kW. It is in more powerful
generators, with sustained power ratings of 10 kW and greater, that
two-cylinder engines are more common, accounting for about 93 percent
of units sold from 2010 to 2014. Overall, the data indicate that one-
cylinder engines were used in the manufacture of at least 95 percent of
total unit sales of portable generators to consumers, and in about 89
percent of the Class II engines used to produce portable generators.
Fuel Distribution Systems
The Commission believes that compliance with the CO emission
requirements of the proposed rule likely would lead OEM manufacturers
of portable generators to select engines that have fuel distribution
systems that are more capable of controlling air-to-fuel ratios than
traditional carbureted systems.\88\ Specifically, manufacturers are
expected to switch to use of electronic fuel injection (EFI) instead of
conventional carburetors to control the delivery of gasoline to the
pistons of generator engines. The Commission is aware of at least five
portable generator manufacturers that have either developed models with
EFI for evaluation or actually marketed such models within the last 2
years; and some of these models have been evaluated by the Commission
at the National Product Test and Evaluation Center.\89\ However,
virtually all generators currently in consumer use have carbureted fuel
distribution systems.
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\88\ Tab I of staff's briefing package.
\89\ See Tab J of staff's briefing package.
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Engine Cycles
Spark-ignition engines used in portable generators have either two
or four piston strokes per combustion cycle. Two-stroke engines have
simpler designs with fewer moving parts, making them easier to maintain
and lighter in weight at a given displacement than four-stroke engines.
They also reportedly can produce up to 40 percent more power than four-
stroke engines with the same displacement (MECA, 2009). These
characteristics, and the ability to operate in many directions without
flooding, make two-stroke engines attractive for use in handheld
equipment, such as chainsaws, trimmers and leaf-blowers. Portable
generators and other larger non-handheld equipment, such as lawn and
garden equipment and pressure-washers, typically have 4-stroke engines.
Although all of the portable generators reported in PSR's database of
recent shipments had 4-stroke engines, the Commission found portable
units with small (<80 cc) 2-stroke engines advertised for sale on
internet Web sites. These units likely comprise an extremely small
share of the market for portable generators.
[[Page 83586]]
Retail Prices
With the wide range of engine power and other features available on
portable generators shipped in recent years, these products also have
been offered to consumers at a wide range of retail prices. The most
recent survey data on retail prices was provided to the Commission by
Synovate and covered the years 2004 through 2006. Consumer survey data
developed by Synovate found that the average retail price paid by
consumers for portable generators intended primarily for backup power
in the event of electric power outages (the primary stated purpose for
the purchase by about 75% of consumers) was about $1,040 in 2006.
More recent pricing information was gained through an informal
survey of advertised prices for portable generators by CPSC staff in
October 2015 (which included units available in stores and via the
Internet). This survey found that that retail prices generally vary by
kW rating of the units, engine class and number of cylinders. For rated
generator power, average prices were $393 for units under 2 kW; $606
for 2 to 3.49 kW generators; $640 for 3.5 to 4.99 kW units; $936 for
those with 5 to 6.49 kW ratings; $1,002 for units with 6.5 to 7.99 kW
ratings; and $1,745 for units with kW ratings of 8 or more. Generator
characteristics other than power ratings also affect price. For
example, ``inverter generators'' have electronic and magnetic
components that convert the AC power to DC power, which is then
``inverted'' back to clean AC power that maintains a single phase, pure
sine wave at the required voltage and frequency suitable for powering
sensitive equipment, such as computers. These additional components add
to the manufacturing cost, resulting in significantly higher retail
prices than units with similar power outputs. For example, our limited
retail price survey found that the average retail prices of generators
with power ratings of under 2 kW were $242 for units not identified as
inverters and $710 for those identified as inverters.
Regarding retail price information by engine class and number of
cylinders, staff's informal survey found that generators with handheld
engines ranged in price from $133 to $799, with an average price of
about $324. Generators with non-handheld Class I engines had a wide
price range, from $190 to more than $2,000, with an average price of
$534. Generators with one-cylinder Class II engines ranged in price
from $329 to $3,999, with an average price of $1,009. Generators with
two-cylinder Class II engines ranged in price from $1,600 to $4,999,
and the average price of these units was $2,550.
Table 7 shows selected characteristics (displacement, power rating,
price and weight) for generators found in an informal retail market
survey of generators, by engine class and type.
[GRAPHIC] [TIFF OMITTED] TP21NO16.010
D. Portable Generators in Use
In this section, we estimate the population of portable generators
in use, averaged over the period 2004 to 2012, analyzed by the
Directorate for Epidemiology, Division of Hazard Analysis.\90\
Estimates of the number of generators in use represent a measure of
[[Page 83587]]
risk exposure and is the necessary first step in calculating product-
related risks (e.g., generator-related deaths and injuries divided by
the population of generators in use), determining the per-unit societal
costs of deaths and injuries that would be addressed by the proposed
standard, and finally, estimating the possible benefits of the proposed
rule.
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\90\ Tab A of staff's briefing package.
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We estimated the population of portable generators in use with the
CPSC's Product Population Model (PPM), a computer model that projects
the number of products in use, given estimates of annual product sales
and their expected product life.\91\ The expected useful life of
generators, in years, is largely a function of engine size, loads
placed upon the unit and hours of use. Portable generators primarily
purchased for household backup power that are mainly used during
occasional or rare power outages could have useful lives much longer
than 10 years if they are maintained properly. An evaluation of data on
historical sales in relation to surveys of product ownership suggests
an expected useful product life of about 11 years. An assumption of a
considerably shorter expected useful life using data on historical
annual unit shipments would yield estimated numbers of units in use and
saturation rates that are well below those indicated by Synovate survey
data from 2005, as well as industry estimates of ownership in recent
years.\92\
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\91\ Lahr, M.L. & Gordon, B.B. (1980). Product life model
feasibility and development study. Contract CPSC-C-79-009, Task 6,
Subtasks 6.01-6.06). Columbus, OH: Battelle Columbus Laboratories.
\92\ For example, portable and stationary generator
manufacturer, Generac, reportedly estimated that about 12 percent of
households had portable generators in 2013, up from 10 percent in
2010 (Hill, 2013).
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Table 8 presents the product population estimates for the years
2004 through 2012; estimated totals have increased from about 9.9
million in 2004, to about 12.5 million in 2012. The average for the
years 2004 to 2012 was about 11 million units in use. Table 8 also
presents estimates of the numbers of portable generators in use by
ranges of kW ratings. These estimates were based on (1) portable
generator shipment and purchase data provided by PSR and Synovate for
the years 2004 through 2013, augmented by estimates of annual sales
developed for some individual manufacturers; and (2) estimates of
aggregate annual sales for prior years, in combination with Synovate
estimates of market shares for the various power categories for
previous years. The PPM was then used to estimate the product
population for each power category, assuming an 11-year average product
life. According to the population estimates, the largest power category
was generators 5 to 6.49 kW, accounting for an average of 3.6 million
units in use, or about 33 percent of the total, followed by generators
3.5 to 4.99 kW (averaging about 2 million units and 18.2% of the
total).
[GRAPHIC] [TIFF OMITTED] TP21NO16.011
Note that the estimates provided in Table 8 assume uniform expected
product lives across engine sizes and power ratings; that is, the
generators with smaller engine sizes are assumed to last as long as the
larger engine sizes. Larger engines usually are rated for more hours of
operation than smaller engines. Assuming the hour ratings reflect the
relative differences in total hours of actual use, our estimates imply
fewer hours of use per year for smaller generators versus larger units
over their useful lives. This issue is addressed in the sensitivity
analysis, and information regarding product lives of units and average
annual hours of operation
[[Page 83588]]
would be welcome from industry and the public.
The proposed rule specifies different requirements for CO emission
rates depending on generator engine class and other objective
characteristics, rather than engine or generator power ratings. The
Directorate for Economic Analysis has estimated historical sales of
generators by engine class from estimated sales by kW ratings using
data from PSR reporting both generator power and engine displacement.
Table 9 presents estimated units in use for 2004 to 2012, by engine
class. Based on our analysis, the proportion of generators with smaller
engines (handheld and Class I) has increased over the 9-year period.
This is consistent with estimates of the increasing share of generators
in use with power ratings of under 3.5 kW, shown in Table 8, which
follows from the information presented regarding the apparent shift in
the U.S. market towards smaller, less powerful units.
[GRAPHIC] [TIFF OMITTED] TP21NO16.012
E. Benefit--Cost Analysis
This section of the analysis consists of a comparison of the
benefits and costs of the proposed rule. The analysis is conducted from
a societal perspective, considering all of the significant costs and
health outcomes. Benefits and costs are calculated on a per-product-in-
use basis. The benefits are based on the reduced risk of fatal and
nonfatal injury due to CO poisoning involving portable generators. The
costs are defined as the added costs of making the portable generators
comply with the proposed rule.
Our primary outcome measure is the expected net benefits (i.e.,
benefits minus costs) of the proposed rule. As noted above, our primary
analysis calculates the benefits and costs of the rule on a per-
product-in-use basis. However, aggregated estimates of the benefits and
cost on an annual basis can be readily calculated, given projections of
annual generator sales.
1. Societal Costs of Portable Generator Deaths and Injuries
As discussed in Section III, the Directorate for Epidemiology,
Division of Hazard Analysis (EPHA) reports that there were 659 deaths
involving portable generators from 2004 to 2012, an average of about 73
annually.\93\ The average annual societal costs of these CO deaths are
estimated to be about $637 million in 2014 dollars, based on a value of
a statistical life (VSL) of $8.7 million.\94\
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\93\ Tab A of staff's briefing package.
\94\ The estimated value of a statistical life (VSL) of $8.7
million (in 2014 dollars) is a revision of the VSL estimated by the
U.S. Environmental Protection Agency and is generally consistent
with other estimates based on willingness-to-pay. Kneiser et al.
(2012), suggested that a reasonable range of values for VSL was
between $4 million and $10 million (in 2001 dollars), or about $5.3
million to $13.3 million in 2014 dollars (BLS 2015).
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[[Page 83589]]
EPHA also provided an estimate of CO-related injuries involving
portable generators, based on estimates from the National Electronic
Injury Surveillance System (NEISS) during the years 2004 through
2012.\95\ According to EP, there was a minimum of 8,703 nonfatal CO
poisonings involving portable generators that were treated in hospital
emergency departments from 2004 through 2012, or a minimum of about 967
annually.\96\ This NEISS estimate is considered a minimum because the
estimate only included injuries that were explicitly attributed to CO
poisoning injuries in the NEISS narrative.
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\95\ Stephen Hanway, Division Director, Division of Hazard
Analysis, Directorate for Epidemiology, CPSC. Memorandum to Gregory
B. Rodgers, AED, Directorate for Economic Analysis, CPSC: ``Injuries
associated with generators seen in emergency departments with
narratives indicative of CO poisoning 2004-2012 for injury cost
modeling,'' October 6, 2015.
\96\ Tab H of staff's briefing package.
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The NEISS injury estimates are limited to individuals initially
treated in hospital emergency departments. However, the CPSC's Injury
Cost Model (ICM) uses empirical relationships between the
characteristics of injuries and victims in cases initially treated in
hospital emergency departments and those initially treated in other
medical settings (e.g., physicians' offices, ambulatory care centers,
emergency medical clinics), based primarily on data from the Medical
Expenditure Panel Survey,\97\ to estimate the number of medically
attended injuries that were treated outside of hospital emergency
departments. The ICM also analyzes data from the Nationwide Inpatient
Sample of the Healthcare Cost and Utilization Project \98\ to project
the number of direct hospital admissions bypassing the hospital
emergency departments. According to the ICM estimates, there were an
additional 16,660 medically attended injuries during 2004 to 2012, or
about 1,851 annually. Consequently, based on NEISS and ICM estimates,
there was a minimum of about 2,818 medically attended injuries (967 ED
+ 1,851 non-ED) treated annually during the 9-year period.
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\97\ The Medical Expenditure Panel Survey (MEPS) is a nationally
representative survey of the civilian non-institutionalized
population that quantifies individuals' use of health services and
corresponding medical expenditures. The MEPS is administered by the
Agency for Healthcare Research and Quality (AHRQ). The MEPS has been
collected continuously since 1999 and is the principal data set used
to monitor medical spending in the U.S.
\98\ The National (Nationwide) Inpatient Sample (NIS) is part of
a family of databases and software tools developed for the
Healthcare Cost and Utilization Project (HCUP). The NIS is the
largest publicly available all-payer inpatient health care database
in the United States, yielding national estimates of hospital
inpatient stays. HCUP is a family of health care databases and
related software tools and products developed through a Federal-
State-Industry partnership and sponsored by the Agency for
Healthcare Research and Quality (U.S. Department of Health & Human
Services).
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The ICM is fully integrated with NEISS and provides estimates of
the societal costs of injuries reported through NEISS, as well as the
costs associated with the estimated medically attended injuries treated
outside of hospital emergency departments. The major aggregated
societal cost components provided by the ICM include medical costs,
work losses, and the intangible costs associated with lost quality of
life or pain and suffering.
Medical costs include three categories of expenditures: (1) Medical
and hospital costs associated with treating the injury victim during
the initial recovery period and in the long run; the costs associated
with corrective surgery; the treatment of chronic injuries, and
rehabilitation services; (2) ancillary costs, such as costs for
prescriptions, medical equipment, and ambulance transport; and (3)
costs of health insurance claims processing. Cost estimates for these
expenditure categories were derived from a number of national and state
databases, including the Medical Expenditure Panel Survey, the
Nationwide Inpatient Sample of the Healthcare Cost and Utilization
Project, the Nationwide Emergency Department Sample,\99\ the National
Nursing Home Survey,\100\ MarketScan[supreg] \101\ claims data, and a
variety of other federal, state, and private data.
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\99\ The Nationwide Emergency Department Sample (NEDS) is part
of a family of databases and software tools developed for the
Healthcare Cost and Utilization Project (HCUP). The NEDS is the
largest all-payer emergency department (ED) database in the United
States, yielding national estimates of hospital-based ED visits.
\100\ The National Nursing Home Survey (NNHS) is a series of
nationally representative sample surveys of United States nursing
homes, their services, their staff, and their residents. The NNHS
was first conducted in 1973-1974 and repeated in 1977, 1985, 1995,
1997, 1999, and most recently in 2004.
\101\ The MarketScan[supreg] Commercial Claims and Encounters
(MarketScan) Database from Truven Health Analytics contains de-
identified, person-specific health data of reimbursed healthcare
claims for employees, retirees, and their dependents of more than
250 medium and large employers and health plans.
---------------------------------------------------------------------------
Work loss estimates are based on information from the Nationwide
Inpatient Sample of the Healthcare Cost and Utilization Project, the
Nationwide Emergency Department Sample, Detailed Claims Information (a
workers' compensation database), the National Health Interview Survey,
the U.S. Bureau of Labor Statistics and other sources. These estimates
include: (1) Forgone earnings of the victim, including lost wage work
and household work; (2) forgone earnings of parents and visitors,
including lost wage work and household work; (3) imputed long-term work
losses of the victim that would be associated with permanent
impairment; and (4) employer productivity losses, such as the costs
incurred when employers spend time juggling schedules or training
replacement workers.
Intangible, or noneconomic, costs of injury reflect the physical
and emotional trauma of injury, as well as the mental anguish of
victims and caregivers. Intangible costs are difficult to quantify
because they do not represent products or resources traded in the
marketplace. Nevertheless, they typically represent the largest
component of injury cost and need to be accounted for in any benefit-
cost analysis involving health outcomes.\102\ The ICM develops a
monetary estimate of these intangible costs from jury awards for pain
and suffering. Although these awards can vary widely on a case-by-case
basis, studies have shown them to be systematically related to a number
of factors, including economic losses, the type and severity of injury,
and the age of the victim (Viscusi, 1988; Rodgers, 1993).\103\
Estimates for the ICM were derived from regression analysis of jury
awards compiled by Jury Verdicts Research, Inc., for nonfatal product
liability cases involving consumer products.
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\102\ Rice, D., MacKenzie, E. & Associates (1989). Cost of
injury in the United States: A report to Congress. San Francisco,
CA: Institute for Health & Aging, University of California and
Injury Prevention Center, The Johns Hopkins University.
\103\ Viscusi, W.K. (1988). The determinants of the disposition
of product liability cases: Systematic compensation or capricious
awards? International Review of Law and Economics, 8, 203-220;
Rodgers, G. (1993). Estimating jury compensation for pain and
suffering in product liability cases involving nonfatal personal
injury. Journal of Forensic Economics 6[euro], 251-262.
---------------------------------------------------------------------------
According to the ICM, the estimated injury costs of the
approximately 2,817 medically attended portable generator CO injuries
annually amounted to about $184 million (in 2014 dollars), an estimated
average of $65,400 per injury. Medical costs and work losses accounted
for about 53 percent of the total, while the non-economic losses
associated with pain and suffering accounted for about 47 percent. The
societal costs of both fatal and nonfatal CO poisoning injuries
involving portable generators amounted to about $821 million ($637
million for fatal
[[Page 83590]]
injuries + $184 million for nonfatal injuries) annually.
The average annual societal cost estimates for generators in use in
2004 through 2012, by engine class, are presented in more detail in
Table 10. Row 1 provides the annual estimates of fatal CO poisoning
injuries by engine class, and the estimated percent of all deaths
involving each category. Note that information on engine class for
generators involved in the deaths was available on only about 48
percent of the cases. The cases in which the engine classes were not
known were distributed proportionally to the cases in which the classes
were known.
Row 2 shows estimated annual nonfatal injuries by engine class; the
nonfatal CO injuries were distributed proportionally to the deaths
because very little information is available on the displacement of
engines of generators involved in these injuries. Row 3 provides
estimates of the aggregate annual societal costs of the deaths and
injuries. Societal costs were based on a VSL of $8.7 million per death,
and the nonfatal injury costs are from the ICM modeling. Row 4 provides
the annual estimates of portable generators in use by engine class, as
well as the estimated percent of all units in use for each category.
Row 5 provides annual per-unit societal costs of deaths and injuries,
which is based on the Row 3 estimates divided by the estimated numbers
of portable generators in use (shown in Row 4).
[GRAPHIC] [TIFF OMITTED] TP21NO16.013
Finally, Row 6 provides per-unit estimates of the present value of
the expected societal costs (at a 3% discount rate) over the expected
product life of a generator. This figure is useful in benefit-cost
analysis because it represents the maximum per-unit benefits that might
be derived from a product safety standard, if the standard prevented
all deaths and injuries. The present value of expected societal costs
is $687 per unit for portable generators with handheld engines (which
are estimated to have accounted for less than 1% of units in use during
the period 2004 through 2012); $672 per unit for generators with Class
I engines (35.5% of units in use); $758 per unit for generators with
one-cylinder Class II engines (56.7% of units in use); and $116 per
unit for generators with two-cylinder Class II engines (7.1% of units
in use). The societal costs associated with the two-cylinder Class II
generators are substantially lower than for the other generator
categories because of the small relative risk for the two-cylinder
models. Because the two-cylinder models accounted for about 7.1 percent
of generators in use, but only about 1.2 percent of the deaths, the
risk of death with two-cylinder generators was only about 16 percent of
the risk associated with generators with one-cylinder engines (i.e.,
handheld, Class I, and one-cylinder Class II generators). The average
expected present value of societal costs of CO poisoning deaths and
injuries for all portable generators is $682 per unit. These
calculations also represent baseline estimates of the societal costs
associated with portable generators, by engine class and other
characteristics: Estimates of what per-unit societal costs would be in
the absence of regulatory action. Benefits of the proposed rule can,
therefore, be estimated as the expected reduction in the baseline
societal costs.
2. Estimated Benefits of the Proposed Rule
As described in Section IX, the requirements of the proposed
performance standard require portable generators powered by handheld
engines and Class I engines to emit CO at a weighted rate that is no
more than 75 grams per hour (g/hr); generators powered by one-cylinder
Class II engines to emit CO at a weighted rate that is no more than 150
g/hr; and generators powered by two-cylinder Class II engines to emit
CO at a weighted rate that is no more than 300 g/hr. As noted in CPSC
staff's analysis that provides the rationale for the performance
requirements, considering expected manufacturing variability of 50 percent, based on limited testing of
[[Page 83591]]
pairs of generators, as described in the staff's briefing package,
these emission requirements reflect a factor of 1.5 over the expected
technically feasible emission rates for each engine classification: 50
g/h for those with handheld and Class I engines; 100 g/h for those with
one-cylinder Class II engines; and 200 g/h for those with two-cylinder
Class II engines.\104\ Comments and additional data on expected
manufacturing variability would be welcome, given the limited data
available to staff to evaluate variability.
---------------------------------------------------------------------------
\104\ Tab I of staff's briefing package.
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To estimate the expected reduction in societal costs, and hence,
the benefits from the proposed rule for portable generators, an
interdisciplinary analysis by CPSC staff provided estimates of
generator-related consumer CO poisoning deaths reported in the agency's
databases that could have been avoided as a result of reduced CO
emission rates from generators. An important part of the analysis was
indoor air quality modeling by NIST under an interagency agreement to
estimate the transport of CO emitted from generators and predicted
health effects for scenarios and house characteristics found in CPSC's
incident data. CPSC staff then compared the health effects resulting
from emission rates from current generators to a range of lower CO
emission rates to estimate deaths that could have been avoided for each
emission rate.\105\
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\105\ See Tab K of staff's briefing package.
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The NIST modeling and CPSC staff analysis considered scenarios
associated with 503 CO poisoning deaths over 2004 to 2012, or about 76
percent of the 659 CO poisoning deaths in CPSC records over the 9-year
period. These deaths occurred at various fixed-structure residential
settings, including traditional houses, mobile homes, townhomes, and
structures attached to a home, in addition to residential sites where
generators were operated in separate structures, such as sheds cabins
used for temporary (non-residential) shelter and detached garages. For
the purposes of this analysis, deaths and injuries occurring in these
settings are considered to be those that would be which would be
addressable by the proposed rule. However, we note that an unquantified
number of the 156 deaths not modeled by NIST might be addressed and
prevented by the proposed rule.\106\
---------------------------------------------------------------------------
\106\ IBID.
---------------------------------------------------------------------------
Chart 3 presents the results of CPSC staff analyses of estimated
reductions in CO poisoning fatalities that would result from lower-
weighted emission rates for modeled scenarios under various weighted CO
emission rates. At each reduced emission rate, the estimated percentage
reduction in fatalities is greater for generators powered with larger
engines because of their higher average estimated base rate for CO
emissions (4700 g/h for one-cylinder and 9100 g/h for two-cylinder
Class II engines vs 1800 g/h for Class I non-handheld engines and 900
g/h for handheld engines).\107\ In CPSC engineering staff's judgment,
the technically feasible weighted CO emission rates are 50 g/h for
generators powered by handheld and Class I engines, 100 g/h for
generators powered by one-cylinder Class II engines, and 200 g/h for
generators with two-cylinder Class II engines.\108\
---------------------------------------------------------------------------
\107\ These rates assume a factor of 3 in the increase in CO
emission rate of a generator operating in an enclosed space compared
to operation outdoors in normal oxygen. This factor of 3 is based on
testing of carbureted generators conducted by NIST (Emmerich,
Polidoro & Dols, op. cit.) and CPSC staff (Brookman, 2016, TAB J of
the NPR Briefing Package).
\108\ See Tab I of staff's briefing package.
---------------------------------------------------------------------------
Emission rates from generators meeting the proposed performance
requirements are expected to be higher while operating indoors (at
reduced oxygen levels of approximately 17%) than the feasible rates
under conditions of approximately 20.9% oxygen: Perhaps 150 g/h for
generators with handheld engines and Class I engines, 300 g/h for
generators with one-cylinder Class II engines and 600 g/h for
generators with two-cylinder Class II engines (three times the
technically feasible rate for each generator category).\109\ Based on
staff's analysis of 503 deaths (76 percent of all deaths) modeled by
NIST (and generally deemed to be addressable by the proposed standard),
these emission rates are expected to result in about a 47 percent
reduction in (addressable) fatalities involving generators with
handheld engines; about a 49 percent reduction in fatalities involving
generators with Class I engines; a 37 percent reduction for those with
one-cylinder Class II engines: And a reduction of about 17 percent for
generators with two-cylinder Class II engines. The average expected
reduction in CO poisoning fatalities across generators of all engine
types is about 44 percent of the addressable deaths and injuries, or
about 33 percent of all generator-related deaths and injuries (44% x
76%).
---------------------------------------------------------------------------
\109\ Based on CPSC's testing of three generators with fuel-
injected engines having different degrees of closed-loop operation
(see TAB J of staff's briefing package), CPSC believes the factor of
increase when the oxygen is 17 percent may be less than 3 for some
generators that use closed-loop EFI. Furthermore, test results from
NIST (Buyer, 2012) indicate the prototype EFI generator depleted the
oxygen significantly less than the carbureted generator, when tested
in each of four matched-pair identical test scenarios. Nevertheless,
CPSC assumes in the benefits analysis a conservative factor of 3 for
the increase in CO emissions for low-emission generators when
operating at reduce oxygen levels of 17 percent. Therefore, the
factor of 3 likely overstates the weighted CO emission rates for EFI
generators when operated indoors, and understates the reduction in
deaths and injuries resulting from the draft standard.
---------------------------------------------------------------------------
[[Page 83592]]
[GRAPHIC] [TIFF OMITTED] TP21NO16.014
Table 11 presents estimated reductions in societal costs, and
hence, benefits of the reduced CO emissions predicted to result from
the proposed standard. The per-unit societal costs per generator, from
Table 10, are included at row 1. However, as noted above, not all of
these costs would be addressed by the proposed standard or were not
included among the major residential scenarios modeled by NIST.\110\
The present value of expected societal costs of CO poisoning that would
be addressed by an emission standard are shown in row 2 and average
about $514 for generators with Class I engines and about $586 for
generators with one-cylinder Class II engines--engine categories that
combine for an estimated 92 percent of portable generators in use.
Generators with handheld engines, estimated to account for less than 1
percent of units in use, are estimated to average $525 in societal
costs. Generators with two-cylinder Class II engines are estimated to
average $26 in societal costs of CO poisoning over their useful lives.
These larger generators are estimated to account for about 7 percent of
all units in use.
---------------------------------------------------------------------------
\110\ About 76 percent of all CO poisoning deaths from 2004 to
2012 involved scenarios that were modeled by NIST. Among the
scenarios that were not modeled are those involving CO poisoning
deaths in apartments, vehicles and trailers (non-mobile homes), and
other structures, such as a church, a sea-land container, and tents.
---------------------------------------------------------------------------
Row 3 shows the staff's estimates of weighted CO emissions from
complying generators of the different engine categories that would
result from operation in conditions of reduced oxygen. Row 4 shows the
estimated reduction in addressable societal costs resulting from the
weighted emission rates, based on CPSC staff's estimate of the
reduction in CO poisoning deaths.\111\ Our estimate of reduction in
societal costs of CO poisoning deaths and injuries assumes that
projected injury costs from annual production of generators will fall
in proportion to estimated death reduction, with a minor adjustment to
account for the possibility that deaths avoided by reduced CO emissions
would still occur as injuries.\112\ With projected reductions in deaths
and injuries under the proposed standard, the present value of benefits
(shown in row 5 of Table 10) is estimated to average about $243 for
generators with handheld engines; $254 per unit for generators with
Class I engines; $214 per unit for generators with one-cylinder Class
II engines; and $4 for generators with two-cylinder Class II engines.
Average projected present value of benefits for all portable generators
is about $227 per unit.
---------------------------------------------------------------------------
\111\ Tab K of the staff's briefing package.
\112\ We have assumed that avoided deaths under the proposed
rule would still occur as nonfatal CO injuries of average severity
and cost.
---------------------------------------------------------------------------
Multiplying the present value of expected benefits per unit by
estimated annual unit sales (in row 6) yields the estimated aggregate
present value of benefits from annual sales of portable generators that
would comply with the proposed standard. The estimated present value of
benefits of reduced CO poisoning from complying portable generators
sold in a year totals about $315 million. Nearly 99 percent of the
total benefits are attributable to expected sales of generators with
Class I engines and one-cylinder Class II engines. These two types of
engines are expected to comprise about 94 percent of annual unit sales
under the proposed standard.
[[Page 83593]]
[GRAPHIC] [TIFF OMITTED] TP21NO16.015
Projections of benefits of the proposed rule should account for
recent changes, and reasonably expected changes, in the market that
will affect societal costs and the costs of compliance by
manufacturers. One consideration that would be expected to reduce the
addressable societal costs of the rule from those estimated for the
period of 2004 to 2012 is the relatively recent introduction of units
with EFI. Increased use of EFI would also reduce the costs of
compliance with a standard based on reduced CO emissions. However,
portable generators with EFI have not yet gained a significant share of
the consumer market for portable generators, and we have little basis
for incorporating projected sales of EFI units into the analysis.
Regarding the introduction of EFI on expected hazard costs, most of the
EFI-equipped portable generators have reportedly not targeted
reductions in CO emissions, specifically. Therefore, a relatively small
share of the generator market would not be expected to contribute to
substantial reduction in the overall hazard. However, costs of
compliance with a mandatory standard would be greatly reduced for units
with EFI systems.
In addition to reducing societal costs related to CO poisoning
deaths and injuries, product modifications to achieve greatly reduced
CO emissions could also result in improved fuel efficiency and other
benefits, including easier starting, altitude compensation, fuel
adaptability, improved power, better reliability and longer useful
product life.
3. Estimated Costs of Compliance With the Proposed Rule
a. Costs of Compliance per Unit
Based on the judgment of CPSC engineering sciences staff, the most
likely technical means of compliance with the requirements of the
proposed rule would be the use of closed-loop electronic fuel-injection
systems to achieve and maintain the needed air-to-fuel ratios under
different loads and ambient conditions.\113\ Another element expected
to be part of the industry's technical response to the proposed
standard is the addition of 3-way catalysts in the muffler systems of
portable generator engines. Besides achieving further reductions in CO
emissions, these catalysts would likely serve to reduce HC and
NOX emissions for continued compliance with EPA emission
standards for small spark-ignition engines.
---------------------------------------------------------------------------
\113\ Janet L. Buyer, Technology Demonstration of a Prototype
Low Carbon Monoxide Emission Portable Generator. U.S. Consumer
Product Safety Commission, Bethesda, MD. September 2012.
---------------------------------------------------------------------------
More detailed discussions of the expected product modifications,
and other factors leading to cost increases, appear in the following
discussion. All cost estimates are expressed in 2014 dollars, for
comparison with estimated benefits of the proposed rule.\114\
---------------------------------------------------------------------------
\114\ Cost estimates are adjusted to 2014 dollars by applying
changes in the producer price index for riding lawn & garden
equipment, a product group with similarities to portable generators.
---------------------------------------------------------------------------
(1.) Electronic Fuel Injection (EFI)
The likely industry switch from engines with carburetors as the
means of fuel delivery to closed-loop EFI is expected to be the most
significant factor in determining cost increases under the proposed
rule. This technology has been used for a number of years on the small
spark-ignition engines in small motorcycles and scooters, as well as in
more recent years in a variety of other product applications, including
lawnmowers/tractors and golf carts. Although some firms have introduced
portable generators with EFI for the consumer market in the last couple
of years, generators with this fuel delivery system currently account
for a very small fraction of sales. Associated components for closed-
loop EFI could include the electronic control unit, fuel pump,
injector(s), pressure regulator, throttle body, and a variety of
sensors, such as
[[Page 83594]]
manifold air pressure sensor or throttle position sensor, intake air
temperature sensor, oil temperature sensor, crank position sensor, and
related wiring and hardware, and an oxygen sensor for closed-loop
feedback. According to the EPA, the combined costs of these elements
for one-cylinder engines (which dominate the market for residential
generators) are estimated to be about $90 per unit in 2014
dollars.\115\ Cost savings of about $20 per unit are estimated for
elimination of the carburetor, yielding estimated net costs of about
$70 for the EFI components.
---------------------------------------------------------------------------
\115\ U.S. Environmental Protection Agency (EPA), (2006, July).
Small SI engine technologies and costs, final report. Prepared by
Louis Browning and Seth Hartley, ICF International, for the
Assessment and Standards Division, Office of Transportation and Air
Quality, EPA. Washington, DC. These cost estimates include original
equipment manufacturer markups and warranty markups totaling an
estimated 34 percent; such markups were also included in EPA's cost
estimates.
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The effectiveness of EFI in controlling the air-fuel ratio with
resulting improved engine combustion efficiency and reduced CO
emissions was demonstrated by CPSC staff's technology demonstration
project,\116\ as well as by the EPA.\117\ The EPA's demonstration work,
which formed the basis of their 2008 analysis of more stringent
requirements for HC and NOX emissions of small non-road
spark-ignition engines, provides a basis for our evaluation of this
technology, specific to portable generators. The EPA estimates are
largely consistent with other confidential estimates of costs provided
by manufacturers of generators, as well as by a manufacturer of fuel-
control components during discussions with CPSC staff.
---------------------------------------------------------------------------
\116\ Janet L. Buyer, Technology Demonstration of a Prototype
Low Carbon Monoxide Emission Portable Generator. U.S. Consumer
Product Safety Commission, Bethesda, MD. September 2012.
\117\ McDonald, Joseph, Olson B, and Murawski M, Demonstration
of Advanced Emission Controls for Nonroad SI Class II Engines, SAE
paper 2009-01-1899.
---------------------------------------------------------------------------
Most CO poisoning deaths from portable generators occur when
generators are used in enclosed spaces, such as in a closed garage,
basement, or room in the living space of a house, or in a partially
enclosed space, such as in a garage with the garage door opened part
way.\118\ In such scenarios, the spark-ignition engines are likely to
be operating in conditions of decreasing oxygen concentrations in the
ambient air. As noted previously, these conditions can make combustion
less efficient, thereby increasing CO emission rates as the generators
continue to operate, unless the reduced oxygen level is taken into
account. CPSC's benefits analysis takes this into consideration by
noting that both carbureted and closed-loop fuel-injected generators'
CO emission rates increase as the oxygen in the intake air to the
generator decreases.\119\ In CPSC staff's view, compliance with these
performance requirements would likely require the use of an oxygen
sensor placed in the engine's exhaust stream to provide closed-loop
feedback to the fuel-control system. The oxygen sensor sends a voltage
signal to the electronic control unit that varies with the amount of
oxygen in the engine exhaust. The ECU uses this signal to check that
the correct amount of fuel is being metered through the fuel injector
to maintain the air/fuel ratio at or near stoichiometry, which is the
theoretical point for near-complete combustion and minimized CO
emissions. The ECU uses the other sensors to determine how much fuel to
provide, and the oxygen sensor provides feedback on whether or not the
fuel mixture is correct. In this closed-loop operation, the ECU would
continually adjust the fuel mixture to maintain complying CO emission
rates. Based on information developed for EPA when its staff considered
more stringent requirements for HC and NOX emissions, engine
manufacturers that incorporate oxygen sensors in the exhaust streams of
portable generator engines could incur variable costs of about $10 per
engine (adjusted to 2014 dollars).\120\
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\118\ Tab A of the staff's briefing package.
\119\ See Tabs I and K of the staff's briefing package.
\120\ U.S. Environmental Protection Agency (EPA) (2008,
September). Control of emissions from marine SI and small SI
engines, vessels, and equipment: Final regulatory impact analysis.
Assessment and Standards Division, Office of Transportation and Air
Quality. Washington, DC. Page 6-22; As with EFI cost estimates, this
per-unit cost estimate related to oxygen sensors includes original
equipment manufacturer and warranty markups totaling 34 percent.
---------------------------------------------------------------------------
In its assessment of costs of this feature for small spark-ignition
engines, the EPA (2006) also projected that Class I engines would also
require batteries and alternators/regulators at estimated additional
costs totaling about $17 (including original equipment manufacturer and
warranty markups). As previously noted, data on shipments of portable
generators for 2010 through 2014 show that portable generators with
Class I engines comprised about 59 percent of units shipped, and those
with Class II engines accounted for about 41 percent of units.
Therefore, the estimated cost increase per unit for the EFI-related
components identified in this section would be about $94 for generators
with Class I engines (55% of units); about $79 for generators with one-
cylinder Class II engines (about 36%); and about $85 for generators
with two-cylinder Class II engines.\121\
---------------------------------------------------------------------------
\121\ Two-cylinder engines would require two fuel injectors,
which increases costs versus one-cylinder Class II engines.
---------------------------------------------------------------------------
We note that it may be technically feasible, and perhaps eventually
less costly for manufacturers to incorporate EFI systems that power-up
the fuel pump and electronic components by magnets when starter cords
are pulled. Battery-less EFI systems have been available in consumer
products for several years, including snowmobiles, outboard motors, and
motorcycles. However, we are not aware of the current use of this
technology in applications with Class I engines. Comments on
prospective use (e.g., costs, applicability and challenges) of battery-
less EFI for portable generators would be welcome.
(2.) Catalysts in Mufflers
Generator manufacturers also are likely to include three-way
catalysts \122\ in the mufflers of generator engines to achieve the low
CO emission rates that would be required by the proposed standard, and
still allow compliance with EPA Phase 3 emissions standards for other
pollutants in ES staff's judgment.\123\ Catalysts assist in chemical
reactions to convert harmful components of the engine's exhaust stream
(Hydrocarbons [HC] and oxides of nitrogen [NOX] in addition
to CO) to harmless gases. According to the Manufacturers of Emission
Controls Association (MECA), the catalysts perform this function
without being changed or consumed by the reactions that take place. In
particular, when installed in the exhaust stream, the catalyst promotes
the reaction of HC and CO with oxygen to form carbon dioxide and water,
and the chemical reduction of NOX to nitrogen is caused by
reaction with CO over a suitable catalyst.\124\
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\122\ Three-way catalysts are designed to simultaneously convert
three pollutants to harmless emissions: Carbon Monoxide [rarr]
Carbon Dioxide; Hydrocarbons [rarr] Water, and; Oxides of Nitrogen
[rarr] Nitrogen.
\123\ Tab I of staff's briefing package.
\124\ Manufacturers of Emission Controls Association (MECA)
(2009, January). White Paper: Emission control of small spark-
ignited off-road engines and equipment. Washington, DC. Retrieved
from: http://www.meca.org/galleries/files/sore_white_paper_0109_final.pdf.
---------------------------------------------------------------------------
In its assessment of the costs of the Phase 3 emission standards
for small SI engines, EPA estimated that 3-way catalysts in mufflers of
one-cylinder engines of portable generators could add about $10 to $20
in additional hardware costs to the manufacturing costs per engine,
depending on capacity, power, and useful life.\125\ These estimates
were
[[Page 83595]]
based on assumptions regarding use of precious metals (principally
platinum and rhodium), which were not formulated to oxidize CO, and
their prices in 2005. Based on our analysis of costs, including heat
shields or double-walled mufflers that could be necessary, catalytic
mufflers could add about $14 to the manufacturing cost of a Class I
engine and about $19 to the cost of a Class II engine. These costs
could vary, depending on choices and assumed loadings of precious
metals. Recent evaluations of nonprecious metal catalysts by MECA have
found that these less-costly catalysts perform well in the oxidization
of CO.\126\ Application of this technology could lead to a reduction in
costs of compliance related to catalytic after-treatment.
---------------------------------------------------------------------------
\125\ EPA, op. cit.
\126\ Kevin Hallstrom. ``Catalyst control of CO from portable
generators.'' Presentation on behalf of Manufacturers of Emission
Controls Association (MECA) at the PGMA Technical Summit, March 17,
2016. Available online (pp. 125-141) at: http://www.cpsc.gov//Global/Newsroom/FOIA/Meeting%20Logs/2016/MeetingLogPGMA31716.pdf.
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Although EPA assumed that Class I and Class II engines would
include catalytic mufflers under Phase 3 emission requirements, a
majority of small SI engines submitted for EPA certification in recent
years has not included after-treatment devices, such as catalysts.
Current engines produced with catalytic after-treatment would incur
smaller costs for this feature. In the view of CPSC engineering staff,
portable generators powered by 4-stroke handheld engines might not
require catalysts to comply with the proposed rule since the catalyst
in both CPSC's and EPA's demonstration programs was primarily for
NOX reduction, and handheld engines have less stringent
NOX emission requirements under EPA emission standards.\127\
For purposes of estimating costs, we assume that catalyst-related costs
for generators with handheld engines would average 50 percent of
estimated costs for units with Class I engines, or about $7 per
generator.
---------------------------------------------------------------------------
\127\ Tab I of staff's briefing package.
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(3.) Design and Development/Other Reengineering
In an analysis of small SI engine technologies and costs, ICF
International estimated that costs of conversion to EFI from
carburetors would require 4 months of design time (engineers) and 6
months for development (by engineers and technicians) for Class I
engines and 2 months for design and 2 months for development for Class
II engines).\128\ Based on estimated labor costs for engineering/
technical staff, EPA estimated that these design and development costs
totaled about $175,000 for Class I engines and about $64,000 for Class
II engines, for each engine family. Design and development costs for
three-way catalysts in mufflers were estimated by EPA to be about
$135,000 per engine line for 2 months of design time (engineers) and 5
months of development time (engineers and technicians). Adjusting for
changes in an appropriate producer price index, the total design and
development costs for engines to incorporate EFI and catalysts are
estimated to be about $316,000 for a Class I engine family and $203,000
for a Class II engine family. We assume (as EPA did) that these costs
are recovered over 5 years. If average annual production per-engine
family ranges from 10,000 to 50,000 units, per-unit design and
development costs could range from about $1 to $6 for Class I engines
and under $1 to about $4 for Class II engines.
---------------------------------------------------------------------------
\128\ EPA (2006), op. cit.
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These estimated costs could be applicable for portable generator
manufacturers that supply their own engines. Engine manufacturers that
supply engines to independent generator manufacturers might
successfully pass along research and development costs with markups.
EPA estimated that manufacturing and warranty markups by suppliers of
EFI and catalytic components total 34 percent. Similar markups of
design and development costs by suppliers of complying engines could
increase generator manufacturing costs by about $2 to $8 for generators
with Class I engines and by about $3 to $5 for generators with Class II
engines. Manufacturers of approximately 80 percent of generators supply
their own engines. Therefore, average generator manufacturing costs for
design and development could be about $4.05 for generators with Class I
engines and $2.60 for generators with Class II engines.\129\
---------------------------------------------------------------------------
\129\ Midpoint estimates for annual engine family production
ranging from 10,000 to 50,000 units.
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Costs of design and development for generators powered by handheld
engines were not specifically addressed by EPA. For the purposes of
this preliminary analysis, we assume that these costs will be similar
to those estimated for units with Class I engines. However, we assume
that costs per engine family would be apportioned over perhaps 5,000 to
10,000 units annually. This assumption leads to average generator
manufacturing costs for design and development of about $10 per unit
for generators with handheld engines. We also acknowledge that models
with handheld engines often are valued and promoted for their
compactness and light weight. Accommodating new features that might be
necessary for compliance with the proposed rule and still provide these
desired product characteristics could present greater challenges and
costs for product engineers and firms. The Commission welcomes comments
on this issue, as well as on components and technologies that might be
available to meet these challenges and moderate the impacts of the
proposed rule on these models.
Costs of new designs and tooling may also be required for generator
frames and housings to accommodate additional components, such as
batteries for generators with Class I engines, and to address reported
concerns with heat dissipation. Modifications could be minimal for many
larger generators with open-frame designs; but some smaller units with
housings that enclose engines and other components could require
larger, redesigned housings, at greater cost. We have assumed that per-
unit tooling costs for generators with handheld engines would be twice
that of other generators, but costs may be underestimated for small
generators. The Commission welcomes comments on this issue from firms
that would be affected by the rule.
The modifications to small SI engines to comply with the CO
emission requirements of the CPSC standard would likely require engine
manufacturers to seek certifications (as new engine families) under EPA
requirements for HC+NOX and CO, with the attendant costs for
fees and testing, which could be passed on to generator manufacturers
that purchase the engines to power their products. Some of the larger
manufacturers of portable generators are vertically integrated firms
that also manufacture the engines that power their products. It is
possible that engine modifications by engine manufacturers (including
firms that also manufacture generators) to comply with the CPSC
emission standards for CO could result in emissions of
HC+NOX that are consistently lower than the EPA emission
requirements. This potential effect of the use of EFI and catalysts was
shown by demonstration programs sponsored by CPSC (conducted by the
University of Alabama) and EPA, as detailed in the CPSC staff's
technical rationale for the proposed standard.\130\ Consistently lower
emission rates for HC+NOX could result in ``engine credits''
for engine families under EPA's
[[Page 83596]]
program for averaging, banking and trading (ABT) of emission credits.
If manufacturers of engines participate in the ABT program, they could
partially offset increased manufacturing costs of compliance with the
proposed CPSC standard, and some of these savings could moderate the
engine cost increases incurred by generator manufacturers that do not
make their own engines.
---------------------------------------------------------------------------
\130\ Tab I of the staff's briefing package.
---------------------------------------------------------------------------
(4.) Testing and Certification
The proposed rule does not prescribe a particular test that
manufacturers must use to assess compliance with the performance
requirements. Instead, the proposed rule includes the test procedure
and equipment that CPSC would use to assess compliance with the
applicable performance requirements of the standard.\131\ Manufacturers
need not use the particular test referenced by the proposed rule,
although whatever test is used must effectively assess compliance with
the standard. We have assigned minor costs per unit for this element in
Table 12, but we welcome comments on this issue.
---------------------------------------------------------------------------
\131\ i.e., Weighted CO emission rates emitted from the
generator when operating in normal oxygen: 75 g/h for generators
with handheld and Class I engines; 150 g/h for generators powered by
one-cylinder Class II engines; and 300 g/h for generators powered by
two-cylinder Class II engines.
---------------------------------------------------------------------------
b. Other Potential Costs
Evaluation of more stringent emission standards by the EPA found
that pressurized oil lubrication systems for engines would be among the
engine design changes. EPA's assessment of this engine feature is that
it results in ``enhanced performance and decreased emissions'' because
it allows better calibrations and improved cooling potential.\132\
Based on estimates made for EPA, variable costs for a pressurized oil
system would be about $19 for small spark-ignition engines that now
lack this feature. In the view of the Directorate for Engineering
Sciences, pressurized lubrication systems would not be necessary to
comply with the draft standard. We welcome comments on this issue.
---------------------------------------------------------------------------
\132\ EPA (2006), op. cit.
---------------------------------------------------------------------------
c. Total Costs,per Unit
Aggregate estimated compliance costs to manufacturers of portable
generators average approximately $113 per unit for engine and muffler
modifications necessary to comply with the CO emission requirements of
the proposed standard. Cost elements by engine class and
characteristics are shown in Table 12.
[GRAPHIC] [TIFF OMITTED] TP21NO16.016
(1.) Implications for Retail Prices and Consumer Demand
In addition to the direct costs of the rule, increases in the
retail price of portable generators (as costs are passed forward to
consumers) are likely to reduce sales. Additionally, consumers who no
longer purchase portable generators because of the higher prices will
experience a loss in utility that is referred to as consumer surplus,
but is not included in the direct cost estimates described in the last
section. These impacts are illustrated conceptually in Chart 4 below.
For purposes of this analysis, we assume that cost increases are pushed
forward to consumers.
The downward sloping curve in Chart 4 represents the demand for
generators; p1 and q1 represent the preregulatory
price and quantity of generators demanded. After the regulation becomes
effective, generator prices rise to p2, and
[[Page 83597]]
the quantity of generators demanded declines to q2. The
value of p2 - p1 represents the direct costs of
the rule per generator (e.g., $113 for those with Class I engines and
$138 for two-cylinder Class II generators). The area given by the
rectangle a represents the aggregate annual direct costs of the rule,
which is equal to the product of the increase in portable generator
price (p2 - p1) and the post-regulatory quantity
demanded (i.e., q2). The triangle b represents additional
costs of the rule in the form of a loss in consumer surplus: A value
over and above what consumers paid for the product prior to the
regulation, but that is lost to the consumers who do not purchase a
generator at the higher price, p2.
[GRAPHIC] [TIFF OMITTED] TP21NO16.017
Given information on the pre-regulatory price (p1) and
quantity demanded (q1), the impact of the rule on product
prices, and information on the elasticity of demand for portable
generators (i.e., the percentage change in quantity demanded given a
percentage change in price), we can make an estimate of the expected
reduction in sales (q1 - q2), and the lost
consumer surplus represented by triangle b in Chart 4. Based on
information presented earlier, estimated preregulatory (current) sales
(i.e., q1) consist of about 15,000 generators with handheld
engines; about 801,000 generators with non-handheld Class I engines;
about 504,000 generators with one-cylinder Class II engines; and about
65,000 generators with two-cylinder Class II engines. Preregulatory
retail prices of portable generators (p1) average about $324
for generators with handheld engines; $534 for generators with non-
handheld Class I engines; $1,009 for generators with one-cylinder Class
II engines; and $2,550 for generators with two-cylinder Class II
engines.\133\
---------------------------------------------------------------------------
\133\ Based on an October 2015 survey of retail prices of more
than 350 portable generators as reported on Internet sites of six
retailers.
---------------------------------------------------------------------------
We are not aware of precise estimates of the price elasticity of
demand for portable generators; however, the nature of the product
could argue for a relatively inelastic demand: Sales of the product
often peak when consumers need or anticipate the need for backup power
for small and major appliances (e.g., during weather-related outages,
anticipated Y2K outages). In these circumstances price may not be a
significant determinant for many purchasing decisions. Based on
available estimates of the price elasticity of demand for household
appliances (for example: -0.23, by Houthakker & Taylor,\134\ and -0.35,
for refrigerators, clothes washers and dishwashers, by Dale & Fujita,
2008 \135\), the price elasticity for portable generators could be
approximately -0.3. If this relationship between price increase and
consumer demand holds true for complying portable generators marketed
under the proposed rule, a 1.0 percent increase in price for generators
would result in a 0.3 percent reduction in unit demand.
---------------------------------------------------------------------------
\134\ Houthakker, H.S. and Taylor, L. (2010). Consumer demand in
the United States: Analyses and projections, 2nd edition. Cambridge,
MA: Harvard University Press.
\135\ Dale, L. and Fugita, K.S. (2008, February). An analysis of
the price elasticity of demand for household appliances. Energy
Analysis Department, Environmental Energy Technologies Division,
Lawrence Berkeley National Laboratory, University of California.
Berkeley, CA.
---------------------------------------------------------------------------
Given these parameters, the quantity demanded might decline by
about 11 percent ($114/$324 x -0.3), on average, for generators with
handheld engines (reducing sales from about 15,000 to about 13,400
annually); by an average of about 6 percent ($113/$534 x -0.3) for
generators with non-handheld Class I engines (projected to reduce sales
from about 801,000 to about 750,000 annually); by about 3 percent
($110/$1,009 x -0.3) for generators with one-cylinder Class II engines
(projected to reduce sales from about 504,000 to about 487,000); and by
about 1 percent ($138/$2,550 x -0.3) for generators with two-cylinder
Class II engines
[[Page 83598]]
(projected to reduce sales from about 65,000 to 64,000). As noted in
our discussion of retail price information, factors other than engine
capacity or generator power affect retail prices; and lower-priced
generators with each engine class/category would be expected to face a
relatively greater price increase under the proposed rule, and
correspondingly, a greater decrease in consumer demand. In general, we
would anticipate that generators without features that increase price,
such as inverter technology, would realize a more significant
percentage impact on manufacturing costs, retail prices and consumer
demand, at least initially. Price increases for new generators that
would comply with the standard could lead more consumers to repair
their older units or to purchase used units on the secondary market.
Additionally, price increases for larger portable generators could lead
more consumers to purchase stationary, standby generators for use
during power outages.
The value of lost consumer surplus resulting from increased prices
under the proposed rule (represented by the area of triangle b in Chart
4) could be about $4 million annually; comprised of about $90,000 for
generators with handheld engines; $2.9 million for generators with
Class I engines; about $910,000 for generators with one-cylinder Class
II engines; and about $70,000 for generators with two-cylinder Class II
engines.
(2.) Combined Direct Costs and Lost Consumer Surplus per Unit
If the estimate of lost consumer surplus is spread over the
remaining units sold, the estimated costs, per product sold, might
average about $6.78 for generators with handheld engines ($91,000 /
13,400 units); $3.85 for generators with Class I engines ($2,889,000 /
750,000 units); $1.88 for generators with one-cylinder Class II engines
($914,000 / 487,000 units); and $1.14 for generators with two-cylinder
Class II engines ($73,000 / 64,000 units). If these per-unit costs of
lost consumer surplus are combined with the direct manufacturing costs
estimated previously in this section, the total estimated per-unit
costs would amount to about $121 for generators with handheld engines;
$117 for generators with Class I engines; $112 for generators with one-
cylinder Class II engines; and about $139 for generators with two-
cylinder Class II engines. These are the cost figures that will be
compared to the expected benefits of the rule.
It is possible, however, that some consumers might perceive greater
value for complying generators, in terms of fuel efficiency, greater
ease of starting, product quality and safety. These perceptions could
moderate the adverse impact on demand (i.e., reduced sales) resulting
from price increases.
1. Comparison of Benefits and Costs
Table 13 presents both the estimated benefits (Row 1) and the
estimated costs (Row 2) of the proposed rule. The expected per-unit
benefits were derived in Table 5; they average about $243 for
generators with handheld engines; $254 for generators with Class I
engines; $214 per unit for generators with one-cylinder Class II
engines, and; $4 for generators with two-cylinder Class II engines. The
estimated $4 in benefits for the two-cylinder Class II engines reflects
the fact that very few consumer deaths have involved these generators
in the scenarios modeled by NIST and analyzed by CPSC staff, perhaps
because they are less likely to be brought indoors because of their
size and weight or loudness during operation. Additionally, given the
limits on CO emissions for those generators, only about 17 percent of
the addressable societal costs are projected to be prevented by the
proposed rule.
The costs, including both manufacturing compliance costs (from
Table 12), and the costs associated with lost consumer surplus (from
the previous section), amount to $121 for generators with handheld
engines; $117 for generators with Class I engines; $112 for generators
with one-cylinder Class II engines; and about $139 for generators with
two-cylinder Class II engines.
As shown in Row 3, the proposed CO emission standard is estimated
to result in net benefits (i.e., benefits minus costs) of about $122
per unit for generators with handheld engines ($243-$121); $137 per
unit for generators with Class I engines ($254-$117); about $101 for
generators with one-cylinder Class II engines ($214-$112); and
approximately -$135 for generators with two-cylinder Class II engines
($4-$139).
Projected annual unit sales under the proposed standard are shown
in Row 4. Finally, Row 5 shows aggregate net benefits based on the
product of net benefits per unit (Row 3) and product unit sales (Row
4).
An examination of Row 5 indicates that aggregate net benefits would
be maximized at about $153 million annually, if only handheld engines,
Class I engines, and one-cylinder Class II engines are covered by the
proposed rule. Including the two-cylinder Class II engines under the
standard would reduce aggregate net benefits to about $145 million.
Rather, under the CPSA, the benefits of the rule must bear a reasonable
relationship to its costs, and the rule must impose the least
burdensome requirement that prevents or adequately reduces the risk of
injury. 15 U.S.C. 2058(f)(3)(E) and (F).
Hence, the preliminary regulatory economic analysis suggests that
excluding the portable generators with two-cylinder Class II engines
from the rule would maximize net benefits, an outcome that would be
consistent with OMB direction but not required under the CPSA.
Generators with these larger and more powerful engines accounted for
just 0.4 percent of the 503 consumer CO poisoning deaths addressed by
the simulation analysis performed by NIST and the benefits analysis
performed by CPSC staff (Hnatov, Inkster & Buyer, 2016). Portable
generators with two-cylinder engines are estimated to have comprised
about 7 percent of units in use over 2004 to 2012 (as shown in Tables 9
& 10) and about 5 percent of unit sales in recent years (Table 11).
[[Page 83599]]
[GRAPHIC] [TIFF OMITTED] TP21NO16.018
As discussed previously, the analysis was limited to the 503 out of
659 CO poisoning deaths during the period 2004 through 2012. Commission
staff reports that there could be some unquantified benefits associated
with 156 deaths not modeled by NIST.\136\ However, this would not
change the main findings of our analysis. If there were some additional
deaths involving generators with handheld, Class I, or one-cylinder
Class II engines that would have been prevented, our estimated net
benefits for these generator classes would increase somewhat. On the
other hand, even if all of the deaths involving generators with two-
cylinder Class II engines would have been prevented, the costs for this
class of generators would have exceeded the benefits.
---------------------------------------------------------------------------
\136\ See Tab K of the staff's briefing package.
---------------------------------------------------------------------------
Additionally, one underlying assumption for the benefits estimate
is that there would be no behavioral adaptations by consumers in
response to the reduced rate of CO emissions from portable generators.
Knowledge about reduced CO emissions from generators produced under the
proposed rule could reduce consumers' perceptions of injury likelihood
and susceptibility, which, in turn, could affect consumer
behavior.\137\ In economic terms, the proposed rule could reduce what
we might call the cost or risk-price of unsafe behavior, and implicitly
provide an incentive for consumers to increase that behavior. If
consumers are aware of the reduced CO poisoning risk, and the rule does
not make it more difficult to operate generators indoors, it seems
likely that there would be some increase in warned-against practices.
For example, some consumers might reduce the distance between their
house and the generator because they think closer proximity of the
generator to the house will reduce the likelihood that the generator
will be stolen. Similarly, to keep the generator out of the elements,
some consumers who had run their generator outside might decide to
bring it into the garage. Additionally, some consumers might even
decide to run the generator inside their home. Behavioral adaptation as
a potential effect of the rule is discussed by CPSC's Division of Human
Factors (HF) (Smith, T., 2016). We cannot quantify this impact, and for
reasons cited by HF, it could be small. However, while the proposed
rule will significantly increase the safety of generators from an
engineering standpoint, it seems likely that the increased technical
safety predicted by modeling under the assumption of no behavioral
adaptation will be partially be offset by the behavioral adaptations of
some users.
---------------------------------------------------------------------------
\137\ This potential effect of knowledge about improvements in
safety has been addressed in human factors literature, such as the
article by Leonard Evans in ``Human Behavior Feedback and Traffic
Safety,'' published in Human Factors: The Journal of the Human
Factors and Ergonomics Society, 27(5), 555-576. January 1985.
---------------------------------------------------------------------------
F. Sensitivity Analysis
The benefit-cost analysis presented above compares benefits and
costs of our base-case analysis. In this section, we present a
sensitivity analysis to evaluate the impact of variations in some of
the important parameters and assumptions used in the base-case
analysis. Alternative inputs for the sensitivity analysis included:
Shorter (8 years) and longer (15 years) expected product-
life estimates than the 11 years used in the base analysis;
A discount rate of 7 percent, rather than 3 percent, to
express societal costs and benefits in their present value;
Compliance costs and lost consumer surplus per-unit that
are 25 percent higher than the base analysis;
Lower ($5.3 million) and higher ($13.3 million) values of
a statistical life (VSL) than the $8.7 million value for the base
analysis; and
Lower (by 25%) and higher (by 25%) effectiveness for each
engine class and characteristic at reducing societal costs of CO
poisoning.
The results of the sensitivity analysis are presented in Table 14,
with Part A showing estimated net benefits per unit for generators in
our base-case analysis (from Table 13) for each engine class and type,
and Part B presenting the estimated net benefits per unit, using the
alternative input values.
Variations in the expected product life had a relatively small
impact on net benefits; a reduced expected product life decreased
expected net benefits slightly, while an increased expected product
life increased net benefits (rows a and b).
OMB (2003) recommends conducting a regulatory analysis using a 3
percent and 7 percent discount rate.\138\ Because
[[Page 83600]]
of the relatively long product life of generators, using a 7 percent
discount rate substantially reduced estimates of net benefits for the
first three generator categories, but they remained positive (row c).
However, because benefits were so small for the units with 2-cylinder
Class II engines, the impact of the 7 percent discount rate on this
category was negligible.
---------------------------------------------------------------------------
\138\ Our base analysis discount rate is consistent with
research suggesting that a real rate of 3 percent is an appropriate
discount rate for interventions involving public health (see Gold,
M., Siegel, J., Russell, L. and Weinstein, M., eds. (1996). Cost-
effectiveness in health and medicine. New York: Oxford University
Press); a 3 percent discount rate (along with a 7 percent discount
rate) is also recommended for regulatory analyses by the Office of
Management and Budget (OMB, 2003).
---------------------------------------------------------------------------
Variations in cost estimates would directly impact our estimates of
net benefits. Discussions with generator and engine manufacturers
suggest that the EPA cost estimates, upon which our analysis was based,
may have led to underestimates of the incremental costs of EFI and
other components that would be needed for the proposed rule. However,
the results of this sensitivity analysis show that even if we had
systematically underestimated the costs of the proposed rule by 50
percent, the findings of the analysis would have remained unaltered:
Generators with handheld, Class I, and one-cylinder Class II engines
would continue to exhibit positive net benefits.
Finally, we considered the impact of variations in the value of
statistical life (VSL) on the results of the analysis. Kniesner,
Viscusi, Wook and Ziliak (2012) suggested that a reasonable range of
values for VSL was between $4 and $10 million (in 2001 dollars),\139\
or about $5.3 million to $13.3 million in 2014 dollars. Consequently,
we evaluated the sensitivity of our results to variations in the VSL by
applying these alternative VSLs (rows e and f). This variation had a
substantial impact on the estimated net benefits (as would be expected
given deaths account for the great majority of generator-related
societal costs). Nevertheless, the variations in VSL did not affect the
results of the analysis.
---------------------------------------------------------------------------
\139\ Kneiser, Viscusi, Wook & Ziliak (2012). The value of a
statistical life: Evidence from panel data. The Review of Economics
and Statistics, 94(1), 74-87.
---------------------------------------------------------------------------
In summary, for each variation analyzed, the overall estimated net
benefits of the proposed standard were found to remain positive for the
first three categories of generators. However, as with the base-case
analysis, the sensitivity analysis showed that generators with two-
cylinder Class II engines had estimated costs that remained
substantially greater than the present value of projected benefits.
[GRAPHIC] [TIFF OMITTED] TP21NO16.019
[[Page 83601]]
[GRAPHIC] [TIFF OMITTED] TP21NO16.020
G. Regulatory Alternatives
In accordance with OMB (2003) guidelines to federal agencies on
preparation of regulatory impact analyses, the Commission considered
several regulatory alternatives available to the Commission that could
address the risks of CO poisoning from consumer use of portable
generators. The alternatives considered included: (1) Establishing
less-stringent (higher allowable) CO emission rates; (2) excluding
generators with Class II, two-cylinder engines from the scope of the
rule; (3) an option for reducing consumer exposure to CO by using an
automatic shutoff; (4) establishing later compliance dates; (5) relying
upon informational measures only; and (6) taking no action.
1. Less Stringent (Higher Allowable) CO Emission Rates
Cost savings from higher allowable CO emission rates might result
from lower costs associated with catalysts (if they would not be
required, or if less costly materials could suffice), less
[[Page 83602]]
extensive engine modifications (other than EFI-related costs) and less
extensive generator-housing modifications (if housing enlargement and
other retooling would be minimized). For example, CPSC staff's report
presenting the technical rationale for the proposed standard speculates
that 4-stroke handheld engines might not need a catalyst,\140\ and in
our base-case estimate of catalyst-related costs for generators with
handheld engines, we assumed an average of 50 percent of the estimated
costs for units with Class I engines, or about $7 per unit. A less
stringent emission standard could allow more units with handheld
engines, and perhaps some with smaller Class I engines, to comply
without catalytic after-treatment.
---------------------------------------------------------------------------
\140\ See Tab I of the staff's briefing package.
---------------------------------------------------------------------------
Expected reductions in societal costs from CO poisoning in
scenarios analyzed by the Commission could be about 30 percent for
units with handheld engines; about 36 percent for units with Class I
engines; about 30 percent for generators with 1-cylinder Class II
engines; and about 11 percent for generators with 2-cylinder Class II
engines. We estimate that these reductions in societal costs would be
reflected in decreased present value of benefits per unit of nearly $90
for generators with handheld engines (a decrease of 36%); about $70 for
generators with Class I engines (-28%); and about $40 for units with 1-
cylinder Class II engines (- 18%). It seems likely that cost savings
from less stringent CO emission requirements would be less than
expected reductions in benefits. Therefore, net benefits of the rule
would probably decrease under this regulatory alternative.
The Commission did not consider a more stringent alternative
because CPSC engineering staff believes that the rates in the proposed
rule are based on the lowest rates that are technically feasible.
Comments providing information on the benefits and costs that would be
associated with different CO emission rates would be welcome.
2. Alternative Scope: Limiting Coverage to One-Cylinder Engines,
Exempting Portable Generators With Two-Cylinder, Class II Engines From
the Proposed Rule
The Commission could exempt portable generators with two-cylinder
Class II engines from the requirements of the proposed rule. As shown
in the base-case analysis, the gross benefits that would be derived
from including this class of portable generators within the
requirements of the standard would only amount to about $4 per unit.
There are two reasons for the small per-unit benefit estimate. First,
while generators with two-cylinder Class II engines accounted for 7.1
percent of generators in use during the 2004 through 2012 study period,
they accounted for only about 1.2 percent of deaths. Consequently, the
relative risk for generators with two-cylinder Class II engines was
only about 16 percent of the risk for the handheld and one-cylinder
models. Second, the analysis of benefits of the proposed emission
limits for generators with two-cylinder Class II engines (300 g/hr at
unreduced ambient oxygen levels) suggests that the proposed rule would
only prevent about 17 percent of the addressable deaths for this class
of generators (Hnatov, Inkster & Buyer, 2016).\141\
---------------------------------------------------------------------------
\141\ See Tab K of the staff's briefing package.
---------------------------------------------------------------------------
The costs of the proposed rule are estimated to amount to $139 per
two-cylinder, Class II generator, yielding negative net benefits of
about $135 ($4 in benefits--$139 in costs) per unit. Given annual sales
of about 64,000 units, the aggregate net benefits associated with this
class of generators would amount to about -$8.6 million (64,000
generators x $135 per generator) annually. In other words, excluding
this class of generators from the requirements of the proposed rule
would increase the net benefits of the rule by about $8.6 million
annually, to approximately $153 million. We also note that the total
estimated value of expected societal costs of CO poisoning deaths and
injuries per unit, including those not addressed by the staff's
epidemiological benefits analysis, is $116 per unit (as shown in Tables
5 & 6); hence, even if all of the deaths attributed to generators with
two-cylinder Class II engines were to be prevented by the proposed rule
standard, the costs would exceed the benefits for these generators.
Exclusion of generators with two-cylinder engines from the scope of
the rule could create an economic incentive for manufacturers of
generators with larger one-cylinder engines to either switch to two-
cylinder engines for those models, or if they already have two-cylinder
models in their product lines, they could be more likely to drop larger
one-cylinder models from their product lines. The precise impacts of
such business decisions on aggregate net benefits of the rule are not
known at this time, but it would likely be of marginal significance. We
have no evidence that such substitution would occur or, even if it did,
that the impact would be significant. Moreover, the higher cost of
manufacturing the two-cylinder generators could offset any cost
advantage that would result by avoiding the requirements of the
proposed rule.
If it would be technologically feasible and cost-effective for
manufacturers to use smaller two-cylinder engines for generators in
lower power ratings that are associated with greater per-unit societal
costs, the reduction in scope of the rule might also specify a minimum
engine displacement. For example, if this issue were a concern to the
Commission, it could exempt generators with two-cylinder engines, but
only if the two-cylinder models had a displacement above a specified
value of total engine displacement.
The Commission is including class 2 twin-cylinder generators in the
scope of the proposed rule and seeks comments and input on whether
class 2 twin-cylinder generators should be excluded from the scope and
input on possible shifts in the market of generators powered by two-
cylinder engines, such as those discussed above, that might result if
two-cylinder generators were excluded from the scope of the rule. The
Commission seeks comments on what an appropriate limit on displacement
would be if generators with two-cylinder engines above a certain
displacement were excluded from the scope, to avoid creating a market
incentive for small twin-cylinder generators that avoid the scope of
the proposed rule.
3. Alternate Means of Limiting Consumer Exposure: Automatic Shutoff
Systems
CPSC staff considered options for reducing the risk of CO poisoning
that would require portable generators to shut off automatically if
they sensed that a potentially hazardous situation was developing, or
if they were used in locations that are more likely to result in
elevated COHb levels in users. CPSC engineering staff evaluated four
shutoff strategies/technologies: (1) A generator-mounted CO-sensing
system, which would (ideally) sense higher CO levels during operation
indoors and shut off the engine before dangerous levels build up; (2) a
CO-sensing system located away from the generator (e.g., inside the
dwelling) that relies on the user to properly place the sensing unit in
a location where it can communicate with the generator and send a
signal remotely, causing the engine to shut down; (3) a generator-
mounted global-positioning (GPS) system intended to infer operation of
the generator indoors (from detection of reduced satellite signal
strength) and automatically shut down the engine; and (4) applicable to
generators equipped with EFI, an
[[Page 83603]]
algorithm programmed into the engine control unit (ECU) that relies on
system sensors to infer indoor operation, signaling the ECU to shut
down the engine. The findings of the CPSC engineering evaluation
reports on each of the shutoff strategies are summarized in detail in
the briefing memorandum for the proposed rule.
As alternative means of limiting exposure to CO, automatic shutoff
systems could be incorporated into a standard that limits CO production
per hour (such as the draft proposed standard), or they could enable
compliance with an alternative standard that requires generators to
shut off automatically if they are used in conditions that could lead
to accumulation of hazardous levels of CO. Allowing the use of
automatic shutoff systems, as either a supplement to limits on CO
production per hour or under an alternative shutoff standard could
potentially be less costly for manufacturers, and result in greater
reductions in CO poisoning for consumers.
However, CPSC staff does not believe that an automatic shutoff
standard or option is sufficiently proven to be feasible at this time.
As noted, CPSC engineering staff investigated four different approaches
for an automatic shutoff system, and was not able to demonstrate how
any of the shutoff systems could be implemented satisfactorily.
Unresolved concerns with the automatic shutoff technologies studied by
CPSC staff include: (1) Possibly creating a false sense of safety,
which could lead to increased use of portable generators indoors; (2)
alternatives that require CO sensors falsely could identify hazards,
which would detrimentally affect the utility of the generator when used
in proper locations, and could lead to consumers overriding the
mechanism; (3) the system would have to be shown to be durable and
capable of functioning after being stored for long periods and being
used under widely different conditions; and (4) use of algorithms to
shut off engines with ECUs would have to be engine-specific and
tailored to each engine function, requiring a significant amount of
additional testing on this system. These concerns would have to be
resolved before a standard incorporating an automatic shutoff option
could be developed.
4. Different (Longer) Compliance Dates
As noted in the technical rationale for the proposed rule, staff
believes that 1 year is sufficient lead time for manufacturers to
implement the necessary modifications on both one-cylinder and two-
cylinder Class II engines powering generators.\142\ This assessment is
partly based on greater industry experience in manufacturing small
engines with closed-loop EFI for a variety of applications, including
portable generators, since 2006, when the EPA estimated that
manufacturers would need 3 years to 5 years to implement closed-loop
EFI and make necessary engine improvements, if EPA were to adopt more
stringent requirements for its HC+NOX emission standard for
small SI engines. Because of the experience gained by engine
manufacturers in recent years, the Commission thinks 1 year from the
date of publication of the final rule would provide an appropriate
lead-time for generators powered by Class II engines. The Commission is
proposing a later compliance date that would take effect 3 years from
the date of publication of the final rule for generators powered by
smaller engines (handheld and Class I engines). This longer period
addresses manufacturers' concerns that there may be different
challenges associated with accommodating the necessary emission control
technologies on these smaller engines (even though industry has also
gained some limited experience with incorporating fuel-injection on
handheld and Class I engines).
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\142\ Briefing memorandum for staff's briefing package.
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The Commission could decide that the recent industry experience in
manufacturing small engines with EFI, cited in the staff's technical
rationale (Buyer, 2016), while facilitating compliance for some
manufacturers of engines and generators, might not shorten the time
needed by other manufacturers that have not gained relevant experience
in application of EFI technology to their products. Based on recent
discussions with generator manufacturers, a longer time frame before
compliance is required would allow firms more time to design and build
parts in-house, which could be more cost-effective than outsourcing.
Lack of relevant recent experience with incorporating EFI in engine
manufacturing could be more common for small manufacturers of
generators. As noted in the staff's initial regulatory flexibility
analysis, a longer period before the rule becomes effective (or before
compliance is required for generators with smaller engines) would
provide small engine manufacturers more time to develop engines that
would meet the requirements of the proposed rule, and in the case of
small manufacturers of generators that do not also manufacture their
own engines, ``it would provide them with additional time to find a
supplier for compliant engines so that their production of generators
would not be interrupted [and . . . ] for small importers, a later
effective date would provide them with additional time to locate a
supplier of compliant generators.'' \143\
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\143\ Tab M of the staff's briefing package.
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5. Informational Measures
OMB (2003) notes that informational measures often will be
preferable when agencies are considering regulatory action to address a
market failure arising from inadequate information. As discussed
previously, although labels for generators were improved in 2007, with
the introduction of mandatory labels, deaths and injuries from the
improper placement of newly purchased generators suggest that at least
some consumers poorly understand and process the information contained
in the operating instructions and warning labels and consequently,
these consumers continue to put themselves and others at risk through
the improper placement of generators in enclosed areas. Additionally, a
review of injury and market data since improved warning labels have
been required finds that there is not sufficient evidence to conclude
that the label required in the current labeling standard has reduced
the CO fatality risks associated with portable generators. Moreover,
findings of other general studies on the effectiveness of labels ``make
it seem unlikely that any major reductions in fatalities should be
anticipated due to the introduction of these labels.'' \144\
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\144\ Tab H of the staff's briefing package.
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Other informational measures that the Commission could take include
increased provision of information through means such as government
publications, telephone hotlines, or public interest broadcast
announcements. CPSC has previously taken actions to alert consumers to
the dangers of CO poisoning by portable generators, and the Commission
believes that continued involvement in these activities is warranted.
However, evidence of problems in processing information, and continued
occurrence of deaths and injuries from improper use of portable
generators, indicate that informational measures do not adequately
address the risks presented by these products.
6. Taking No Action To Establish a Mandatory Standard
The Commission could take no further regulatory action to establish
a mandatory standard on portable
[[Page 83604]]
generators. Given that some generator manufacturers have demonstrated
that it is technologically feasible to produce generators that emit
significantly lower levels of CO, taking no regulatory action to
establish a mandatory standard would allow manufacturers to market low
CO-emitting generators if they believe that there would be a market for
such products. In addition, it would allow fully informed consumers to
purchase low CO-emitting generators if they value the reduced risk.
However, the Commission does not expect that a significant number of
generators with CO emission rates proposed by the standard would be
marketed voluntarily, at least in the short run.
H. Conclusions From Preliminary Regulatory Analysis
During 2004 to 2012, there was an average of about 73 portable
generator-related deaths and at least 2,800 generator-related nonfatal
injuries annually. The societal costs of these injuries, as described
above, totaled about $820 million annually. During the same period,
there was an average of about 11.1 million portable generators in use,
suggesting about 0.66 deaths and at least 25.2 nonfatal CO poisonings
per 100,000 portable generators in use. Based on indoor air quality
modeling by NIST, and a staff technical evaluation of the predicted
health effects for scenarios and housing characteristics found in the
CPSC incident data, CPSC estimated that the proposed rule would prevent
about one-third of these deaths and injuries.\145\
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\145\ See Tab K of the staff's briefing package.
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The preliminary regulatory analysis evaluated the benefits and
costs of the proposed rule. It distinguished between four categories of
portable generators by engine class and type: (1) Those with handheld
engines with displacement of 80 cc or less; (2) generators with Class I
engines with engine displacement of less than 225 cc; (3) generators
with one-cylinder Class II engines with engine displacement of 225 cc
or more; and (4) two-cylinder class II generators with engine
displacement of 225 cc or more.
Generators with Class I and one-cylinder Class II engines accounted
for about 92.2 percent of portable generators in use over the period
2004 through 2012. Generators with handheld engines (with engine
displacement of 80 cc or less) and two-cylinder Class II engines (with
displacement of 225 cc or more) accounted for 0.7 percent and 7.1
percent of portable generators in use, respectively, over 2004-2012.
The preliminary regulatory analysis suggests that the proposed rule
could have substantial benefits for most generators. The estimated
gross benefits per generator (over its expected product life) ranged
from about $215 to $255 for models with hand-held, Class I, and one-
cylinder Class II engines. However, gross benefits for the units with
two-cylinder Class II engines amounted to only about $4 per unit.
The estimated costs of the proposed rule were generally similar
across generator types, ranging from about $110 to $120 per generator
for the models with handheld, Class I, and one-cylinder Class II
engines, to about $140 for the models with two-cylinder Class I
engines. The retail price increases likely to result from these higher
costs could reduce portable generator sales by roughly 50,000 units
annually, an overall sales reduction of about 3 to 4 percent. The
relative impact on handheld generator sales could be greater because of
the lower base price of these models.
Given these benefit and cost estimates, net benefits (i.e.,
benefits minus costs) ranged from about $100 to about $140 per
generator for the models with handheld, Class I, and one-cylinder Class
II engines. However, net benefits were a negative $135 for the models
with two-cylinder Class II engines (i.e., benefits of $4 per generator
minus costs of $139 per generator). Consequently, net benefits for
portable generators as a group would be maximized by excluding the
models with two-cylinder Class II engines from the rule.
Estimated net benefits can be converted to aggregate annual
estimates, given estimates of the annual sales of portable generators.
The estimated aggregate net benefits, based on 1 year's sales of the
generators with handheld, Class I, and one-cylinder Class II engines
amounted to $153 million. Including the models with two-cylinder Class
II engines (which account for only about 5 percent of portable
generators sold in recent years) under the requirements of the standard
would reduce aggregate net benefits to about $145 million annually.
The sensitivity analysis supported the findings of the base
analysis. None of the inputs used in the sensitivity analysis altered
the main findings that there would be positive net benefits for the
generators with handheld, Class I, and one-cylinder Class II engines,
but negative net benefits for the generators with two-cylinder Class II
engines.
Additionally, we note that benefits of the proposed rule were
estimated based on an assumption that consumer behavior would not
change in response to knowledge of the reductions in CO emissions from
generators. However, a perceived reduction in the risk associated with
using the generators in unsafe environments may increase the likelihood
that some consumers will use their generators in the house, in the
garage, or in outside locations that are near openings to the house--
behaviors the CPSC recommends against. Although such a response could
offset the expected benefits from the proposed rule, staff anticipates
that any impact would be minimal. On the other hand, the benefits
estimates were based on 503 of the 659 CO-related deaths during 2004
through 2012. These were the deaths occurring in fixed-residential or
similar structures (e.g., detached and attached houses, and fixed
mobile homes) that could be modeled by NIST. CPSC staff believes that
some unquantified proportion of the remaining 156 deaths that were not
modeled by NIST, because they occurred at non-fixed home locations
(e.g., temporary structures such as trailers, horse trailers,
recreational vehicles, or tents), and some that occurred when portable
carbureted generators were operated outdoors, would have been
prevented.\146\ If so, the benefits estimates would have been somewhat
higher than presented in this analysis.
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\146\ Tab K of the staff's briefing package.
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XI. Initial Regulatory Flexibility Analysis
This section provides an analysis of the impact on small businesses
of a proposed rule that would establish a mandatory safety standard for
portable generators. Whenever an agency is required to publish a
proposed rule, section 603 of the Regulatory Flexibility Act (5 U.S.C.
601-612) requires that the agency prepare an initial regulatory
flexibility analysis (IRFA) that describes the impact that the rule
would have on small businesses and other entities. An IRFA is not
required if the head of an agency certifies that the proposed rule will
not have a significant economic impact on a substantial number of small
entities. 5 U.S.C. 605. The IRFA must contain:
(1) A description of why action by the agency is being considered;
(2) a succinct statement of the objectives of, and legal basis for,
the proposed rule;
(3) a description of and, where feasible, an estimate of the number
of small entities to which the proposed rule will apply;
[[Page 83605]]
(4) a description of the projected reporting, recordkeeping and
other compliance requirements of the proposed rule, including an
estimate of the classes of small entities which will be subject to the
requirement and the type of professional skills necessary for
preparation of the report or record; and
(5) identification to the extent practicable, of all relevant
Federal rules which may duplicate, overlap or conflict with the
proposed rule.
An IRFA must also contain a description of any significant
alternatives that would accomplish the stated objectives of the
applicable statutes and that would minimize any significant economic
impact of the proposed rule on small entities. Alternatives could
include: (1) Establishment of differing compliance or reporting
requirements that take into account the resources available to small
businesses; (2) clarification, consolidation, or simplification of
compliance and reporting requirements for small entities; (3) use of
performance rather than design standards; and (4) an exemption from
coverage of the rule, or any part of the rule thereof, for small
entities.
A. Reason for Agency Action
The proposed rule would limit the rate of CO emitted by portable
generators and is intended to reduce the risk of death or injury
resulting from the use of a portable generator in or near an enclosed
space. The Directorate for Epidemiology, Division of Hazard Analysis
(EPHA) reports that there were 659 deaths involving portable generators
from 2004 to 2012, an average of about 73 annually.\147\ Furthermore,
there was a minimum of 8,703 nonfatal CO poisonings involving portable
generators that were treated in hospital emergency departments from
2004 through 2012, or a minimum of about 967 annually (Hanway, 2015);
and, as discussed in the preliminary regulatory analysis, there were an
additional 16,600 medically attended injuries treated in other
settings, or an estimated 1,851 per year. The societal costs of both
fatal and nonfatal CO poisoning injuries involving portable generators
amounted to about $821 million ($637 million for fatal injuries + $184
million for nonfatal injuries) on an annual basis. The proposed
standard is expected to significantly reduce generator-related injuries
and deaths and the associated societal costs.
---------------------------------------------------------------------------
\147\ Tab A of the staff's briefing package.
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B. Objectives of and Legal Basis for the Rule
The objective of the proposed rule is to reduce deaths and injuries
resulting from exposure to CO associated with portable electric
generators being used in or near confined spaces. The Commission
published an ANPR in December 2006, which initiated this proceeding to
evaluate regulatory options and potentially develop a mandatory
standard to address the risks of CO poisoning associated with the use
of portable generators. The proposed rule is being promulgated under
the authority of the Consumer Product Safety Act (CPSA).
C. Small Entities to Which the Rule Will Apply
The proposed rule would apply to small entities that manufacture or
import SI portable generators. Based on data collected by Power Systems
Research, Trade IQ, and general market research, the Commission has
identified more than 70 manufacturers of generators that have at some
time supplied portable generators to the U.S. market. However, most of
these manufacturers were based in other countries. The Commission has
identified 20 domestic manufacturers of gasoline-powered portable
generators, of which 13 would be considered small based on the Small
Business Administration (SBA) size guidelines for North American
Industry Classification System (NAICS) category 335312 (Motor and
Generator Manufacturing), which categorizes manufacturers as small if
they have fewer than 1,250 employees. Four of the small manufacturers
are engaged primarily in the manufacture or supply of larger,
commercial, industrial, or backup generators, or other products, such
as electric motors, which would not be subject to the draft standard.
For the other nine small manufacturers, portable generators could
account for a significant portion of the firms' total sales. Of these
nine small, domestic manufacturers, six have fewer than 99 employees;
one has between 100 and 199 employees; another firm has between 200 and
299 employees; and one has between 300 and 399 employees, based on firm
size data from Hoovers, Inc., and interviews with several
manufacturers.
In some cases, a small manufacturer may be responsible for
designing its own brand of generators but outsource the actual
production of the generators to other manufacturers, which are often
based in China. Other small manufacturers may assemble using components
(including engines) purchased from other suppliers. There may be some
small manufacturers that manufacture or fabricate some components of
the generators, in addition to assembling them.
Using the same sources of data described above, the Commission
identified more than 50 firms that have imported gasoline-powered
portable generators. However, in some cases, the firms have not
imported generators regularly, and generators appear to account for an
insignificant portion of these firm's sales. Of these firms, the
Commission believes that 20 may be small importers of gasoline-powered
portable generators that could be affected by the proposed rule.
Importers were considered to be a small business if they had fewer than
200 employees, based on the SBA guidelines for NAICS category 423610
(Electrical Apparatus and Equipment, Wiring Supplies, and Related
Equipment Merchant Wholesalers) or $11.0 million in average annual
receipts, based on the SBA guidelines for NAICS category 443141
(Household Appliance Stores). Of the 20 small, potential importers
staff identified, all have 50 or fewer employees, based on firm size
data from Hoovers, Inc.
D. Compliance, Reporting, and Record Keeping Requirements of Proposed
Rule
The proposed rule would establish a performance standard that would
limit the rate of CO that could be produced by portable generators that
are typically used by consumers for electrical power in emergencies or
other circumstances in which the electrical power has been shut off or
is not available. The performance standard would be based on the
generator's weighted CO emissions rate, and stated in terms of grams/
hour (g/hr), depending upon the class \148\ of the engine powering the
generator. Generators powered by handheld engines and Class I engines
would be required to emit CO at a
[[Page 83606]]
weighted rate that is no more than 75 grams per hour (g/hr). Generators
powered by Class II engines with a single cylinder would be required to
emit CO at a weighted rate that is no more than 150 g/hr. Generators
powered by Class II engines with two (or twin) cylinders, which are
generally larger than others in the class, and are believed to comprise
a very small share of the consumer market, would be required to emit CO
at a weighted rate of no more than 300 g/hr.
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\148\ Because most of the generators that were associated with
fatal CO poisoning incidents reported to CPSC were gasoline-fueled,
staff has chosen to set the performance standard based on the U.S.
Environmental Protection Agency's (EPA) classification of the small
SI engine powering the generator and the number of cylinders the
engine has. The EPA broadly categorizes small SI engines as either
non-handheld or handheld, and within each of those categories,
further distinguishes them into different classes, which are based
upon engine displacement. Nonhandheld engines are divided into Class
I and Class II, with Class I engines having displacement above 80 cc
up to 225 cc and Class II having displacement at or above 225 cc but
maximum power of 19 kilowatts (kW). Handheld engines, which are
divided into Classes III, IV, and V, are all at or below 80 cc.
Staff chose to divide non-handheld Class II engines based on whether
the engine had a single cylinder or twin cylinders.
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Section 14 of the CPSA requires that manufacturers, importers, or
private labelers of a consumer product subject to a consumer product
safety rule to certify, based on a test of each product or a reasonable
testing program that the product complies with all rules, bans or
standards applicable to the product. The proposed rule details the test
procedure that the Commission would use to determine compliance with
the standard, but also provides that any test procedure may be used
that will accurately determine the emission level of the portable
generator. However, for certification purposes, manufacturers must
certify that the product conforms to the standard, based on either a
test of each product, or any reasonable alternative method to
demonstrate compliance with the requirements of the standard. For
products that manufacturers certify, manufacturers would issue a
general certificate of conformity (GCC).
The requirements for GCCs are in Section 14 of the CPSA. Among
other requirements, each certificate must identify the manufacturer or
private labeler issuing the certificate and any third party conformity
assessment body, on whose testing the certificate depends, the place of
manufacture, the date and place where the product was tested, each
party's name, full mailing address, telephone number, and contact
information for the individual responsible for maintaining records of
test results. The certificates must be in English. The certificates
must be furnished to each distributor or retailer of the product and to
the CPSC, if requested.
1. Costs of Proposed Rule That Would Be Incurred by Small Manufacturers
The most likely method for manufacturers of portable generators to
comply with the proposed CO emissions requirement is converting to the
use of closed-loop electronic fuel-injection (EFI) systems instead of
conventional carburetors, to control the delivery of gasoline to the
pistons of generator engines. Manufacturers also are likely to use
catalytic converters in the mufflers of the generator engines. As
discussed in the preliminary regulatory analysis in Section X, the cost
to manufacturers for complying with the proposed rule is expected to
be, on average, about $114 per unit for generators with handheld
engines (1.1% of unit sales between 2010 and 2014), $113 per unit for
generators with Class I engines (57.8% of unit sales between 2010 and
2014); $110 for those with single cylinder Class II engines (36.4% of
unit sales between 2010 and 2014); and $138 for those with twin
cylinder Class II engines (4.7% of unit sales between 2010 and 2014).
These estimates include the variable costs related to EFI,
including an oxygen sensor for a closed-loop system, a battery and
alternator or regulator; and 3-way catalysts. The estimates also
include the fixed costs associated with the research and development
required to redesign the generators, tooling costs, and the costs
associated with testing and certification that the redesigned engines
comply with the EPA requirements for exhaust constituents they
regulate, HC+NOX and CO emissions.\149\
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\149\ The modifications to small SI engines to comply with the
CO emission requirements would likely require engine manufacturers
to seek certifications (as new engine families) under EPA
requirements for HC+NOX and CO, with the attendant costs
for fees and testing, which could be passed on to generator
manufacturers that purchase the engines to power their products.
Some of the larger manufacturers of portable generators are
vertically-integrated firms that also manufacture the engines that
power their products. These testing and certification requirements
are to meet EPA requirements and are in addition to the testing and
certification requirements of Section 14 of the CPSA.
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Manufacturers likely would incur some additional costs to certify
that their portable generators meet the requirements of the proposed
rule, as required by Section 14 of the CPSA. The certification must be
based on a test of each product or a reasonable testing program.
Manufacturers may use any testing method that they believe is
reasonable and are not required to use the same test method that would
be used by CPSC to test for compliance. Based on information from a
testing laboratory, the cost of the testing might be more than $6,000
per generator model, although it may be possible to use the results
from other tests that manufacturers already may be conducting, such as
testing to ensure that the engines comply with EPA requirements, per 40
CFR part 1054, for HC+NOX and CO emissions to certify that
the generator meets the requirements of the proposed rule.
Manufacturers and importers also may rely upon testing completed by
other parties, such as their foreign suppliers, in the case of
importers, or the engine suppliers in the case of manufacturers, if
those tests provide sufficient information for the manufacturers or
importers to certify that the generators comply with the proposed rule.
The Commission welcomes comments from the public regarding the cost
or other impacts of the certification requirements under Section 14 of
the CPSA and whether it would be feasible to use the results of tests
conducted for certifying compliance with EPA requirements to certify
compliance with the proposed rule.
2. Impacts on Small Businesses
Manufacturers
To comply with the proposed rule, small manufacturers would incur
the costs described above to redesign and manufacture generators that
comply with the CO emissions requirements and to certify that they
comply. However, to the extent that the volume of generators produced
by small manufacturers is lower than that of the larger manufacturers,
the costs incurred by smaller manufacturers may be higher than the
average costs reported above. One reason to expect that costs for
lower-volume manufacturers could be higher than average is that some of
the costs are fixed. For example, research and development costs were
estimated to be about $203,000, on average, for Class II engines and
about $316,000 for Class I engines. On a per-unit basis, the
preliminary regulatory analysis estimated that these costs would
average about $4 for Class I engines and $3 for Class II engines, but
for manufacturers with a production volume only one-half the average
production volume, the per-unit costs would be twice the average.
For lower-volume producers, the per-unit costs of the components
necessary to modify their engines might also be higher than those for
higher-volume producers. As discussed in the preliminary regulatory
analysis, generators that meet the requirements of the proposed rule
would probably use closed-loop electronic fuel-injection instead of
conventional carburetors. Therefore, manufacturers would incur the
costs of adding components associated with EFI to the generator,
including injectors, pressure regulators, sensors, fuel pumps, and
batteries. Based on information obtained from a generator manufacturer,
the cost of these components might be as much as 35 percent higher for
a manufacturer that purchased only a few thousand units at a time, as
opposed to more than 100,000 units.
[[Page 83607]]
While the cost for small, low-volume manufacturers that manufacture
their own engines might be higher than for high-volume manufacturers,
small portable generator manufacturers often do not manufacture the
engines used in their generators, but obtain them from engine
manufacturers such as Honda, Briggs and Stratton, and Kohler, as well
as several engine manufacturers based in China. These engine
manufacturers often supply the same engines to other generator or
engine-driven tool manufacturers. Because these engine manufacturers
would be expected to have higher production volumes and can spread the
fixed research and development and tooling costs over a higher volume
of production, the potential disproportionate impact on lower-volume
generator producers might be mitigated to some extent.
As discussed in the preliminary regulatory analysis, the retail
prices CPSC observed for portable generators from manufacturers and
importers of all sizes ranged from a low of $133 to $4,399, depending
upon the characteristics of the generator. On a per-unit basis, the
proposed rule is expected to increase the costs of generators by an
average of $110 to $140. Generally, impacts that exceed 1 percent of a
firm's revenue are considered to be potentially significant. Because
the estimated average cost per generator would be between about 3
percent and 80 percent of the retail prices (or average revenue) of
generators, the proposed rule could have a significant impact on
manufacturers and importers that receive a significant portion of their
revenue from the sale of portable generators.
Based on a conversation with a small manufacturer, CPSC staff
believes that the proposed rule may have a disproportionate impact on
generator manufacturers that compete largely on the basis of price,
rather than brand name or reputation. Currently, CPSC cannot identify
how many of the nine domestic small manufacturers of engines compete on
the basis of price. One reason for the disproportionate impact is that
consumers of the lower priced generators are probably more price
sensitive than consumers of the brand name generators and may be more
likely to reduce or delay their purchases of generators in response to
the cost increases that would be expected to result from the proposed
rule. A second reason that manufacturers that compete largely on the
basis of price could be disproportionately impacted is that brand name
generator manufacturers might have more options for absorbing the cost
increases that result from the proposed rule. For example a high-end
generator manufacturer might be able to substitute a less expensive,
but still adequate engine for a name brand engine that they currently
might be using. On the other hand, manufacturers that have been
competing primarily on the basis of price are more likely to have
already made such substitutions and will have fewer options for
absorbing any cost increases. As a result, the price differential
between generators aimed at the low-end or price-conscious market
segments and the name brand generators will be reduced, which could
affect the ability of the manufacturers of generators aimed at the
price conscious market to compete with the name-brand manufacturers.
Importers
For many small importers, the impact of the proposed rule would be
expected to be similar to the impact on small manufacturers. One would
expect that the foreign suppliers would pass much of the costs of
redesigning and manufacturing portable generators that comply with the
proposed rule to their domestic distributors. Therefore, the cost
increases experienced by small importers would be similar to those
experienced by small manufacturers. As with small manufacturers, the
impact of the proposed rule might be greater for those importers that
primarily compete on the basis of price. Currently, CPSC cannot
identify how many of the 20 domestic, small importers of engines
compete on the basis of price.
In some cases, the foreign suppliers might opt to withdraw from the
U.S. market, rather than incur the costs of redesigning their
generators to comply with the proposed rule. If this occurs, the
domestic importers would have to find other suppliers of portable
generators or exit the portable generator market. Exiting the portable
generator market could be considered a significant impact, if portable
generators accounted for a significant percentage of the firm's
revenue.
Small importers will be responsible for issuing a GCC certifying
that their portable generators comply with the proposed rule should it
become final. However, importers may rely upon testing performed and
GCCs issued by their suppliers in complying with this requirement.
E. Federal Rules That May Duplicate, Overlap, or Conflict With the
Proposed Rule
The Commission has not identified any federal rules that duplicate
or conflict with the proposed rule. The EPA promulgated a standard in
2008 for small spark-ignited engines that set a maximum rate for CO
emissions. However, the maximum level set by the EPA is higher than the
proposed CPSC standard for portable generators.
F. Alternatives Considered To Reduce the Burden on Small Entities
Under section 603(c) of the Regulatory Flexibility Act, an initial
regulatory flexibility analysis should ``contain a description of any
significant alternatives to the proposed rule which accomplish the
stated objectives of the applicable statutes and which minimize any
significant impact of the proposed rule on small entities.'' CPSC
examined several alternatives to the proposed rule that could reduce
the impact on small entities. These include: (1) Less stringent CO
emission rates; (2) limit coverage to one-cylinder engines; (3) an
option for reducing consumer exposure to CO by using an automatic
shutoff; (4) establishing alternative compliance dates; (5)
informational measures; or (6) taking no action. These alternatives are
discussed in more detail in Section X.G.
G. Summary and Request for Comments Regarding Potential Impact on Small
Business
The Commission has identified about nine small generator
manufacturers and about 20 small generator importers that would be
impacted by the proposed rule.
The most likely means of complying with the proposed rule would be
to use closed-loop electronic fuel-injection (EFI) systems, instead of
conventional carburetors, to control the delivery of gasoline to the
pistons of generator engines and to use catalytic converters in the
mufflers of the generator engines to be able to meet the EPA's
HC+NOX emission standards. The Commission estimates that, on
average, the requirements will increase the costs of generator
manufacturers by about $110 and $140, depending upon engine type. The
costs might be higher than average for lower-volume manufacturers.
Manufacturers and suppliers that serve the low-end of the market
and compete mostly on the basis of price might be more severely
impacted by the proposed rule because their customers may be more price
sensitive; and compared with larger manufacturers, they may not have
the same options of reducing other costs to mitigate the impact of the
proposed rule on the price of generators. Suppliers of name-brand
generators or ones that compete on basis other than price might be able
to make other adjustments, such as using less expensive engines to
mitigate the
[[Page 83608]]
impact of the proposed rule on the price of their generators. CPSC
currently cannot identify how many of the nine domestic, small
manufacturers or the 20 domestic, small importers of engines compete on
the basis of price.
Generator manufacturers and importers will be responsible for
certifying that their products comply with the requirements of the
proposed rule. Testing and certification costs can have a
disproportionate impact on small manufacturers, depending upon the cost
of the tests and volume of production, relative to larger
manufacturers. However, some of these testing costs might be mitigated,
if manufacturers could use the results of testing already being
conducted (such as, for example, testing to certify compliance with EPA
requirements), to offset some of the testing costs required for
certification with the proposed rule.
The Commission invites comments on this IRFA and the potential
impact of the proposed rule on small entities, especially small
businesses. Small businesses that believe they will be affected by the
proposed rule are especially encouraged to submit comments. The
comments should be specific and describe the potential impact,
magnitude, and alternatives that could reduce the impact of the
proposed rule on small businesses.
In particular, the Commission seeks comment on:
The types and magnitude of manufacturing costs that might
disproportionately impact small businesses or that were not considered
in this analysis;
the costs of the testing and certification requirements of
the proposed rule, including whether EPA testing can be used to meet
the certification requirements for the proposed rule;
whether other factors not considered in this analysis
could be significant, such as EPA's Averaging, Banking and Trading
(ABT) program that could allow manufacturers of engine families that do
have low CO emissions to meet the proposed rule and that also have very
low HC+NOX emissions to ``buy credits'' in the ABT program,
thus allowing their other engine families to exceed HC+NOX
limits;
differential impacts of the proposed rule on small
manufacturers or suppliers that compete in different segments of the
portable generator market; and finally,
CPSC would be interested in any comments that provide
alternatives that would minimize the impact on small businesses but
would still reduce the risk of CO poisoning associated with generators.
XII. Environmental Considerations
The Commission's regulations address whether CPSC is required to
prepare an environmental assessment (EA) or an environmental impact
statement (EIS). 16 CFR 1021.5. Those regulations state CPSC's actions
that ordinarily have ``little or no potential for affecting the human
environment,'' and therefore, are categorically excluded from the need
to prepare an EA or EIS. Among those actions are rules, such as the
portable generator NPR, which provide performance standards for
products. Id. 1021.5(c)(1).
XIII. Executive Order 12988 (Preemption)
In accordance with Executive Order 12988 (February 5, 1996), the
CPSC states the preemptive effect of the proposed rule, as follows:
The regulation for portable generators is proposed under authority
of the CPSA. 15 U.S.C. 2051-2089. Section 26 of the CPSA provides:
``whenever a consumer product safety standard under this Act is in
effect and applies to a risk of injury associated with a consumer
product, no State or political subdivision of a State shall have any
authority either to establish or to continue in effect any provision of
a safety standard or regulation which prescribes any requirements as to
the performance, composition, contents, design, finish, construction,
packaging or labeling of such product which are designed to deal with
the same risk of injury associated with such consumer product, unless
such requirements are identical to the requirements of the Federal
Standard''. 15 U.S.C. 2075(a). Upon application to the Commission, a
state or local standard may be excepted from this preemptive effect if
the state or local standard: (1) Provides a higher degree of protection
from the risk of injury or illness than the CPSA standard, and (2) does
not unduly burden interstate commerce. In addition, the federal
government, or a state or local government, may establish or continue
in effect a non-identical requirement for its own use that is designed
to protect against the same risk of injury as the CPSC standard if the
federal, state, or local requirement provides a higher degree of
protection than the CPSA requirement. 15 U.S.C. 2075(b).
Thus, the portable generator requirements proposed in this Federal
Register would (if finalized) preempt non-identical state or local
requirements for portable generators designed to protect against the
same risk of injury and prescribing requirements regarding the
performance, composition, contents, design, finish, construction,
packaging or labeling of portable generators.
XIV. Certification
Section 14(a) of the CPSA requires that products subject to a
consumer product safety rule under the CPSA, or to a similar rule, ban,
standard or regulation under any other act enforced by the Commission,
must be certified as complying with all applicable CPSC-enforced
requirements. 15 U.S.C. 2063(a). A final rule on portable generators
would subject portable generators to this certification requirement.
XV. Effective Date
The CPSA requires that consumer product safety rules take effect
not later than 180 days from their promulgation unless the Commission
finds there is good cause for a later date. 15 U.S.C. 2058(g)(1). The
Commission proposes that the rule would take effect 1 year from the
date of publication of the final rule for generators powered by Class
II engines and three years from the date of publication of the final
rule for generators powered by handheld and Class I engines.
Because of the experience gained by engine manufacturers in recent
years in designing and building EFI small SI engines, the Commission
believes one year from the date of publication of the final rule would
provide an appropriate lead-time for generators powered by one and two
cylinder Class II engines. The Commission is proposing an effective
date of three years from the date of publication of the final rule for
generators powered by handheld and Class I engines. This longer period
to become compliant addresses manufacturers' concerns that there may be
different challenges associated with accommodating the necessary
emission control technologies on these smaller engines. In addition,
later compliance dates could potentially reduce the impact on
manufacturers of generators, including small manufacturers, by
providing them with more time to develop engines that would meet the
requirements of the proposed rule, or, in the case of small
manufacturers that do not manufacture the engines used in their
generators, by providing them with additional time to find a supplier
for compliant engines so that their production of generators would not
be interrupted.
[[Page 83609]]
XVI. Proposed Findings
The CPSA requires the Commission to make certain findings when
issuing a consumer product safety standard. Specifically, the CPSA
requires that the Commission consider and make findings about the
degree and nature of the risk of injury; the number of consumer
products subject to the rule; the need of the public for the product
and the probable effect on utility, cost, and availability of the
product; and other means to achieve the objective of the rule, while
minimizing the impact on competition, manufacturing, and commercial
practices. The CPSA also requires that the Commission find that the
rule is reasonably necessary to eliminate or reduce an unreasonable
risk of injury associated with the product and issuing the rule must be
in the public interest. 15 U.S.C. 2058(f)(3).
In addition, the Commission must find that: (1) If an applicable
voluntary standard has been adopted and implemented, that compliance
with the voluntary standard is not likely to reduce adequately the risk
of injury, or compliance with the voluntary standard is not likely to
be substantial; (2) that benefits expected from the regulation bear a
reasonable relationship to its costs; and (3) that the regulation
imposes the least burdensome requirement that would prevent or
adequately reduce the risk of injury. Id. These findings are discussed
below.
Degree and nature of the risk of injury.
Carbon monoxide is a colorless, odorless, poisonous gas formed
during incomplete combustion of fossil fuels, such as the fuels used in
engines that power portable generators. Mild CO poisoning symptoms
include headaches, lightheadedness, nausea, and fatigue. More severe CO
poisoning can result in progressively worsening symptoms of vomiting,
confusion, loss of consciousness, coma, and ultimately, death. The high
CO emission rate of current generators can result in situations in
which the COHb levels of exposed individuals rise suddenly and steeply,
causing them to experience rapid onset of confusion, loss of muscular
coordination, and loss of consciousness.
As of May 21, 2015, CPSC databases contained reports of at least
751 generator-related consumer CO poisoning deaths resulting from 562
incidents, which occurred from 2004 through 2014. Due to incident
reporting delays, statistics for the two most recent years, 2013 and
2014, are incomplete, because data collection is still ongoing, and the
death count most likely will increase in future reports.
Based on NEISS, the Commission estimates that for the 9-year period
of 2004 through 2012, there were 8,703 CO injuries seen in emergency
departments (EDs) associated with portable generators. The Commission
considers this number to represent a lower bound on the true number of
generator-related CO injuries treated in EDs from 2004-2012. According
to Injury Cost Model (ICM) estimates, there were an additional 16,660
medically-attended CO injuries involving generators during 2004-2012.
Number of consumer products subject to the rule.
For the U.S. market for the years 2010 through 2014, about 6.9
million gasoline-powered portable generators were shipped for consumer
use, or an average of about 1.4 million units per year. Shipments of
nearly 1.6 million units in 2013 made it the peak year for estimated
sales during this period. Consumer demand for portable generators from
year-to-year fluctuates with major power outages, such as those caused
by tropical or winter storms. Portable generators purchased by
consumers and in household use generally range from under 1 kW of rated
power up to perhaps 15 kW of rated power. In the last 10 to 15 years,
the U.S. market has shifted towards smaller, less powerful units.
The need of the public for portable generators and the effects of
the rule on their utility, cost, and availability.
Portable generators that are the subject of the proposed standard
commonly are purchased by consumers to provide electrical power during
emergencies (such as during outages caused by storms), during other
times when electrical power to the home has been shut off, when power
is needed at locations around the home without access to electricity,
and for recreational activities (such as during camping or recreational
vehicle trips).
The proposed rule is based on technically feasible CO emission
rates, so that the function of portable generators is unlikely to be
adversely affected by the rule. Moreover, there may be a positive
change in utility in terms of fuel efficiency, greater ease of
starting, product quality, and safety of portable generators. There may
be a negative effect on the utility of portable generators, however, to
the extent consumers are unable to purchase generators due to increased
retail prices.
In terms of retail price information, the Commission's review found
that generators with handheld engines ranged in price from $133 to
$799, with an average price of about $324. Generators with non-handheld
Class I engines had a wide price range, from $190 to over $2,000, with
an average price of $534. Generators with one-cylinder Class II engines
ranged in price from $329 to $3,999, with an average price of $1,009.
Generators with two-cylinder Class II engines ranged in price from
$1,600 to $4,999, and the average price of these units was $2,550.
Aggregate estimated compliance costs to manufacturers of portable
generators average approximately $113 per unit for engine and muffler
modifications necessary to comply with the CO emission requirements of
the proposed standard. The net estimated manufacturing costs per unit
to comply with the proposed standard is $114 for handheld engines, $113
for Class I engines, $110 for Class II, one cylinder engines, and $138
for Class II, two cylinder engines.
The expected product modifications to produce complying generators
(EFI & catalysts) are available to manufacturers, and the Commission
does not have any indication that firms would exit the market because
of the rule. Therefore, the availability of portable generators would
not likely be affected by the rule.
Other means to achieve the objective of the rule, while minimizing
the impact on competition and manufacturing.
The Commission considered alternatives to achieving the objective
of the rule of reducing unreasonable risks of injury and death
associated with portable generators. For example, the Commission
considered less stringent CO emission rates for portable generators;
however, cost savings from less-stringent CO emission requirements
likely would be less than expected reductions in the benefits, so that
the net benefits of the rule probably would decrease under this
regulatory alternative. The Commission also considered including an
option for reducing CO emissions through use of automatic shutoff
systems, which could potentially reduce the impact of the proposed rule
by providing an additional option for complying with the proposed rule;
however, because of unresolved issues concerning an automatic shutoff,
the Commission does not believe that a regulatory alternative based on
automatic shutoff technology instead of reduced emissions is feasible
for hazard reduction at this time.
Unreasonable risk.
As of May 21, 2015, CPSC databases contained reports of at least
751 generator-related consumer CO poisoning deaths resulting from 562
incidents, which occurred from 2004 through 2014. Due to incident
reporting
[[Page 83610]]
delays, statistics for the two most recent years, 2013 and 2014, are
incomplete, because data collection is still ongoing, and the death
count most likely will increase in future reports.
Based on NEISS, the Commission estimates that for the 9-year period
of 2004 through 2012, there were 8,703 CO injuries seen in emergency
departments (EDs) associated with portable generators. The Commission
considers this number to represent a lower bound on the true number of
generator-related CO injuries treated in EDs from 2004-2012. According
to Injury Cost Model (ICM) estimates, there were an additional 16,660
medically-attended CO injuries involving generators during 2004-2012.
The Commission estimates that the rule would result in aggregate
net benefits of about $145 million annually. On a per-unit basis, the
Commission estimates the present value of the expected benefits per
unit for all units to be $227; the expected costs to manufacturers plus
the lost consumer surplus per unit to be $116; and the net benefits per
unit to be $110. The Commission concludes preliminarily portable
generators pose an unreasonable risk of injury and finds that the
proposed rule is reasonably necessary to reduce that unreasonable risk
of injury.
Public interest.
This proposed rule is intended to address an unreasonable risk of
injury and death posed by portable generators. The Commission believes
that adherence to the requirements of the proposed rule will reduce
portable generator deaths and injuries in the future; thus, the rule is
in the public interest.
Voluntary standards.
The Commission is aware of two U.S. voluntary standards that are
applicable to portable generators, UL 2201--Safety Standard for
Portable Generator Assemblies, and ANSI/PGMA G300-2015--Safety and
Performance of Portable Generators. These standards include the same
requirements set forth in the mandatory CPSC portable generator label
but do not otherwise address the risks related to CO poisoning. The
Commission does not believe the standards are adequate because they
fail to address the risk of CO hazard beyond the CPSC mandatory
labeling requirement. The Commission is unaware of any portable
generator that has been certified to either of the standards, and as
such it is unlikely whether there would be substantial compliance with
it if CO emissions requirements were incorporated.
Relationship of benefits to costs.
The aggregate annual benefits and costs of the rule are estimated
to be about $298 million and $153 million, respectively. Aggregate net
benefits from the rule, therefore, are estimated to be about $145
million annually. On a per unit basis, the Commission estimates the
present value of the expected benefits per unit for all units to be
$227. The Commission estimates the expected costs to manufacturers plus
the lost consumer surplus per unit to be $116. Based on this analysis,
the Commission preliminarily finds that the benefits expected from the
rule bear a reasonable relationship to the anticipated costs of the
rule.
Least burdensome requirement that would adequately reduce the risk
of injury.
The Commission considered less-burdensome alternatives to the
proposed rule on portable generators, but preliminarily concluded that
none of these alternatives would adequately reduce the risk of injury.
(1) The Commission considered not issuing a mandatory rule, but
instead relying upon voluntary standards. As discussed previously, the
Commission does not believe that either voluntary standard adequately
addresses the CO risk of injury and death associated with portable
generators. Furthermore, in the absence of any indication that a
portable generator has been certified to either standard, the
Commission cannot determine that there would be substantial compliance
by industry.
(2) The Commission considered excluding portable generators with
two cylinder Class II engines from the scope of the rule. The
Commission estimates that net benefits of the proposed rule range from
about $100 to about $140 per generator for the models with handheld,
Class I and one-cylinder Class II engines. However, the Commission
estimates net benefits of negative $135 for the models with two-
cylinder Class II engines. Consequently, excluding portable generators
with two cylinder Class II engines would result in a less burdensome
alternative. However, it is possible that exclusion of generators with
two-cylinder Class II engines from the scope of the rule could create
an economic incentive for manufacturers of generators with larger one-
cylinder engines to either switch to two-cylinder engines for those
models, or if they already have two-cylinder models in their product
lines, they could be more likely to drop larger one-cylinder models
from their product lines. Because the Commission lacks more specific
information on the generators with Class II twin cylinder engines, the
Commission is proposing this rule with the broader scope of including
these generators. The Commission welcomes comments on inclusion of
portable generators with Class II twin cylinder engines, or Class 2
twin cylinder generators, in the scope of the rule.
(3) The Commission considered higher allowable CO emission rates,
which might result in costs savings from lower costs associated with
catalysts (if they would not be required, or if less-costly materials
could suffice), less-extensive engine modifications (other than EFI-
related costs) and less-extensive generator housing modifications (if
housing enlargement and other retooling would be minimized). However,
based on Commission estimates, it seems likely that cost savings from
less-stringent CO emission requirements would be less than expected
reductions in benefits. Therefore, the Commission is not proposing this
alternative.
XVII. Ex Ante Retrospective Review
As set forth in the Commission's Plan for Retrospective Review of
Existing Rules (Retrospective Review Plan) (http://www.cpsc.gov/Global/Regulations-Laws-and-Standards/Rulemaking/DraftrulereviewplanSeptember2015Final.pdf) and consistent with the
Regulatory Flexibility Act, as applicable, the Commission has
established certain methods and processes for identifying and
reconsidering certain rules that warrant repeal or modification,
including rules that would benefit from strengthening, complementing,
or modernizing. Consistent with the Retrospective Review Plan's methods
and procedures, which permit the Commission to include retrospective
review provisions in new rulemakings, the Commission is requesting
comments on whether to develop ex ante criteria for the retrospective
review of this proposed rule.
XVIII. Request for Comments
We invite all interested persons to submit comments on any aspect
of the proposed rule. More specifically, the Commission seeks comments
on the following:
The cost or other impacts of the certification
requirements under Section 14 of the CPSA and whether it would be
feasible to use the results of tests conducted for certifying
compliance with EPA requirements to certify compliance with the
proposed rule;
The product manufacture or import limits and the base
period in the proposed anti-stockpiling provision;
[[Page 83611]]
Prospective use (e.g., costs, applicability and
challenges) of battery-less EFI for portable generators;
Costs of new designs and tooling that may be required for
generator frames and housings to accommodate additional components,
such as batteries for generators with handheld or Class I engines, and
to address reported concerns with heat dissipation.
Information on potential challenges in accommodating new
features in handheld and Class I engines to comply with the proposed
rule, as well as on components and technologies that might be available
to meet these challenges and moderate the impacts of the proposed rule
on handheld and Class I engines.
Costs per unit element for testing and certification,
including what additional costs per unit element might be if the
Commission required specific testing requirements;
Costs firms experience with testing and certification of
engines for EPA emissions testing;
Advantages and disadvantages of setting performance
requirements at 17 percent oxygen instead of normal oxygen as well as
comments on the technically feasible CO emission rates for generators
operating at 17 percent oxygen, for each of the generator categories.
Based on estimates made for EPA, estimated variable costs
for a pressurized oil system would be about $19 for small spark-
ignition engines that that now lack this feature. In the view of the
Directorate for Engineering Sciences, pressurized lubrication systems
would not be necessary to comply with the draft standard. We welcome
comments on this issue.
Whether to exclude portable generators with two-cylinder
Class II engines from the final rule, and if two-cylinder Class II
engines were to be excluded, whether a limit on displacement should be
included to avoid developing a market for small two-cylinder engines
for portable generators that would be exempt from the rule;
Information on the benefits and costs that would be
associated with different CO emission rates;
Information and data about the expected range of
manufacturing variability for CO emissions from EFI equipped small
spark ignited engines, including data on emissions variability from
production target values and expected manufacturing tolerances.
Information about the benefits and costs associated with
altering the performance requirements for CO emissions such that an
alternate performance requirement could be based on limits on those
emissions when the generator is operating in air with reduced oxygen
content of 17 percent oxygen (or a different reduced level) rather than
normal atmospheric oxygen (approximately 20.9 percent), as proposed; if
so, what that performance requirement should be and how should CPSC
should test to verify compliance.
Test methods staff use for determining CO emissions from
generators in normal atmospheric oxygen levels (approximately 20.9
percent) and at reduced oxygen levels (as described in staff's briefing
package), as well information on benefits and costs that could be
associated with requiring those specific methods for evaluation and the
benefits and costs of not requiring a specific test method.
The appropriateness of compliance dates that are one year
from the date of publication of the final rule for portable generators
with Class II engines, or class 2 generators, and three years from the
date of publication of the final rule for generators with handheld and
Class I engines, or handheld generators and class 1 generators.
Whether the Commission should instead adopt a compliance
date that is 18 months from the date of publication of the final rule
for generators with handheld and Class I engines, or handheld
generators and class 1 generators.
Possible alternative technologies that would address the
carbon monoxide hazard associated with portable generators other than
or in addition to reduced carbon monoxide generation, such as, but not
limited to, viable shut-off technology. For any proposed alternate
technology, please provide a description of how its performance would
be characterized, any challenges to implementation, data showing the
viability of the technology in this application and any other
information that would help evaluate the efficacy and cost of the
alternate approach.
The feasibility of continuing to lower in the future the
CO rate requirements for portable generators as technology advances and
whether the Commission can make related findings that CO emission rates
lower than those set forth in the proposed rule will further reduce the
risk of death and injury associated with this hazard. Provide
information on a timetable or other automatic mechanism that would
trigger a review of the emission rates for purposes of evaluating the
feasibility of establishing lower rates as well as any metrics that
would be used to evaluate the state of the technology for the purpose
of lowering the CO rates in the rule.
Potential increase in fuel economy resulting from this
proposed performance standard and quantification of costs or benefits
associated with such increase.
Potential impact of this proposed performance standard on
the market for handheld generators and costs or benefits associated
with such impact.
Potential impact noise emissions associated with this
proposed performance standard and any advantages or disadvantages of
such impact.
The need for retrospective review of this proposed rule,
including the need for development of ex ante criteria, pursuant to the
selection criteria set forth in the Commission's Retrospective Review
Plan. Examples of potential criteria for any future retrospective
review of this proposed rule include, but are not limited to: The
appropriate data points necessary to evaluate such measures, the
appropriate interval for such retrospective review, and the appropriate
goals to define success in each measure.
Additional information on portable generator sales and
use.
Comments should be submitted in accordance with the instructions in
the ADDRESSES section at the beginning of this document.
XIX. Conclusion
For the reasons stated in this preamble, the Commission proposes
requirements for portable generators to address an unreasonable risk of
injury associated with portable generators.
List of Subjects in 16 CFR Part 1241
Consumer protection, Imports, Information, Safety.
For the reasons discussed in the preamble, the Commission proposes
to amend Title 16 of the Code of Federal Regulations as follows:
0
1. Add part 1241 to read as follows:
PART 1241--SAFETY STANDARD FOR PORTABLE GENERATORS
Sec.
1241.1 Scope, purpose and compliance dates.
1241.2 Definitions.
1241.3 Requirements.
1241.4 Test procedures.
1241.5 Prohibited stockpiling.
1241.6 Findings.
Authority: 15 U.S.C. 2056, 2058 and 2076.
Sec. 1241.1 Scope, purpose and compliance dates.
(a) This part 1241, a consumer product safety standard, establishes
[[Page 83612]]
requirements for portable generators, as defined in Sec. 1241.2(b).
The standard includes requirements for carbon monoxide emission rates
for categories of portable generators. These requirements are intended
to reduce an unreasonable risk of injury and death associated with
portable generators.
(b) For purposes of this rule, portable generators include single
phase; 300 V or lower; 60 hertz; portable generators driven by small
handheld and non-handheld (as defined by the Environmental Protection
Agency) spark-ignited utility engines intended for multiple use which
are provided only with receptacle outlets for the AC output circuits
and intended to be moved, though not necessarily with wheels. For
purposes of this rule, portable generators do not include:
(1) Permanently installed generators;
(2) 50 hertz generators;
(3) Marine generators;
(4) Trailer mounted generators;
(5) Generators installed in recreational vehicles;
(6) Generators intended to be pulled by vehicles;
(7) Generators that are part of welding machines;
(8) Generators powered by compression-ignition engines fueled by
diesel.
(c) Class 2 single cylinder and two cylinder generators, as defined
in Sec. 1241.2(c) and (d) manufactured or imported on or after [date
that is 365 days after publication of a final rule] shall comply with
the requirements stated in Sec. 1241.3(b)(2) and (3). Handheld
generators and Class 1 generators, as defined in Sec. 1241.2(a) and
(b), manufactured or imported on or after [date that is 3 years after
publication of a final rule], shall comply with the requirements stated
in Sec. 1241.3(b)(1).
Sec. 1241.2 Definitions.
In addition to the definitions in section 3 of the Consumer Product
Safety Act (15 U.S.C. 2051), the following definitions apply for
purposes of this part 1241.
(a) Handheld generator means a generator powered by a spark ignited
(SI) engine with displacement of 80 cc or less.
(b) Class 1 generator means a generator powered by an SI engine
with displacement greater than 80 cc but less than 225 cc.
(c) Class 2 single cylinder generator means a generator powered by
an SI engine with one cylinder having displacement of 225 cc or
greater, up to a maximum engine power of 25 kW.
(d) Class 2 two cylinder generator means a generator powered by an
SI engine with two cylinders having a total displacement of 225 cc or
greater, up to a maximum engine power of 25 kW.
Sec. 1241.3 Requirements.
(a) When tested in accordance with the test procedures stated in
Sec. 1241.4 (or similar test procedures), all portable generators
covered by this standard shall meet the requirements stated in
paragraph (b) of this section.
(b) Emission rate requirements.
(1) Handheld generators and Class 1 generators must not exceed a
weighted CO emission rate of 75 grams per hour (g/hr).
(2) Class 2 single cylinder generators must not exceed a weighted
CO emission rate of 150 g/hr.
(3) Class 2 two cylinder generators must not exceed a weighted CO
emission rate of 300 g/hr.
Sec. 1241.4 Test procedures.
(a) Any test procedure that will accurately determine the carbon
monoxide emission rate of the portable generator may be used. CPSC uses
the test procedure stated in this section to determine compliance with
the standard.
(b) Definitions.
(1) Load bank and power meter means an AC electric resistor load
bank used to simulate steady electric loads on the generator. The load
bank shall be capable of adjustment to within 5 percent of each
required load condition. A power meter is used to measure the actual
electrical load delivered by the generator with an accuracy of 5 percent.
(2) Fuel and lubricants means fuel and lubricants that meet
manufacturer's specifications for the generator being tested.
(3) Emission measurement system means the constant volume sampling
(CVS) emission measurement system described in 40 CFR parts 1054 and
1065.
(4) Maximum generator load means the maximum output power
capability of the generator assembly as determined by the maximum
generator load determination procedures. The maximum generator load is
used to establish the 6-mode load profile.
(c) Determining maximum generator load.
(1) Power saturation method for conventional (non-inverter)
generator assemblies.
(i) Ensure test facility is at ambient conditions 15-30 [deg]C (60-
85 [deg]F) and approximately 20.9 percent oxygen.
(ii) Apply a load greater than 60 percent of the manufacturer's
rated continuous power for a minimum of 20 minutes to warm the
generator to operating temperature.
(iii) Monitoring voltage and frequency, increase the load applied
to the generator to the maximum observed power output without causing
the voltage or frequency to deviate from the following tolerances:
(A) Voltage Tolerance: 10 percent of the nameplate
rated voltage.
(B) Frequency Tolerance: 5 percent of the nameplate
rated frequency.
(iv) Maintain the maximum observed power output until the operating
temperature of the engine stabilizes. The generator is at stable
operating temperature when the oil temperature varies by less than 2
[deg]C (4 [deg]F) over three consecutive readings taken 15 minutes
apart. For the purpose of determining maximum generator load, if an
overload protection device is present, it shall not activate for a
period of 45 minutes from the initial operating temperature stability
reading. The load may need to be adjusted to maintain the maximum
observed power output while the generator temperatures are stabilizing.
Record voltage, frequency, amperage, power, and oil and ambient air
temperature.
(v) The maximum generator load is the power supplied by the
generator assembly that satisfies the tolerances in paragraph
(c)(1)(iii) of this section when the generator is at stable operating
temperature as defined in paragraph (c)(iv) of this section. Record the
maximum generator load.
(2) Power saturation method for inverter generator assemblies.
(i) Ensure test facility is at ambient conditions 15-30 [deg]C (60-
85 [deg]F) and approximately 20.9 percent oxygen.
(ii) Apply a load greater than 60 percent of the manufacturer's
rated continuous power for a minimum of 20 minutes to warm the
generator to operating temperature.
(iii) Increase the load applied to the generator to the maximum
observed power output.
(iv) Maintain the maximum observed power output until the operating
temperature of the engine stabilizes. The generator is at stable
operating temperature when the oil temperature varies by less than 2
[deg]C (4 [deg]F) over three consecutive readings taken 15 minutes
apart. For the purpose of determining maximum generator load, if an
overload protection device is present, it shall not activate for a
period of 45 minutes from the initial operating temperature stability
reading. The load may need to be adjusted to maintain the maximum
observed power output while the generator temperatures are stabilizing.
Record voltage, frequency, amperage,
[[Page 83613]]
power, and oil and ambient air temperature.
(v) Maximum generator load is the maximum observed power output
that satisfies the criteria defined in paragraph (c)(2)(iv) of this
section. Record the maximum generator load.
(d) Test method to determine the modal CO emission rates of a
portable generator. To determine the weighted CO emission rate of a
portable generator assembly, determine the modal CO emission rates at
six discrete generator loads based on maximum generator load using a
CVS emissions tunnel described in 40 CFR parts 1054 and 1065, and
calculate the weighted CO emission rate. All tests shall be performed
under typical operating conditions at an ambient air temperature of 15-
30 [deg]C (60-85 [deg]F) and approximately 20.9 percent oxygen. Testing
shall be performed on a complete generator assembly and load shall be
applied through the generators receptacle panel. If a generator is
equipped with a system that provides different engine operating modes
such as a fuel economy mode, the generator shall be tested to this
Section in all available modes. CO emission performance shall be
determined by the highest weighted CO emission rate calculated in
paragraph (e) of this section.
(1) Place the generator assembly in front of the CVS tunnel with
the exhaust facing towards the collector. Connect the load bank and
apply a load greater than 60 percent of the manufacturer's rated
continuous power for a minimum of 20 minutes to warm the generator to
operating temperature.
(2) Adjust the load bank to apply the appropriate mode calculated
from the maximum generator load. Modal testing shall be performed in
order from mode 1 to mode 6. Mode points are determined by a percentage
of the maximum generator load:
(i) Mode 1: 100 percent of maximum generator load
(ii) Mode 2: 75 percent of maximum generator load
(iii) Mode 3: 50 percent of maximum generator load
(iv) Mode 4: 25 percent of maximum generator load
(v) Mode 5: 10 percent of maximum generator load
(vi) Mode 6: 0 percent of maximum generator load
(3) Stabilize oil and head temperatures by operating at mode for 5
minutes. After the 5 minute stabilization period, record emissions for
at least 2 minutes at a minimum rate of 0.1 Hz with the prescribed mode
applied. Record the mean CO emission value for that mode during the
data acquisition period.
(4) Repeat steps in paragraphs (d)(2) to (d)(4) for the successive
modes listed in paragraph (d)(2).
(5) When all modal mean CO emission rates have been determined,
calculate and report the weighted CO emission rate using guidance in
paragraph (e).
(e) Weighted CO emission rate calculation and reporting.
(1) Calculate the weighted CO emission rate using the mean CO
emission rates determined in paragraph (d).
mw = 0.09 x m1 + 0.20 x m2 + 0.29 x m3 + 0.30 x m4 + 0.07 x m5 + 0.05 x
m6
Where,
mw = Weighted CO emission Rate (g/hr)
m1 = Mean CO emission Rate at Mode 1 (g/hr)
m2 = Mean CO emission Rate at Mode 2 (g/hr)
m3 = Mean CO emission Rate at Mode 3 (g/hr)
m4 = Mean CO emission Rate at Mode 4 (g/hr)
m5 = Mean CO emission Rate at Mode 5 (g/hr)
m6 = Mean CO emission Rate at Mode 6 (g/hr)
(2) Report the following results for the generator:
(i) Weighted CO emission rate in grams per hour.
(ii) Modal information including the mean CO emission, and head and
oil temperature.
(iii) Maximum generator load information as determined in paragraph
(c). Include maximum generator load, voltage, amperage, and frequency.
Sec. 1241.5 Prohibited stockpiling.
(a) Base period. The base period for portable generators is any
period of 365 consecutive days, chosen by the manufacturer or importer,
in the 5-year period immediately preceding the promulgation of the
final rule.
(b) Prohibited acts. Manufacturers and importers of portable
generators shall not manufacture or import portable generators that do
not comply with the requirements of this part in any 12-month period
between (date of promulgation of the rule) and (effective/compliance
date of the rule) at a rate that is greater than 125% of the rate at
which they manufactured or imported portable generators with engines of
the same class during the base period for the manufacturer.
Sec. 1241.6 Findings.
(b) General. In order to issue a consumer product safety standard
under the Consumer Product Safety Act, the Commission must make certain
findings and include them in the rule. 15 U.S.C. 2058(f)(3). These
findings are discussed in this section.
(c) Degree and nature of the risk of injury. Carbon monoxide is a
colorless, odorless, poisonous gas formed during incomplete combustion
of fossil fuels, such as the fuels used in engines that power portable
generators. Mild CO poisoning symptoms include headaches,
lightheadedness, nausea, and fatigue. More severe CO poisoning can
result in progressively worsening symptoms of vomiting, confusion, loss
of consciousness, coma, and ultimately, death. The high CO emission
rate of current generators can result in situations in which the COHb
levels of exposed individuals rise suddenly and steeply, causing them
to experience rapid onset of confusion, loss of muscular coordination,
and loss of consciousness.
(1) As of May 21, 2015, CPSC databases contained reports of at
least 751 generator-related consumer CO poisoning deaths resulting from
562 incidents, which occurred from 2004 through 2014. Due to incident
reporting delays, statistics for the two most recent years, 2013 and
2014, are incomplete, because data collection is still ongoing, and the
death count most likely will increase in future reports.
(2) Based on NEISS, the Commission estimates that for the 9-year
period of 2004 through 2012, there were 8,703 CO injuries seen in
emergency departments (EDs) associated with portable generators. The
Commission considers this number to represent a lower bound on the true
number of generator-related CO injuries treated in EDs from 2004-2012.
According to Injury Cost Model (ICM) estimates, there were an
additional 16,660 medically-attended CO injuries involving generators
during 2004-2012.
(d) Number of consumer products subject to the rule. For the U.S.
market for the years 2010 through 2014, about 6.9 million gasoline-
powered portable generators were shipped for consumer use, or an
average of about 1.4 million units per year. Shipments of nearly 1.6
million units in 2013 made it the peak year for estimated sales during
this period. Consumer demand for portable generators from year-to-year
fluctuates with major power outages, such as those caused by tropical
or winter storms. Portable generators purchased by consumers and in
household use generally range from under 1 kW of rated power up to
perhaps 15 kW of rated power. In the last 10 to 15 years,
[[Page 83614]]
the U.S. market has shifted towards smaller, less powerful units.
(e) The need of the public for portable generators and the effects
of the rule on their utility, cost, and availability. Portable
generators that are the subject of the proposed standard commonly are
purchased by household consumers to provide electrical power during
emergencies (such as during outages caused by storms), during other
times when electrical power to the home has been shut off, when power
is needed at locations around the home without access to electricity,
and for recreational activities (such as during camping or recreational
vehicle trips).
(1) The proposed rule is based on technically feasible CO emission
rates, so that the function of portable generators is unlikely to be
adversely affected by the rule. There may be an effect on the utility
of portable generators to the extent consumers are unable to purchase
generators due to increased retail prices. There may be a positive
change in utility in terms of fuel efficiency, greater ease of
starting, product quality, and safety of portable generators.
(2) In terms of retail price information, the Commission's review
found that generators with handheld engines ranged in price from $133
to $799, with an average price of about $324. Generators with non-
handheld Class I engines had a wide price range, from $190 to over
$2,000, with an average price of $534. Generators with one-cylinder
Class II engines ranged in price from $329 to $3,999 with an average
price of $1,009. Generators with two-cylinder Class II engines ranged
in price from $1,600 to $4,999 and the average price of these units was
$2,550.
(3) Aggregate estimated compliance costs to manufacturers of
portable generators average approximately $113 per unit for engine and
muffler modifications necessary to comply with the CO emission
requirements of the proposed standard. The net estimated manufacturing
costs per unit to comply with the proposed standard is $114 for
handheld engines, $113 for Class I engines, $110 for Class II, one
cylinder engines, and $138 for Class II, two cylinder engines.
(4) The expected product modifications to produce complying
generators (EFI & catalysts) are available to manufacturers, and the
Commission does not have any indication that firms would exit the
market because of the rule. Therefore, the availability of portable
generators would not likely be affected by the rule.
(f) Other means to achieve the objective of the rule, while
minimizing the impact on competition and manufacturing. The Commission
considered alternatives to achieving the objective of the rule of
reducing unreasonable risks of injury and death associated with
portable generators. For example, the Commission considered less
stringent CO emission rates for portable generators; however, the
Commission found that cost savings from less-stringent CO emission
requirements likely would be less than expected reductions in the
benefits, so that the net benefits of the rule probably would decrease
under this regulatory alternative. The Commission also considered
including an option for reducing CO emissions through use of automatic
shutoff systems, which could potentially reduce the impact of the
proposed rule by providing an additional option for complying with the
proposed rule; however, because of unresolved issues concerning an
automatic shutoff, the Commission does not believe that a regulatory
alternative based on automatic shutoff technology instead of reduced
emissions is feasible for hazard reduction at this time.
(g) Unreasonable risk.
(1) As of May 21, 2015, CPSC databases contained reports of at
least 751 generator-related consumer CO poisoning deaths resulting from
562 incidents, which occurred from 2004 through 2014. Due to incident
reporting delays, statistics for the two most recent years, 2013 and
2014, are incomplete, because data collection is still ongoing, and the
death count most likely will increase in future reports.
(2) Based on NEISS, the Commission estimates that for the 9-year
period of 2004 through 2012, there were 8,703 CO injuries seen in
emergency departments (EDs) associated with portable generators. The
Commission considers this number to represent a lower bound on the true
number of generator-related CO injuries treated in EDs from 2004-2012.
According to Injury Cost Model (ICM) estimates, there were an
additional 16,660 medically-attended CO injuries involving generators
during 2004-2012.
(3) The Commission estimates that the rule would result in
aggregate net benefits of about $145 million annually. On a per-unit
basis, the Commission estimates the present value of the expected
benefits per unit for all units to be $227; the expected costs to
manufacturers plus the lost consumer surplus per unit to be $116; and
the net benefits per unit to be $110. The Commission concludes
preliminarily portable generators pose an unreasonable risk of injury
and finds that the proposed rule is reasonably necessary to reduce that
unreasonable risk of injury.
(g) Public interest. This proposed rule is intended to address an
unreasonable risk of injury and death posed by portable generators. The
Commission believes that adherence to the requirements of the proposed
rule will reduce portable generator deaths and injuries in the future;
thus, the rule is in the public interest.
(h) Voluntary standards. The Commission is aware of two U.S.
voluntary standards that are applicable to portable generators, UL
2201--Safety Standard for Portable Generator Assemblies, and ANSI/PGMA
G300-2015--Safety and Performance of Portable Generators. These
standards include the same requirements set forth mandatory CPSC
portable generator label but do not otherwise address the risks related
to CO poisoning. The Commission does not believe the standards are
adequate because they fail to address the risk of CO hazard beyond the
CPSC mandatory labeling requirement. The Commission is unaware of any
portable generator that has been certified to either of the standards,
and as such it is unlikely whether there would be substantial
compliance with it if CO emissions requirements were incorporated.
(i) Relationship of benefits to costs. The aggregate annual
benefits and costs of the rule are estimated to be about $298 million
and $153 million, respectively. Aggregate net benefits from the rule,
therefore, are estimated to be about $145 million annually. On a per
unit basis, the Commission estimates the present value of the expected
benefits per unit for all units to be $227. The Commission estimates
the expected costs to manufacturers plus the lost consumer surplus per
unit to be $116. Based on this analysis, the Commission finds
preliminary that the benefits expected from the rule bear a reasonable
relationship to the anticipated costs of the rule.
(j) Least burdensome requirement that would adequately reduce the
risk of injury. (1) The Commission considered less-burdensome
alternatives to the proposed rule on portable generators, but concluded
preliminary that none of these alternatives would adequately reduce the
risk of injury.
(2) The Commission considered not issuing a mandatory rule, but
instead relying upon voluntary standards. As discussed previously, the
Commission does not believe that either voluntary standard adequately
addresses the CO risk of injury and death associated with portable
generators. Furthermore, the Commission doubts that either of the
[[Page 83615]]
voluntary standards would have substantial compliance by industry.
(3) Excluding portable generators with two cylinder, Class II
engines from the scope of the rule. The Commission estimates that net
benefits of the proposed rule range from about $100 to about $140 per
generator for the models with handheld, Class I and one-cylinder Class
II engines. However, net benefits were negative $135 for the models
with two-cylinder class II engines. Consequently, excluding portable
generators with two cylinder Class II engines would result in a less
burdensome alternative. However, it is possible that exclusion of
generators with two-cylinder Class II engines from the scope of the
rule could create an economic incentive for manufacturers of generators
with larger one-cylinder engines to either switch to two-cylinder
engines for those models, or if they already have two-cylinder models
in their product lines, they could be more likely to drop larger one-
cylinder models from their product lines. Because the Commission lacks
more specific information on the generators with Class II twin cylinder
engines, the Commission is proposing this rule with the broader scope
of including these generators.
(4) The Commission considered higher allowable CO emission rates,
which might result in costs savings from lower costs associated with
catalysts (if they would not be required, or if less-costly materials
could suffice), less-extensive engine modifications (other than EFI-
related costs) and less-extensive generator housing modifications (if
housing enlargement and other retooling would be minimized). However,
based on Commission estimates, it seems likely that cost savings from
less-stringent CO emission requirements would be less than expected
reductions in benefits. Therefore, the Commission is not proposing this
less burdensome alternative.
Dated: November 3, 2016.
Todd A. Stevenson,
Secretary, Consumer Product Safety Commission.
[FR Doc. 2016-26962 Filed 11-18-16; 8:45 am]
BILLING CODE 6355-01-P