[Federal Register Volume 76, Number 12 (Wednesday, January 19, 2011)]
[Proposed Rules]
[Pages 3422-3449]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-917]
[[Page 3421]]
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Part V
Environmental Protection Agency
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40 CFR Part 180
Sulfuryl Fluoride; Proposed Order Granting Objections to Tolerances and
Denying Request for a Stay; Proposed Rule
Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 /
Proposed Rules
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2005-0174; FRL-8857-9]
Sulfuryl Fluoride; Proposed Order Granting Objections to
Tolerances and Denying Request for a Stay
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed Order.
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SUMMARY: In this document, EPA is making available its proposed
resolution of objections and a stay request with regard to sulfuryl
fluoride and fluoride tolerances promulgated in 2004 and 2005 under
section 408(d) of the Federal Food, Drug, and Cosmetic Act (FFDCA). The
objections and stay request were filed by the Fluoride Action Network,
the Environmental Working Group, and Beyond Pesticides. Notwithstanding
the fact that this document is a proposed resolution, and regulatory
assessment requirements do not apply, EPA is inviting public comment on
all aspects of the proposed resolution of objections, including the
underlying scientific evaluations.
DATES: Comments must be received on or before April 19, 2011.
ADDRESSES: Submit your comments, identified by docket identification
(ID) number EPA-HQ-OPP-2005-0174, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket Facility's normal hours of operation (8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays).
Special arrangements should be made for deliveries of boxed
information. The Docket Facility telephone number is (703) 305-5805.
Instructions: Direct your comments to docket ID number EPA-HQ-OPP-
2005-0174. EPA's policy is that all comments received will be included
in the docket without change and may be made available on-line at
http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through regulations.gov or e-
mail. The regulations.gov Web site is an ``anonymous access'' system,
which means EPA will not know your identity or contact information
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through regulations.gov,
your e-mail address will be automatically captured and included as part
of the comment that is placed in the docket and made available on the
Internet. If you submit an electronic comment, EPA recommends that you
include your name and other contact information in the body of your
comment and with any disk or CD-ROM you submit. If EPA cannot read your
comment due to technical difficulties and cannot contact you for
clarification, EPA may not be able to consider your comment. Electronic
files should avoid the use of special characters, any form of
encryption, and be free of any defects or viruses.
Docket: All documents in the docket are listed in the docket index
available at http://www.regulations.gov. Although listed in the index,
some information is not publicly available, e.g., CBI or other
information whose disclosure is restricted by statute. Certain other
material, such as copyrighted material, is not placed on the Internet
and will be publicly available only in hard copy form. Publicly
available docket materials are available either in the electronic
docket at http://www.regulations.gov, or, if only available in hard
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of
operation of this Docket Facility are from 8:30 a.m. to 4 p.m., Monday
through Friday, excluding legal holidays. The Docket Facility telephone
number is (703) 305-5805.
FOR FURTHER INFORMATION CONTACT: Meredith Laws, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: 703-308-7038; e-mail address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this action apply to me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, pesticide manufacturer, or
consumer. Potentially affected entities may include, but are not
limited to:
Food manufacturing (NAICS code 311), e.g., grain and
oilseed milling; animal food manufacturing; flour milling; bread and
bakery product manufacturing; cookie, cracker, and pasta manufacturing;
snack food manufacturing.
Pesticide manufacturing (NAICS code 32532), e.g.,
pesticide manufacturers; commercial applicators.
Community Food Services (NAICS code 624210), e.g., food
banks.
Farm Product Warehousing and Storage (NAICS code 493130),
e.g., grain elevators, private and public food warehousing and storage.
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in this unit could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether this action might apply to certain entities. If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.
B. What should I consider as I prepare my comments for EPA?
1. Submitting CBI. Do not submit this information to EPA through
regulations.gov or e-mail. Clearly mark the part or all of the
information that you claim to be CBI. For CBI information in a disk or
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as
CBI and then identify electronically within the disk or CD-ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
2. Tips for preparing your comments. When submitting comments,
remember to:
i. Identify the document by docket ID number and other identifying
information (subject heading, Federal Register date and page number).
ii. Follow directions. The Agency may ask you to respond to
specific questions or organize comments by referencing a Code of
Federal Regulations (CFR) part or section number.
[[Page 3423]]
iii. Explain why you agree or disagree; suggest alternatives and
substitute language for your requested changes.
iv. Describe any assumptions and provide any technical information
and/or data that you used.
v. If you estimate potential costs or burdens, explain how you
arrived at your estimate in sufficient detail to allow for it to be
reproduced.
vi. Provide specific examples to illustrate your concerns and
suggest alternatives.
vii. Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
viii. Make sure to submit your comments by the comment period
deadline identified.
C. What are the acronyms used in this order?
The following is a list of acronyms used in this order:
CAA--Clean Air Act
CAAA--Clean Air Act Amendments of 1990
CSFII--Continuing Survey of Food Intakes by Individuals
CUE--Critical Use Exemption
EPA--Environmental Protection Agency
FACA--Federal Advisory Committee Act
FAN--Fluoride Action Network
FDA--Food and Drug Administration
FIFRA--Federal Insecticide, Fungicide, and Rodenticide Act
FFDCA--Federal Food, Drug, and Cosmetic Act
FQPA--Food Quality Protection Act of 1996
IOM--Institute of Medicine
L--liter
LOAEL--Lowest Observed Adverse Effect Level
MCL--Maximum contaminant level
MCLG--Maximum contaminant level goal
mg--milligram
MOE--Margin of Exposure
MRID--Master Record Identification
NAS--National Academy of Sciences
NOAEL--No Observed Adverse Effect Level
NPDWR--National Public Drinking Water Regulations
NRC--National Research Council
NRDC--Natural Resources Defense Council
OPP--EPA's Office of Pesticide Programs
OW--EPA's Office of Water
PAD--Population Adjusted Dose
ppm--parts per million
RED--Reregistration Eligibility Decision
RfD--Reference Dose
SDWA--Safe Drinking Water Act
SMCL--Secondary maximum contaminant level
SOP--Standard Operating Procedure
USDA--United States Department of Agriculture
II. Introduction
A. What action is the agency taking?
In this document, EPA is making available for comment a proposed
order granting objections and denying a stay request with regard to
tolerances established for sulfuryl fluoride and fluoride in 2004 (69
FR 3240, January 23, 2004) (FRL-7342-1) and 2005 (70 FR 40899, July 15,
2005) (FRL-7723-7) under FFDCA section 408 (21 U.S.C. 346a). (See 40
CFR 180.145(c); 180.575). These objections were first filed by the
Fluoride Action Network (FAN) and Beyond Pesticides/National Coalition
Against the Misuse of Pesticides. (Ref. 1). FAN and Beyond Pesticides
also requested a hearing on their objections. At a later date, FAN and
Beyond Pesticides were joined by the Environmental Working Group
(hereinafter the three parties are referred to as ``the Objectors'')
(Refs. 2 and 3). The Objectors argue that the sulfuryl fluoride and
fluoride tolerances should not have been established by EPA because
aggregate exposure to fluoride is unsafe under FFDCA section 408. The
stay request as to the tolerances was filed by the Objectors in June,
2006, following release of a report by the National Research Council
(NRC) of the National Academy of Sciences (NAS) concerning the risk of
fluoride. (71 FR 38125, July 5, 2006) (FRL-8075-6).
After reviewing the objections and the NRC Report, EPA is proposing
to grant the objections because it agrees that aggregate exposure to
fluoride for certain major identifiable population subgroups does not
meet the safety standard in FFDCA section 408. Because EPA is proposing
to grant the Objectors' objections a hearing is not warranted. Finally,
EPA is proposing to deny the Objectors' request for a stay because the
risks from continued sulfuryl fluoride use in the short term is
insignificant while the environmental and economic consequences from a
sudden withdrawal of sulfuryl fluoride, a methyl bromide replacement,
are considerable.
B. What is the agency's authority for taking this action?
The procedure for filing objections to tolerance actions and EPA's
authority for acting on such objections is contained in section 408(g)
of FFDCA (21 U.S.C. 346a(g)) and regulations at 40 CFR part 178. That
same authority governs hearing and stay requests.
III. Statutory and Regulatory Background
In this Unit, EPA provides background on the relevant statutes and
regulations governing the Objectors' objections, requests for hearing,
and request for a stay as well as on pertinent Agency policies and
practices.
Unit III.A. summarizes the requirements and procedures in section
408 of FFDCA and applicable regulations pertaining to pesticide
tolerances, including the procedures for objecting to EPA tolerance
actions and the substantive standards for evaluating the safety of
pesticide tolerances. This unit also discusses the closely-related
statute under which EPA regulates the sale, distribution, and use of
pesticides, the Federal Insecticide, Fungicide, and Rodenticide Act
(FIFRA) (7 U.S.C. 136 et seq.).
Unit III.B. provides an overview of the risk assessment process
followed by EPA's Office of Pesticide Programs (OPP). It contains an
explanation of how EPA identifies the hazards posed by pesticides, how
EPA determines the level of exposure to pesticides that pose a concern
(level of concern), how EPA measures human exposure to pesticides, and
how hazard, level of concern conclusions, and human exposure estimates
are combined to evaluate risk. Further, this unit presents background
information on two Agency policies with particular relevance to this
action.
Unit III.C. provides a brief overview of the Safe Drinking Water
Act (SDWA) and the Montreal Protocol on Substances that Deplete the
Ozone Layer (Montreal Protocol) and Title VI of the Clean Air Act (CAA)
addressing Stratospheric Ozone Protection. These statutory schemes and
international treaty are relevant to this proceeding because EPA
regulates fluoride, a sulfuryl fluoride degradate, under SDWA, and
because sulfuryl fluoride has played an important role in the United
States fulfilling its obligations under the Montreal Protocol and CAA.
Specifically, sulfuryl fluoride is a substitute for the ozone-depleting
pesticide, methyl bromide.
A. FFDCA/FIFRA and Applicable Regulations
1. In general. EPA establishes maximum residue limits, or
``tolerances,'' for pesticide residues in food under section 408 of
FFDCA. (21 U.S.C. 346a). Without such a tolerance or an exemption from
the requirement of a tolerance, a food containing a pesticide residue
is ``adulterated'' under section 402 of FFDCA and may not be legally
moved in interstate commerce. (21 U.S.C. 331, 342). Monitoring and
enforcement of pesticide tolerances are carried out by the U.S. Food
and Drug Administration (FDA) and the U.S. Department of Agriculture
(USDA). Section 408 was substantially rewritten by the Food Quality
Protection Act of 1996 (FQPA), which added the provisions establishing
a detailed safety standard for pesticides, additional protections for
infants and children, and the estrogenic substances screening
[[Page 3424]]
program. (Pub. L. 104-170, 110 Stat. 1489 (1996)).
EPA also regulates pesticides under FIFRA (7 U.S.C. 136 et seq.).
While FFDCA authorizes the establishment of legal limits for pesticide
residues in food, FIFRA requires the approval of pesticides prior to
their sale and distribution, (7 U.S.C. 136a(a)), and establishes a
registration regime for regulating the use of pesticides. FIFRA
regulates pesticide use in conjunction with its registration scheme by
requiring EPA review and approval of pesticide labeling and specifying
that use of a pesticide inconsistent with its labeling is a violation
of Federal law. (7 U.S.C. 136j(a)(2)(G)). In the FQPA, Congress
integrated action under the two statutes by requiring that the safety
standard under FFDCA be used as a criterion in FIFRA registration
actions as to pesticide uses which result in dietary risk from residues
in or on food, (7 U.S.C. 136(bb)), and directing that EPA coordinate,
to the extent practicable, revocations of tolerances with pesticide
cancellations under FIFRA. (21 U.S.C. 346a(l)(1)).
2. Safety standard for pesticide tolerances. A pesticide tolerance
may only be promulgated by EPA if the tolerance is ``safe.'' (21 U.S.C.
346a(b)(2)(A)(i)). ``Safe'' is defined by the statute to mean that
``there is a reasonable certainty that no harm will result from
aggregate exposure to the pesticide chemical residue, including all
anticipated dietary exposures and all other exposures for which there
is reliable information.'' (21 U.S.C. 346a(b)(2)(A)(ii)). Section
408(b)(2)(D) directs EPA, in making a safety determination, to:
Consider, among other relevant factors--* * *
* * *available information concerning the aggregate exposure levels
of consumers (and major identifiable subgroups of consumers) to the
pesticide chemical residue and to other related substances,
including dietary exposure under the tolerance and all other
tolerances in effect for the pesticide chemical residue, and
exposure from other non-occupational sources.* * *
(21 U.S.C. 346a(b)(2)(D)(v), (vi) and (viii)). EPA must also consider,
in evaluating the safety of tolerances, ``safety factors which * * *
are generally recognized as appropriate for the use of animal
experimentation data.'' (21 U.S.C. 346a(b)(2)(D)(ix).
Risks to infants and children are given special consideration.
Specifically, section 408(b)(2)(C)(i)(II) requires that EPA assess the
risk to pesticides based on ``available information concerning the
special susceptibility of infants and children to the pesticide
chemical residues, including neurological differences between infants
and children and adults, and effects of in utero exposure to pesticide
chemicals.* * * '' (21 U.S.C. 346a(b)(2)(C)(i)(II)). This provision
also creates a presumption that EPA will use an additional safety
factor for the protection of infants and children. Specifically, it
directs that ``[i]n the case of threshold effects, * * * an additional
tenfold margin of safety for the pesticide chemical residue and other
sources of exposure shall be applied for infants and children to take
into account potential pre- and post-natal toxicity and completeness of
the data with respect to exposure and toxicity to infants and
children.'' (21 U.S.C. 346a(b)(2)(C)). EPA is permitted to ``use a
different margin of safety for the pesticide chemical residue only if,
on the basis of reliable data, such margin will be safe for infants and
children.'' (Id.). The additional safety margin for infants and
children is referred to throughout this Order as the ``children's
safety factor.''
3. Procedures for establishing, amending, or revoking tolerances.
Tolerances are established, amended, or revoked by rulemaking under the
unique procedural framework set forth in FFDCA. Generally, a tolerance
rulemaking is initiated by the party seeking to establish, amend, or
revoke a tolerance by means of filing a petition with EPA. (See 21
U.S.C. 346a(d)(1)). EPA publishes in the Federal Register a notice of
the petition filing and requests public comment. (21 U.S.C.
346a(d)(3)). After reviewing the petition, and any comments received on
it, EPA may issue a final rule establishing, amending, or revoking the
tolerance, issue a proposed rule to do the same, or deny the petition.
(21 U.S.C. 346a(d)(4)).
Once EPA takes final action on the petition by either establishing,
amending, or revoking the tolerance or denying the petition, any person
may file objections with EPA and seek an evidentiary hearing on those
objections. (21 U.S.C. 346a(g)(2)). Objections and hearing requests
must be filed within 60 days. (Id.). The statute provides that EPA
shall ``hold a public evidentiary hearing if and to the extent the
Administrator determines that such a public hearing is necessary to
receive factual evidence relevant to material issues of fact raised by
the objections.'' (21 U.S.C. 346a(g)(2)(B)). EPA regulations make clear
that hearings will only be granted where it is shown that there is ``a
genuine and substantial issue of fact,'' the requestor has identified
evidence ``which, if established, resolve one or more of such issues in
favor of the requestor,'' and the issue is ``determinative'' with
regard to the relief requested. (40 CFR 178.32(b)). EPA's final order
on the objections and requests for hearing is subject to judicial
review. (21 U.S.C. 346a(h)(1)). The statute directs that tolerance
regulations shall take effect upon publication unless EPA specifies
otherwise. (40 U.S.C. 346a(g)(1)). EPA is authorized to stay the
effectiveness of the tolerance if objections are filed. (Id.).
B. EPA Risk Assessment for Tolerances--Policy and Practice
1. The safety determination--risk assessment. To assess risk of a
pesticide tolerance, EPA combines information on pesticide toxicity
with information regarding the route, magnitude, and duration of
exposure to the pesticide. The risk assessment process involves four
distinct steps:
(1) Identification of the toxicological hazards posed by a
pesticide;
(2) Determination of the ``level of concern'' with respect to human
exposure to the pesticide;
(3) Estimation of human exposure to the pesticide; and
(4) Characterization of risk posed to humans by the pesticide based
on comparison of human exposure to the level of concern.
a. Hazard identification. In evaluating toxicity or hazard, EPA
reviews toxicity data, typically from studies with laboratory animals,
to identify any adverse effects on the test subjects. Where available
and appropriate, EPA will also take into account studies involving
humans, including human epidemiological studies. For most pesticides,
the animal toxicity database usually consists of studies investigating
a broad range of endpoints including gross and microscopic effects on
organs and tissues, functional effects on bodily organs and systems,
effects on blood parameters (such as red blood cell count, hemoglobin
concentration, hematocrit, and a measure of clotting potential),
effects on the concentrations of normal blood chemicals (including
glucose, total cholesterol, urea nitrogen, creatinine, total protein,
total bilirubin, albumin, hormones, and enzymes such as alkaline
phosphatase, alanine aminotransfersase and cholinesterases), and
behavioral or other gross effects identified through clinical
observation and measurement. EPA examines whether adverse effects are
caused by different durations of exposure ranging from short-term
(acute) to long-term (chronic) pesticide exposure and different routes
of exposure (oral, dermal, inhalation). Further, EPA evaluates
potential adverse effects in
[[Page 3425]]
different age groups (adults as well as fetuses and juveniles). (Ref. 4
at 8-10).
EPA also considers whether the adverse effect has a threshold--a
level below which exposure has no appreciable chance of causing the
adverse effect. For effects that have no threshold, EPA assumes that
any exposure to the substance increases the risk that the adverse
effect may occur.
b. Level of concern/dose-response analysis. Once a pesticide's
potential hazards are identified, EPA determines a toxicological level
of concern for evaluating the risk posed by human exposure to the
pesticide. In this step of the risk assessment process, EPA essentially
evaluates the levels of exposure to the pesticide at which effects
might occur. An important aspect of this determination is assessing the
relationship between exposure (dose) and response (often referred to as
the dose-response analysis). EPA follows differing approaches to
identifying a level of concern for threshold and non-threshold hazards.
i. Threshold effects. In examining the dose-response relationship
for a pesticide's threshold effects, EPA evaluates an array of toxicity
studies on the pesticide. In each of these studies, EPA attempts to
identify the lowest observed adverse effect level (LOAEL) and the no
observed adverse effect level (NOAEL), which by definition is the next
lower tested dose level below the LOAEL. Generally, EPA will use the
lowest NOAEL from the available studies as a starting point (called
``the Point of Departure'') in estimating the level of concern for
humans. (Ref. 4 at 9 (The Point of Departure ``is simply the toxic dose
that serves as the `starting point' in extrapolating a risk to the
human population.'')). At times, however, EPA will use a LOAEL from a
study as the Point of Departure when no NOAEL is identified in that
study and the LOAEL is close to, or lower than, other relevant NOAELs.
The Point of Departure is in turn used in choosing a level of concern.
EPA will make separate determinations as to the Points of Departure,
and correspondingly levels of concern, for both short and long exposure
periods as well as for the different routes of exposure (oral, dermal,
and inhalation).
In recent years, EPA has increasingly used a more scientifically
sophisticated approach to choosing the Point of Departure. This
approach, called a benchmark dose, or BMD, estimates a point along a
dose-response curve that corresponds to a specific response level.
(Ref. 5). For example, a BMD10 represents a 10% change from
the background or typical value for the response of concern. In
contrast to the NOAEL/LOAEL approach, a BMD is calculated using a range
of dose response data and thus better accounts for the variability and
uncertainty in the experimental results due to characteristics of the
study design, such as dose selection, dose spacing, and sample size. In
addition to a BMD, EPA generally also calculates a ``confidence limit''
in the BMD. Confidence limits express the uncertainty in a BMD that may
be due to sampling and/or experimental error. The lower confidence
limit on the dose used as the BMD is termed the BMDL, which the Agency
often uses as the Point of Departure. Use of the BMDL for deriving the
Point of Departure rewards better experimental design and procedures
that provide more precise estimates of the BMD, resulting in tighter
confidence intervals. It also provides a health protective conservative
estimate of the safe dose. Numerous scientific peer review panels over
the last decade have supported the Agency's application of the BMD
approach as a scientifically supportable method for deriving Points of
Departure in human health risk assessment, and as an improvement over
the historically applied approach of using NOAELs or LOAELs. (Refs. 6
and 7).
In estimating and describing the level of concern, the Point of
Departure is at times used differently depending on whether the risk
assessment addresses dietary or non-dietary exposures. For dietary
risks, EPA uses the Point of Departure to calculate an acceptable level
of exposure or reference dose (RfD). The RfD is calculated by dividing
the Point of Departure by all applicable safety or uncertainty factors.
Typically, EPA uses a baseline safety/uncertainty factor of 100X in
assessing pesticide risk. That value includes a factor of 10 (10X)
where EPA is using data from laboratory animals to account for the
possibility that humans potentially have greater sensitivity to the
pesticide than animals and another factor of 10X to account for
potential variations in sensitivity among members of the human
population. Additional safety factors may be added to address data
deficiencies or concerns raised by the existing data. Under the FQPA,
an additional safety factor of 10X is presumptively applied to protect
infants and children, unless reliable data support selection of a
different factor. This FQPA additional safety factor largely replaces
pre-FQPA EPA practice regarding additional safety factors. (Ref. 8 at
4-11).
In implementing FFDCA section 408, EPA's Office of Pesticide
Programs, also calculates a variant of the RfD referred to as a
Population Adjusted Dose (PAD). APAD is the RfD divided by any portion
of the FQPA safety factor that does not correspond to one of the
traditional additional safety factors used in general Agency risk
assessments. (Id. at 13-16). The reason for calculating PADs is so that
other parts of the Agency, which are not governed by FFDCA section 408,
can, when evaluating the same or similar substances, easily identify
which aspects of a pesticide risk assessment are a function of the
particular statutory commands in FFDCA section 408. Today, RfDs and
PADs are generally calculated for both acute and chronic dietary risks
although traditionally RfDs and PADs were only calculated for chronic
risks. Throughout this document general references to OPP's calculated
safe dose are denoted as an RfD/PAD.
For non-dietary, and combined dietary and non-dietary, risk
assessments of threshold effects, the toxicological level of concern is
not expressed as an RfD/PAD but rather in terms of an acceptable (or
target) margin of exposure (MOE) between human exposure and the Point
of Departure. The ``margin'' of interest is the ratio between human
exposure and the Point of Departure which is calculated by dividing
human exposure into the Point of Departure. An acceptable MOE is
generally considered to be a margin at least as high as the product of
all applicable safety factors for a pesticide. For example, if a
pesticide needs a 10X factor to account for potential inter-species
differences, 10X factor for potential intra-species differences, and
10X factor for the FQPA children's safety provision, the safe or target
MOE would be a MOE of at least 1,000. What that means is that for the
pesticide in the example to meet the safety standard, human exposure to
the pesticide would generally have to be at least 1,000 times smaller
than the Point of Departure. Like RfD/PADs, specific target MOEs are
selected for exposures of different durations. For non-dietary
exposures, EPA typically examines short-term, intermediate-term, and
long-term exposures. Additionally, target MOEs may be selected based on
both the duration of exposure and the various routes of non-dietary
exposure--dermal, inhalation, and oral.
ii. Non-threshold effects. For risk assessments for non-threshold
effects, EPA does not use the RfD/PAD or MOE approach to choose a level
of concern if quantification of the risk is deemed appropriate. Rather,
EPA calculates the slope of the dose-response curve for the non-
threshold effects from relevant
[[Page 3426]]
studies frequently using a linear, low-dose extrapolation model that
assumes that any amount of exposure will lead to some degree of risk.
This dose-response analysis will be used in the risk characterization
stage to estimate the risk to humans of the non-threshold effect.
c. Estimating human exposure. Risk is a function of both hazard and
exposure. Thus, equally important to the risk assessment process as
determining the hazards posed by a pesticide and the toxicological
level of concern for those hazards is estimating human exposure. Under
FFDCA section 408, EPA is concerned not only with exposure to pesticide
residues in food but also exposure resulting from pesticide
contamination of drinking water supplies and from use of pesticides in
the home or other non-occupational settings. (See 21 U.S.C.
346a(b)(2)(D)(vi)). Additionally, EPA must take into account non-
occupational exposure from ``other related substances.'' (Id.).
i. Exposure from food. There are two critical variables in
estimating exposure in food:
The types and amount of food that is consumed; and
The residue level in that food.
Consumption is estimated by EPA based on scientific surveys of
individuals' food consumption in the United States conducted by the
USDA. (Ref. 4 at 12). Information on residue values comes from a range
of sources including crop field trials, data on pesticide reduction (or
concentration) due to processing, cooking, and other practices,
information on the extent of usage of the pesticide, and monitoring of
the food supply. (Id. at 17).
In assessing exposure from pesticide residues in food, EPA, for
efficiency's sake, follows a tiered approach in which it, in the first
instance, assesses exposure using the worst case assumptions that 100%
of the crop or commodity in question is treated with, or exposed to,
the pesticide and 100% of the food from that crop or commodity contains
pesticide residues at the tolerance level. (Id. at 11). When such an
assessment shows no risks of concern, a more complex risk assessment is
unnecessary. By avoiding a more complex risk assessment, EPA's
resources are conserved and regulated parties are spared the cost of
any additional studies that may be needed. If, however, a first tier
assessment suggests there could be a risk of concern, EPA then attempts
to refine its exposure assumptions to yield a more realistic picture of
residue values through use of data on the percent of the crop or
commodity actually treated with, or exposed to, the pesticide and data
on the level of residues that may be present on the treated crop or
commodity. These latter data are used to estimate what has been
traditionally referred to by EPA as ``anticipated residues.''
Use of percent crop/commodity treated data and anticipated residue
information is appropriate because EPA's worst-case assumptions of 100%
treatment and residues at tolerance value significantly overstate
residue values. There are several reasons why this is true. First, all
growers of a particular crop would rarely choose to apply the same
pesticide to that crop (some may apply no pesticide; some may apply an
alternative pesticide); generally, the proportion of the crop treated
with a particular pesticide is significantly below 100%. (70 FR 46706,
46731, August 10, 2005) (FRL-7727-4). This is true with food and
structural fumigants such as sulfuryl fluoride as well, especially with
regard to the structural fumigant use in food processing facilities
because such use incurs infrequently and only potentially affects a
small portion of the food processed in the facility. Second, the
tolerance value represents a high end or worst case value. Tolerance
values are chosen only after EPA has evaluated data from experimental
trials in which the pesticide has been used in a manner, consistent
with the draft FIFRA label, that is likely to produce the highest
residue in the crop or food in question (e.g., maximum application
rate, maximum number of applications, minimum pre-harvest interval
between last pesticide application and harvest). (Refs. 4 and 9). These
experimental trials are generally conducted in several locations and
involve multiple samples. (Id. at 5, 7 and Tables 1 and 5). The results
from such experimental trials invariably show that the residue levels
for a given pesticide use will vary from as low as non-detectable to
measurable values in the parts per million (ppm) range with the
majority of the values falling at the lower part of the range. (70 FR
46731) (FRL-7727-4). EPA uses a statistical procedure to analyze the
experimental trial results and identify the upper bound of expected
residue values. This upper bound value is typically used as the
tolerance value. (Ref. 10). There may be some commodities from a
treated crop or commodity that approach the tolerance value where the
maximum label rates are followed, but most generally fall significantly
below the tolerance value. If less than the maximum legal rate is
applied, residues will be even lower. Third, residue values measured at
the time of treatment do not take into account the lowering of residue
values that frequently occurs as a result of degradation over time and
through food processing and cooking.
EPA uses several techniques to refine residue value estimates.
(Ref. 4 at 17-28). First, where appropriate, EPA will take into account
all the residue values reported in the experimental trials, either
through use of an average or individually. Second, EPA will consider
data showing what portion of the crop or commodity is not treated with,
or exposed to, the pesticide. Third, data can be produced showing
pesticide degradation and decline over time, and the effect of
commercial and consumer food handling and processing practices.
Finally, EPA can consult monitoring data gathered by the FDA, the USDA,
or pesticide registrants, on pesticide levels in food at points in the
food distribution chain distant from the farm, including retail food
establishments.
Another critical component of the exposure assessment is how data
on consumption patterns are combined with data on pesticide residue
levels in food. Traditionally, EPA has calculated exposure by simply
multiplying average consumption by average residue values for
estimating chronic risks and high-end consumption by maximum residue
values for estimating acute risks. Using average residues is a
realistic approach for chronic risk assessment due to the fact that
variations in residue levels and consumption amounts average out over
time especially given the nationwide market for food in the United
States. Using average values is inappropriate for acute risk
assessments, however, because in assessing acute exposure situations it
matters how much of each treated food a given consumer eats in the
short-term and what the residue levels are in the particular foods
consumed. Yet, using maximum residue values for acute risk assessment
tends to greatly overstate exposure because it is unlikely that a
person would consume at a single meal multiple food components bearing
high-end residues. To take into account the variations in short-term
consumption patterns and food residue values for acute risk
assessments, EPA uses probabilistic modeling techniques for estimating
exposure when more simplistic models appear to show risks of concerns.
All of these refinements to the exposure assessment process, from
use of food monitoring data through probabilistic modeling, can have
dramatic effects on the level of exposure
[[Page 3427]]
predicted, typically reducing worst case estimates by at least 1 or 2
orders of magnitude. (Ref. 11 at 16-17; 70 FR 46706, 46732, August 10,
2005) (FRL-7727-4).
ii. Exposure from water. EPA may use either or both field
monitoring data and mathematical water exposure models to generate
pesticide exposure estimates in drinking water. Monitoring and modeling
are both important tools for estimating pesticide concentrations in
water and can provide different types of information. Monitoring data
can provide estimates of pesticide concentrations in water that are
representative of specific agricultural or residential pesticide
practices and under environmental conditions associated with a sampling
design. Although monitoring data can provide a direct measure of the
concentration of a pesticide in water, it does not always provide a
reliable estimate of exposure because sampling may not occur in areas
with the highest pesticide use, and/or the sampling may not occur when
the pesticides are being used.
In estimating pesticide exposure levels in drinking water, EPA most
frequently uses mathematical water exposure models. EPA's models are
based on extensive monitoring data and detailed information on soil
properties, crop characteristics, and weather patterns. (69 FR 30042,
30058-30065, May 26, 2004) (FRL-7355-7). These models calculate
estimated environmental concentrations of pesticides using laboratory
data that describe how fast the pesticide breaks down to other
chemicals and how it moves in the environment. These concentrations can
be estimated continuously over long periods of time, and for places
that are of most interest for any particular pesticide. Modeling is a
useful tool for characterizing vulnerable sites, and can be used to
estimate peak concentrations from infrequent, large storms.
Unlike assessments of exposure to pesticides in food, assessments
of exposure to pesticides in drinking water conducted under FIFRA and
FFDCA section 408 do not assume there is a nationwide market for
drinking water. A person's source of drinking water is primarily local
and often the pesticide use is quite localized as well. Thus, generally
EPA assesses drinking water exposure to pesticides under FIFRA and
FFDCA section 408 based on the most vulnerable watersheds and not on a
national or even regional average. (See 74 FR 59608, 59618-59619,
59658, November 18, 2009) (FRL-8797-6). Further, these assessments
commonly use high-end residue estimates from models and assume average
consumption levels.
In the case of fluoride, however, the primary source of exposure is
not from pesticide use. Additionally, as described in Unit V.A.2., EPA
has an extensive monitoring database from across the United States on
fluoride levels in drinking water. These factors have been taken into
account in how EPA has conducted its FFDCA section 408 risk assessment
for fluoride.
d. Risk characterization. The final step in the risk assessment is
risk characterization. In this step, EPA combines information from the
first three steps (hazard identification, level of concern/dose-
response analysis, and human exposure assessment) to quantitatively
estimate the risks posed by a pesticide. Separate characterizations of
risk are conducted for different durations of exposure. Additionally,
separate and, where appropriate, aggregate characterizations of risk
are conducted for the different routes of exposure (dietary and non-
dietary).
For threshold risks, EPA estimates risk in one of two ways. Where
EPA has calculated a RfD/PAD, risk is estimated by expressing human
exposure as a percentage of the RfD/PAD. Exposures lower than 100% of
the RfD/PAD are generally not of concern. Alternatively, EPA may
express risk by comparing the MOE between estimated human exposure and
the Point of Departure with the acceptable or target MOE. As described
previously, the acceptable or target MOE is the product of all
applicable safety factors. To calculate the actual MOE for a pesticide,
estimated human exposure to the pesticide is divided into the Point of
Departure. In contrast to the RfD/PAD approach, higher MOEs denote
lower risk. Accordingly, if the target MOE for a pesticide is 100, MOEs
equal to or exceeding 100 would generally not be of concern.
As a conceptual matter, the RfD/PAD and MOE approaches are
fundamentally equivalent. For a given risk and given exposure of a
pesticide, if exposure to a pesticide were found to be acceptable under
an RfD/PAD analysis it would also pass under the MOE approach, and
vice-versa. However, for any specific pesticide, risk assessments for
different exposure durations or routes may yield different results.
This is a function not of the choice of the RfD/PAD or MOE approach but
of the fact that the levels of concern and the levels of exposure may
differ depending on the duration and route of exposure.
For non-threshold risks (generally, cancer risks), EPA uses the
slope of the dose-response curve for a pesticide in conjunction with an
estimation of human exposure to that pesticide to estimate the
probability of occurrence of additional adverse effects. Under FFDCA
section 408, for non-threshold cancer risks, EPA generally considers
cancer risk to be negligible if the probability of increased cancer
cases falls within the range of 1 in 1 million. EPA describes this
quantitative standard as a ``range'' because it does not want to impart
a false precision to numerical cancer risk estimates. EPA seeks to
identify risks differing significantly from a 1 in 1 million risk and
that involves both a quantitative as well as qualitative assessment of
what a risk estimate represents.
2. EPA policy on the children's safety factor. As the previous
brief summary of EPA's risk assessment practice indicates, the use of
safety factors plays a critical role in the process. This is true for
traditional 10X safety factors to account for potential differences
between animals and humans when relying on studies in animals (inter-
species safety factor) and potential differences among humans (intra-
species safety factor) as well as the FQPA's additional 10X children's
safety factor.
In applying the children's safety factor provision, EPA has
interpreted it as imposing a presumption in favor of applying an
additional 10X safety factor. (Ref. 8 at 4, 11). Thus, EPA generally
refers to the additional 10X factor as a presumptive or default 10X
factor. EPA has also made clear, however, that this presumption or
default in favor of the additional 10X is only a presumption. The
presumption can be overcome if reliable data demonstrate that a
different factor is safe for children. (Id.). In determining whether a
different factor is safe for children, EPA focuses on the three factors
listed in section 408(b)(2)(C)--the completeness of the toxicity
database, the completeness of the exposure database, and potential pre-
and post-natal toxicity. In examining these factors, EPA strives to
make sure that its choice of a safety factor, based on a weight-of-the-
evidence evaluation, does not understate the risk to children. (Id. at
24-25, 35).
C. SDWA and the Montreal Protocol/CAA
1. SDWA. SDWA (42 U.S.C. 300f et seq.) was enacted to assure that
water supply systems serving the public meet minimum national standards
for the protection of public health and to protect the underground
sources of drinking water upon which the public
[[Page 3428]]
relies. (See generally A Legislative History of the Safe Drinking Water
Act, Committee Print, 97th Cong., 2d Sess. (1982) at 533-541). Under
SDWA, EPA is authorized to set ``National primary drinking water
regulations'' (NPDWRs) governing contaminants which the Administrator
determines may have an adverse effect on the health of persons. NPDWRs
apply to ``public water systems'' nationwide and include monitoring and
reporting requirements. (42 U.S.C. 300g-1).
``Public water systems'' are defined as systems that provide water
to the public through pipes or other constructed conveyances for human
consumption and that have at least 15 service connections or regularly
serve at least 25 individuals. (42 U.S.C. 300f(4)(A)). By regulation,
EPA has interpreted ``regularly serve at least 25 individuals'' to mean
providing water to an average of at least 25 individuals daily at least
60 days of the year. (40 CFR 141.2). There are over 160,000 public
water systems in the United States. The vast majority of these systems
(95%) are small (i.e. serve populations of 3,300 persons or less) and
these systems only serve about 10% of the population. Many of these
small systems rely on groundwater as a water source. The largest 2% of
the public water systems serve 80% of the population and include the
large metropolitan water systems such as in New York City, Washington,
DC, Boston and Chicago. Most of these systems rely on surface waters as
their primary water source. Public drinking water systems provide water
to roughly 85 to 90% of the U.S. population.
In promulgating a NPDWR for a contaminant, EPA must establish both
a maximum contaminant level goal (MCLG) for that contaminant as well as
either a maximum contaminant level (MCL) or a treatment technology
requirement. (42 U.S.C. 300g-1(a)(3) and 300g-1(b)(4)(7)). MCLGs are
not regulatory requirements and do not impose any obligations on public
water systems. Rather, MCLGs are health goals that are to be set at a
level at which, in the Administrator's judgment, ``no known or
anticipated adverse effects on the health of persons occur and which
allows for an adequate margin of safety.'' (42 U.S.C. 300g-1(b)(4)(A)).
A MCL sets a level of the contaminant not to be exceeded by public
water systems and, with some exceptions is to be set as close to the
MCLG as is ``feasible.'' (42 U.S.C. 300g-1(b)(4)(B)). The Act defines
feasible to mean ``feasible with the use of the best technology,
treatment techniques or other means which the Administrator finds * * *
are available (taking costs into consideration).'' (42 U.S.C. 300g-
(b)(4)(D)). The legislative history for this provision makes it clear
that ``feasibility'' is to be defined relative to ``what may reasonably
be afforded by large metropolitan or regional public water systems.''
(A Legislative History of the Safe Drinking Water Act, Committee Print,
97th Cong., 2d Sess. (1982) at 550. MCLs appear at 40 CFR part 141,
subparts B and G).
A treatment technique requirement imposes an obligation on public
water systems to use an identified treatment technology and it must
``prevent known or anticipated adverse effects on the health of persons
to the extent feasible.'' (42 U.S.C. 300g-1(b)(7)(A). EPA may establish
treatment technique requirements in lieu of an MCL only if it is not
economically or technologically feasible to ascertain the level of the
contaminant. (Id.).
SDWA also authorizes EPA to set ``secondary'' drinking water
standards or ``SMCLs.'' Such standards specify levels which are
necessary to protect ``the public welfare,'' (42 U.S.C. 300f(2)), but
are not Federally enforceable (see A Legislative History of the Safe
Drinking Water Act, Committee Print, 97th Cong., 2d Sess. (1982) at
557). For example, such a contaminant level might be one which
adversely affects the odor or appearance of water so that a large
number of people discontinue using that source. SMCLs may vary by
geography or other circumstances. EPA has established SMCLs for 15
contaminants, which are intended to be guidelines for the States. (40
CFR part 143).
Every 6 years, EPA is required to review and revise ``as
appropriate'' its existing drinking water standards. (42 U.S.C. 300g-
1(b)(9)).
There is a long history of regulation of fluoride under SDWA. In
1975, EPA established a MCL for fluoride at a level varying between 1.4
milligrams (mg)/liter (L) and 2.4 mg/L depending on annual ambient air
temperature. (40 FR 59566, December 24, 1975). These levels were set to
prevent objectionable dental fluorosis. In 1981, South Carolina
petitioned EPA to revoke the fluoride MCL arguing that dental fluorosis
is merely a cosmetic effect not an adverse health effect. (See 50 FR
20164, May 14, 1985). In response to that petition, EPA took a series
of actions. First, in 1985, EPA established a MCLG for fluoride at 4
mg/L. (50 FR 47142, November 14, 1985) (At that time MCLGs were termed
``recommended maximum contaminant levels'' (RMCLs) under SDWA.). The
MCLG was set to protect against crippling skeletal fluorosis, an
adverse health effect associated with high levels of fluoride exposure.
EPA concluded that dental fluorosis, which had formed the basis for the
earlier MCL, was not an adverse health effect under SDWA but only a
cosmetic effect. Second, in 1986, EPA established a MCL for fluoride at
4 mg/L, again based on the crippling skeletal fluorosis endpoint. (51
FR 11396, April 2, 1986). Finally, also in 1986, EPA established a SMCL
for fluoride at 2 mg/L to protect against objectionable dental
fluorosis. (Id.). Judicial review of the MCLG was sought by both the
Natural Resources Defense Council (NRDC) and by South Carolina. (NRDC
v. EPA, 812 F.2d 721 (DC Cir. 1987)). NRDC argued that the level was
too high because, among other reasons, the MCLG should have been set on
dental fluorosis. Taking the opposite position, South Carolina claimed
that no MCLG at all was appropriate because the evidence did not
support that fluoride caused any adverse health effects. The DC Circuit
upheld EPA's regulation ruling that EPA had reasonably interpreted SDWA
term adverse health effect to be limited to functional impairments and
that EPA had reasonably concluded that effects of dental fluorosis were
cosmetic in nature and did not result in functional impairment. South
Carolina's challenge was dismissed based on the court's conclusion that
EPA had made a ``permissible administrative judgment'' based on the
evidence before it. (Id. at 725).
Subsequent to these rulemakings, EPA has on two occasions asked NAS
to reevaluate the potential risks of fluoride exposure in regard to the
MCLG/MCL. The NRC Report on the second request is discussed extensively
in Unit IV.D.
2. The Montreal Protocol/CAA and methyl bromide. The Montreal
Protocol is the international agreement aimed at reducing and
eliminating the production and consumption of stratospheric ozone-
depleting substances. The stratospheric ozone layer protects humans
from overexposure to harmful ultraviolet radiation. The United States
was one of the original signatories to the 1987 Montreal Protocol and
the United States ratified the Protocol in April, 1988. Congress then
enacted the Clean Air Act Amendments (CAAA) of 1990 which included
Title VI on Stratospheric Ozone Protection, codified as 42 U.S.C.
Chapter 85, Subchapter VI, to ensure that the United States could
satisfy its obligations under the Montreal Protocol. EPA issued
regulations in 40 CFR part 82 to implement this legislation and has
since modified and updated the regulations as needed. In 2009, the
Montreal Protocol became the first
[[Page 3429]]
universally ratified international environmental treaty.
Methyl bromide was added to the Montreal Protocol as an ozone-
depleting substance in 1992 through the Copenhagen Amendment to the
Protocol. The Parties to the Montreal Protocol (Parties) agreed that
each developed country's level of methyl bromide production and
consumption in 1991 should be the baseline for establishing a freeze.
Under the Montreal Protocol and Title VI of the CAAA the term
``consumption'' is a calculated amount equal to production plus imports
minus exports. EPA published a final rule in the Federal Register on
December 10, 1993 (58 FR 65018), listing methyl bromide as a Class I,
Group VI controlled substance, freezing U.S. production and consumption
at this 1991 baseline level of 25,528,270 kilograms, and setting forth
the percentage of baseline allowances for methyl bromide granted to
companies in each control period (each calendar year) until 2001, when
the complete phase-out would occur. This phase-out date was established
in response to a petition filed in 1991 under sections 602(c)(3) and
606(b) of CAAA of 1990, requesting that EPA list methyl bromide as a
Class I substance and phase out its production and consumption. This
date was consistent with section 602(d) of CAAA of 1990, which, for
newly listed Class I ozone-depleting substances, provides that ``no
extension [of the phase-out schedule in section 604] under this
subsection may extend the date for termination of production of any
class I substance to a date more than 7 years after January 1 of the
year after the year in which the substance is added to the list of
class I substances.''
At the Seventh Meeting of the Parties (MOP) in 1995, the Parties
made adjustments to the methyl bromide control measures and agreed to
reduction steps and a 2010 phase-out date for industrialized countries
with exemptions permitted for critical uses. At that time, the United
States continued to have a 2001 phase-out date in accordance with
section 602(d) of CAAA of 1990. At the Ninth MOP in 1997, the Parties
agreed to further adjustments to the phase-out schedule for methyl
bromide in industrialized countries, with reduction steps leading to a
2005 phase-out.
In October 1998, the U.S. Congress amended CAA to conform the U.S.
schedule to the schedule specified under the Protocol for developed
countries by requiring EPA to move the date for ending production to
January 1, 2005 and authorizing EPA to provide certain exemptions.
These amendments were contained in section 764 of the 1999 Omnibus
Consolidated and Emergency Supplemental Appropriations Act (Pub. L.
105-277, October 21, 1998) and were codified in section 604 of CAA. (42
U.S.C. 7671c). The amendment that specifically addresses the critical
use exemption (CUE) appears at section 604(d)(6), 42 U.S.C.
7671c(d)(6). EPA revised the phase-out schedule for methyl bromide
production and consumption in a direct final rulemaking on November 28,
2000 (65 FR 70795) (FRL-6906-4), which allowed for the phased reduction
in methyl bromide consumption specified under the Protocol and extended
the phase-out to 2005. EPA again amended the regulations to allow for
an exemption for quarantine and preshipment purposes with an interim
final rule on July 19, 2001 (66 FR 37752)(FRL-7014-5) and with a final
rule on January 2, 2003 (68 FR 238)(FRL-7434-1).
On December 23, 2004 (69 FR 76982)(FRL-7850-8), EPA published a
final rule that established the framework for the CUE; set forth a list
of approved critical uses for 2005; and specified the amount of methyl
bromide that could be supplied in 2005 from stocks and new production
or import to meet the needs of approved critical uses. EPA subsequently
published rules applying the CUE framework to the 2006, 2007, 2008,
2009, and 2010 control periods.
Since its introduction in 2004, sulfuryl fluoride has served as an
alternative to methyl bromide with regard to methyl bromide's use as a
post-harvest commodity fumigant and fumigant for food processing
warehouses and facilities. Introduction of sulfuryl fluoride has played
a significant role in the United States' reduction of the postharvest
methyl bromide CUEs by almost 80% over the last 6 years.
IV. Regulatory History of Sulfuryl Fluoride
A. In General
Sulfuryl fluoride is a fumigant that is used to kill insect pests,
rodents, birds, and snakes. It is used both for the treatment of
structures as well as stored food. Sulfuryl fluoride was initially
registered under FIFRA as Vikane[supreg], a fumigant to treat drywood
termites and other wood boring insects in 1959. More recently, sulfuryl
fluoride was identified as a potential alternative for uses of methyl
bromide as a food fumigant and as a fumigant of food processing
facilities. It was registered under the name of ProFume[supreg] by Dow
AgroSciences for these uses in 2004 and 2005. Sulfuryl fluoride has
achieved significant penetration of several methyl bromide markets. EPA
and Dow AgroSciences have concluded that sulfuryl fluoride is used in
approximately 40% of mills and food processing facilities and is used
on 100% of cocoa beans. More recently, sulfuryl fluoride has been used
extensively in fumigating walnuts and dried fruit other than raisins.
Sulfuryl fluoride rapidly breaks down to form sulfate and the
fluoride anion.
B. 2004 Registration and Tolerances
In 2004, EPA registered sulfuryl fluoride for use as a direct
fumigant of various grains and dried fruits under FIFRA and established
corresponding tolerances under FFDCA section 408. (69 FR 3240, January
23, 2004)(FRL-7342-1). Tolerances were established for both the parent
chemical, sulfuryl fluoride, and the breakdown product, fluoride. (For
convenience, both the sulfuryl fluoride and fluoride tolerances
established in association with the use of sulfuryl fluoride are,
hereinafter, referred to in this document as sulfuryl fluoride
tolerances.) Separate risk assessments were conducted for sulfuryl
fluoride and fluoride.
In assessing the risk of fluoride, EPA relied on the MCLG that had
been established under SDWA to establish a RfD-like value for fluoride.
Established in 1986, the fluoride MCLG is 4 mg/L and is based on the
adverse effect of crippling skeletal fluorosis. (40 CFR 141.41). As was
the case with the MCLG, EPA determined that dental fluorosis was not an
adverse effect and thus was not an appropriate benchmark for evaluating
the safety of fluoride under FFDCA. EPA also determined that, ``given
the wealth of reliable human data on fluoride,'' the presumptive
additional 10X children's safety factor could be removed. (69 FR 3253)
(FRL-7342-1). Using the MCLG in combination with high-end water
consumption information and body weights for age subgroups from infants
through adults, EPA calculated safe fluoride levels on a milligram of
fluoride per kilogram of body weight per day (mg/kg/day) basis. (69 FR
3248) (FRL-7342-1). These RfD-like values were compared to estimated
aggregate exposure levels to fluoride from numerous sources: From use
of the pesticides sulfuryl fluoride and cryolite on food; from natural
and artificial levels of fluoride in drinking water; from background
levels of fluoride in beverages, food, and ambient air; and from
fluoride in dental products. Because aggregate exposure for each of
[[Page 3430]]
the age-based population subgroups fell below the calculated RfD-like
values, EPA concluded that the tolerances were safe.
Although FAN did not submit comments on the notice announcing Dow
AgroSciences' petition for tolerances, FAN had submitted objections to
an earlier sulfuryl fluoride tolerance action. That earlier tolerance
action was the establishment of temporary tolerances for sulfuryl
fluoride on various grains and dried fruits in conjunction with an
experimental use permit for sulfuryl fluoride under FIFRA section 5. (7
U.S.C. 136c). Sulfuryl fluoride was never used under that experimental
permit and the temporary tolerances were revoked with the establishment
of the 2004 tolerances. However, EPA treated the FAN objections as
comments on the petition for tolerances and responded to them in detail
in promulgating the 2004 tolerances. (Refs. 13, 14 and 15). Because EPA
recognized that the NAS was undertaking a comprehensive evaluation of
the latest data on fluoride, EPA noted that its review of the data
submitted by FAN was preliminary and subject to reevaluation once the
NRC Report was complete. (Ref. 14).
On March 23, 2004, FAN, joined by Beyond Pesticides, filed
objections to the 2004 tolerances and requested a hearing on those
objections. (See Unit IV.D.).
C. 2005 Registration and Tolerances
In 2005, EPA registered sulfuryl fluoride for use as a direct
fumigant on additional commodities and also as a structural fumigant
for food processing facilities under FIFRA and established
corresponding tolerances under FFDCA section 408. (70 FR 40899, July
15, 2005) (FRL-7723-7). Again, EPA relied on the MCLG in assessing the
aggregate risk to fluoride, taking into account the additional fluoride
exposure from the new uses. (Id. at 40905). EPA also assessed fluoride
risk using the Point of Departure suggested by NAS' Institute of
Medicine for evaluating the risk of crippling skeletal fluorosis. (Id.
at 40906). Under both approaches, EPA concluded that the tolerances
were safe.
FAN submitted comments on the notice announcing Dow AgroSciences'
petition for tolerances. EPA prepared a detailed response to these
comments. (Ref. 16).
On September 13, 2005, FAN, joined by Beyond Pesticides and the
Environmental Working Group, filed objections to the 2005 tolerances
and requested a hearing on those objections. (See Unit IV.D.).
D. The 2006 NRC Report
In 2003, EPA's Office of Water (OW) asked the NRC to review new
research on fluoride to determine whether the MCLG and SMCL for
fluoride established under SDWA adequately protect the public health.
(Ref. 17 at xii). Specifically, EPA asked NRC ``to review toxicologic,
epidemiologic, and clinical data on fluoride--particularly data
published since NRC's previous (1993) report--and exposure data on
orally ingested fluoride from drinking water and other sources * * *,
'' and ``to evaluate independently the scientific basis of EPA's MCLG
of 4 mg/L and SMCL of 2 mg/L in drinking water and the adequacy of
those guidelines to protect children and others from adverse health
effects.'' (Id. at 2). NRC was also asked to identify data gaps and to
make recommendations for future research relevant to setting the MCLG
and SMCL for fluoride.'' (Id.).
NRC completed its report in March 2006. Its overall conclusions
were that: (1) ``EPA's MCLG of 4 mg/L should be lowered;'' (2) further
study was needed to assess the protectiveness of the SMCL of 2 mg/L;
and (3) ``EPA should update the risk assessment of fluoride to include
new data on health risks and better estimates of total exposure
(relative source contribution) in individuals and to use current
approaches to quantifying risk, considering susceptible subpopulations,
and characterizing uncertainties and variability.'' (Id. at 352).
NRC's decision as to the MCLG was driven by its concern regarding
the fluoride exposure levels that produce the following effects: Severe
enamel fluorosis (referred to in this document generally as severe
dental fluorosis); clinical stage II skeletal fluorosis; and bone
fractures. (Id.). Previously, all forms of dental fluorosis had been
regarded merely as cosmetic effects and thus not properly considered in
setting a MCLG. In the 2006 Report, NRC stated that: ``The damage to
teeth caused by severe enamel fluorosis is a toxic effect that the
majority of the committee judged to be consistent with prevailing risk
assessment definitions of adverse health effects.'' (Id. at 127). NRC
reasoned as follows:
Severe enamel fluorosis is characterized by enamel loss and
pitting. This damage compromises enamel's protective barrier and can
make the teeth more susceptible to environmental stresses and to
caries formation because it allows bacteria, plaque, and food
particles to become entrapped in the enamel. Caries is dental decay
caused by bacterial infection. When the infection goes unchecked,
cavities may form that can cause toothache and tooth sensitivity to
temperature and sweets. If cavities are untreated, the infection can
lead to abscess, destruction of bone, and spread of the infection to
other parts of the body. While increased risk of caries has not been
firmly established, the majority of the committee found that
destruction of the enamel and the clinical practice of treating the
condition even in the absence of caries provide additional lines of
evidence for concluding that severe enamel fluorosis is an adverse
health effect.
(Id. at 346) (citation omitted).
Two of the 12 members of the NRC committee ``did not agree that
severe enamel fluorosis should now be considered an adverse health
effect'' and would have characterized it as an ``adverse dental
effect.'' (Id.). Nonetheless, these two committee members concurred in
the overall NRC conclusion that the MCLG should protect against this
effect. Specifically, the Report stated: ``Despite their disagreement
on characterization of the condition, these two members concurred with
the committee's conclusion that the MCLG should prevent the occurrence
of this unwanted condition.'' (Id.). Turning to the level of exposure
that can cause severe dental fluorosis, NRC concluded that such
fluorosis occurs at an ``appreciable frequency'' in communities with
water supplies containing at or near 4 mg/L but that ``the prevalence
of severe enamel fluorosis would be reduced to nearly zero by bringing
the water fluoride levels in these communities down to below 2 mg/L.''
(Id. at 127-128).
As to skeletal fluorosis, NRC concluded that the MCLG should not be
based solely on stage III (crippling) skeletal fluorosis but also take
into account stage II skeletal fluorosis (the stage before mobility is
significantly affected). Although the data on what level of fluoride
exposure was need to cause stage II skeletal fluorosis was
inconclusive, NRC ventured that the data ``suggest[] that the MCLG
might not protect all individuals from the adverse stages of the
condition.'' (Id. at 347). NRC advised that ``more research is needed
to clarify the relationship between fluoride ingestion, fluoride
concentrations in bone, and stage of skeletal fluorosis.'' (Id.).
NRC found the evidence on the level of fluoride exposure which
could lead to an increased risk of bone fracture to be somewhat more
compelling. There was general agreement by NRC with the proposition
``that there is scientific evidence that under certain conditions
fluoride can weaken bone and increase the risk of fractures.'' (Id. at
348). Further, ``the majority of the committee
[[Page 3431]]
concluded that lifetime exposure to fluoride at drinking water
concentrations of 4 mg/L or higher is likely to increase fracture rates
in the population, compared with exposure to 1 mg/L, particularly in
some demographic subgroups that are prone to accumulate fluoride into
their bones (e.g., people with renal disease).'' (Id.). Three members
of the NRC committee reached a more tempered conclusion suggesting that
``the evidence only supported a conclusion that the MCLG might not be
protective against bone fracture.'' (Id.) (emphasis in original).
Turning to the SMCL, NRC noted that, even if this standard now only
addresses, at worst, moderate dental fluorosis, the 2 mg/L ``SMCL does
not completely prevent the occurrence of moderate enamel fluorosis.''
(Id. at 352). Specifically, NRC found that ``[p]ast evidence indicated
an incidence range of 4% to 15% (50 FR 20164 [1985]).'' (Ref. 17 at
130). NRC indicated that ``[t]he prevalence of moderate cases that
would be classified as being of aesthetic concern (discoloration of the
front teeth) is not known but would be lower than 15%.'' (Id.). In the
end, NRC recommended further study of U.S. communities with drinking
water fluoride levels of greater than 1 mg/L to better characterize the
degree and consequences of moderate dental fluorosis and the levels at
which these effects occur. (Id. at 352-353).
NRC also examined in detail whether fluoride caused reproductive,
developmental, neurotoxic, neurobehavioral, or cancer effects or had
adverse effects on the endocrine, gastrointestinal, renal, hepatic, and
immune systems. Although NRC recommended further study with regard to
many of these effects, it did not conclude that any of these potential
effects warranted a lowering of the MCLG.
A substantial portion of the NRC Report is devoted to examining
fluoride exposure in the United States. NRC considered exposures from
drinking water; background levels in food, beverages, soil, and air;
residues in food from pesticide usage; and dental products. Drinking
water was generally the most significant source but certain age groups'
exposures from background levels in food and water and from dental
products were not insubstantial. (Id. at 60, Fig.2-1). NRC summarized
the information on fluoride levels in water from public systems as
follows:
Of the 144 million people with fluoridated public water supplies
in 1992, approximately 10 million (7%) received naturally
fluoridated water, the rest had artificially fluoridated water. Of
the population with artificially fluoridated water in 1992, more
than two-thirds had a water fluoride concentration of 1.0 mg/L, with
almost one-quarter having lower concentrations and about 5% having
concentrations up to 1.2 mg/L.
Of the approximately 10 million people with naturally
fluoridated public water supplies in 1992, approximately 67% had
fluoride concentrations <= 1.2 mg/L. Approximately 14% had fluoride
concentrations between 1.3 and 1.9 mg/L and another 14% had between
2.0 and 3.9 mg/L; 2% (just over 200,000 persons) had natural
fluoride concentrations equal to or exceeding 4.0 mg/L.
(Id. at 25) (citations omitted).
As to persons who rely on private water sources, NRC noted:
Little information is available on the fluoride content of
private water sources, but the variability can reasonably be
expected to be high and to depend on the region of the country.
Fluoride measured in well water in one study in Iowa ranged from
0.06 to 7.22 mg/L (mean, 0.45 mg/L); home-filtered well water
contained 0.02-1.00 mg/L (mean, 0.32 mg/L). Hudak (1999) determined
median fluoride concentrations for 237 of 254 Texas counties (values
were not determined for counties with fewer than five observations).
Of the 237 counties, 84 have median groundwater fluoride
concentrations exceeding 1 mg/L; of these, 25 counties exceed 2 mg/L
and five exceed 4 mg/L. Residents in these areas (or similar areas
in other States) who use groundwater from private wells are likely
to exceed current guidelines for fluoride intake.
(Id. at 25-26).
E. The Objectors' Objections and Hearing Requests
1. Procedural history. The Objectors have filed several sets of
objections and hearing requests on the 2004 and 2005 tolerance actions
as a result of various preliminary responses by EPA to FAN's requests
for hearing. As noted, the Objectors filed objections and hearing
requests on March 23, 2004, as to the 2004 tolerance action. On June 4,
2005, EPA responded by letter to the Objectors' hearing request noting
numerous potential flaws in the request and giving the Objectors 90
days to respond to the issues raised. On July 15, 2005, EPA issued
additional tolerances for sulfuryl fluoride/fluoride and on September
13, 2005, the Objectors submitted objections and hearing requests as to
these tolerances. Then, on December 16, 2005, Objectors submitted a
revised set of objections and hearing requests in response to EPA's
earlier letter. EPA responded to the December 16, 2005 filing on
February 13, 2006, seeking further clarification on several issues and
giving the Objectors 90 days to respond. On November 6, 2006, the
Objectors filed a second set of revised objections and hearing requests
that consolidated their objections to both the 2004 and 2005 tolerance
actions. (Ref. 3).
The Objectors have made two additional filings with EPA. First, on
June 1, 2006, the Objectors filed with EPA a motion for a stay of 2004
and 2005 tolerance actions. (Ref. 2). This stay request was largely in
response to the NRC Report on fluoride. Second, in February 2009, the
Objectors filed a collection of 18 studies addressing potential effects
of fluoride exposure on IQ levels in children. (Ref. 18).
2. Consolidated objections and hearing requests. The Objectors'
consolidated objections and hearing requests filed in November, 2006,
raise six main arguments:
The fluoride MCLG is not protective of the effects of
fluoride on teeth and bones;
The fluoride MCLG is not protective of other neurotoxic,
endocrine, and renal effects of fluoride;
EPA has not adequately protected children;
EPA cannot determine the safety of sulfuryl fluoride and
fluoride in the absence of a developmental neurotoxicity study;
EPA has underestimated exposure to fluoride; and
EPA has committed procedural errors in violation of the
Administrative Procedures Act (APA) (5 U.S.C. 551 et seq.).
The Objectors argue that the 4 mg/L MCLG for fluoride does not
provide adequate protection against severe dental fluorosis, pre-
crippling skeletal fluorosis, and increased risk of bone fractures. The
Objectors cite to government and literature studies documenting the
significant consequences from severe dental fluorosis: ``The enamel of
the teeth become so porous that the teeth are `prone to fracture and
wear' (ATSDR 2003), `subject to extensive mechanical breakdown of the
surface' (Aoba & Fejerskov 2002), with a `friable enamel that can
result in loss of dental function' (Burt & Eklund 1999).'' (Ref. 3 at
16). On pre-crippling skeletal fluorosis, the Objectors assert that
pre-crippling skeletal fluorosis can be a painful condition for some
people. (Id. at 19). Finally, the Objectors cite to many studies on the
risk of increased bone fractures from fluoride exposure that allegedly
show that these increased risks occur at fluoride exposure levels lower
than those in communities with drinking water levels of 4 mg/L. (Id. at
22-24).
The Objectors also argue that the 4 mg/L MCLG for fluoride does not
[[Page 3432]]
protect against fluoride's effects on the brain, the endocrine system,
and the kidneys. The Objectors cited a study in rats allegedly showing
brain damage at a fluoride exposure level in water of 1 ppm [1 mg/L]
and epidemiological studies showing reductions in IQ levels in children
at a fluoride exposure level of 0.9 ppm [0.9 mg/L] in iodine-deficient
areas and 1.8 ppm [1.8 mg/L] in areas with sufficient iodine in the
diet. (Id. at 25-26). As to the endocrine system, the Objectors
reference the NRC Report's conclusion that fluoride is an ``endocrine
disruptor'' and argue that fluoride can have adverse effects on insulin
secretion and on the thyroid. (Id. at 31-35). The Objectors argue that
fluoride can affect insulin secretion where drinking water contains 4
mg/L or less of fluoride, (Id. at 33), and that NRC has concluded that
thyroid effects can occur at exposure levels as low as 0.01-0.03 mg/kg/
day for iodine-deficient humans, (Id. at 35). As to the kidneys, the
Objectors claim that data show that adverse effects can occur when
exposure levels in water are at the 1 and 2 mg/L level. (Id. at 38-39).
With regard to the safety of children, the Objectors assert that
EPA, without basis or explanation, has applied a significantly less
protective RfD to infants and children than the RfD applicable to
adults. The Objectors note that prior to the promulgation of the 2004
fluoride tolerances EPA had utilized a RfD of 0.114 mg/kg/day for all
population age groups. (Id. at 59). The Objectors point out, however,
that, in both the 2004 and 2005 tolerance actions, EPA increased the
RfD for several of the infant and children age groups to levels that
are allegedly as much as 10 times higher than the RfD for adults. This
higher RfD for infants and children, the Objectors argue, is
inconsistent with the statutory requirement for providing an additional
margin of safety for infants and children, the basic toxicological
principle that bodyweight affects the impact of a chemical, data
showing adverse effects at levels below the RfD levels, and data
showing that children's bones are more sensitive to fluoride than
adult's bones. (Id. at 58-67). Further, the Objectors assert that EPA
failed to take into account, in its decision on the safety of fluoride
to infants and children, the uncertainty in the database concerning
fluoride's neurotoxic effects, and fluoride's effects on the endocrine
system. (Id. at 68-70).
A developmental neurotoxicity study on sulfuryl fluoride, the
Objectors claim, is critical to understanding the potential harmful
effects of sulfuryl fluoride and fluoride. They argue that EPA's
reasons for waiving the study lack merit and that a developmental
neurotoxicity study is mandated given NRC's conclusion that fluoride is
neurotoxic and that effects on the brain, including rare and severe
effects, were seen in animal studies with sulfuryl fluoride. (Id. at
72-79).
Turning to human exposure to fluoride, the Objectors argue that EPA
has underestimated fluoride exposure and corrected fluoride values show
that some people are exposed to unsafe levels of fluoride. The
Objectors claim EPA made numerous errors in estimating fluoride
exposure: (1) EPA underestimated average fluoride levels in water, (Id.
at 81-82); (2) EPA considered only average water and food consumption
levels instead of taking into account the full range of consumption
amounts, (Id. at 82-84, 105-106); (3) EPA underestimated fluoride
exposures from toothpaste, (Id. at 88-91); and (4) EPA had insufficient
data to estimate residues of fluoride on food from fumigation with
sulfuryl fluoride (Id. at 106). The Objectors contend that a risk
assessment using corrected exposure values will show that hundreds of
thousands of people exceed the 0.114 mg/kg/day RfD and that millions of
people would exceed a RfD set based on an endpoint of severe dental
fluorosis. (Id. at 86, 94-95).
Finally, the Objectors claim that EPA has made several procedural
errors that violate the dictates of the APA. First, the Objectors argue
that EPA has unreasonably delayed responding to their objections and
hearing requests filed in March 2004. Second, the Objectors argue that
EPA erred by not making its risk assessment available at the time of
issuance of the 2005 tolerance action. Third, EPA's failure to place
all requested documents in the record, according to the Objectors, has
thwarted full public participation. Fourth, the Objectors assert it was
a procedural error for EPA to issue sulfuryl fluoride tolerances
without first obtaining the advice of NRC.
The Objectors have also sought an adjudicatory hearing on each of
these objections. In support of their hearing request, the Objectors
have submitted all the data referenced in their consolidated
objections.
F. The Objectors' Stay Request
On June 1, 2006, the Objectors filed a motion with EPA seeking a
stay of the effectiveness of the 2004 and 2005 final rules establishing
sulfuryl fluoride tolerances. A stay of the effectiveness of these
rules would essentially ban use of sulfuryl fluoride because if the
tolerances are not effective then any sulfuryl fluoride or fluoride
residue remaining in treated foods would render the food adulterated
under FFDCA and subject to seizure. This stay request appears to have
been triggered by the March 2006 release of the NRC Report on fluoride.
(Ref. 2 at 4). The Objectors argued they were entitled to a stay
because they had demonstrated (1) that they were likely to prevail on
the merits of their objections; (2) the tolerances posed an imminent,
substantial and irreparable harm; (3) no other parties would be
substantially harmed by a stay; and (4) the public interest supported a
stay. (Id. at 2). EPA held a 30-day comment period on the stay request.
(71 FR 38125, July 5, 2006) (FRL-8075-6).
To support their likelihood of success on the merits argument, the
Objectors make similar arguments to those contained in their
consolidated objections. As to irreparable harm, the Objectors cite to
the NRC Report claiming it linked fluoride not just to adverse effects
on bones and teeth but also to interactive and synergistic toxic
effects with other chemicals, cancer, and diabetes, as well as adverse
effects on the brain, thyroid, pineal gland, kidney, liver, and the
endocrine, immune, gastrointestinal, and reproduction systems. (Ref. 2
at 11, 13-15). Further, the Objectors cite to the ``high levels of
fluoride from pesticides'' arguing that ``[a]s a result of these broad-
reaching, staggeringly high fluoride tolerances, EPA's own data show
that sulfuryl fluoride will become the second largest daily source of
fluoride in the US.'' (Id. at 3, 35). The Objectors assert that other
parties, including Dow AgroSciences, will not be substantially harmed
``in view of the overwhelming concern for public health at the heart of
the statute.'' (Id. at 36). Finally, the Objectors argue the public
interest favors a stay because a stay would protect the public health.
(Id. at 37).
G. Comments of Dow AgroSciences
Dow AgroSciences has filed two sets of comments on these matters.
First, Dow AgroSciences filed comments on the Objectors' request for a
stay of the effectiveness of the sulfuryl fluoride tolerances during
the public comment period during mid-2006. (Ref. 19). Second, in
October 2006, Dow AgroSciences submitted a memorandum to EPA arguing
that the Objectors' were not entitled to a hearing on their objections.
(Ref. 20).
1. Comments on stay request. In its comments, Dow AgroSciences
offered a series of reasons as to why a stay was not warranted. First,
Dow AgroSciences argues that EPA should follow the
[[Page 3433]]
already-established process for how the sulfuryl fluoride/fluoride
tolerances would be reviewed in light of the NRC Report. This process,
according to Dow AgroSciences, involves an analysis of the NRC Report
by EPA's OW followed by a re-evaluation of the tolerances by EPA's OPP.
(Ref. 19 at 6-7). Dow AgroSciences asserts that ``[a]bandoning now a
process established by the Agency and relied upon by SF registrants and
the scientific community would be arbitrary, unfair and unwarranted.''
(Id. at 7).
Second, Dow AgroSciences argues that the stay request is delinquent
because it was not filed within 60 days of issuance of the final
tolerance actions. (Id. at 8). Dow AgroSciences bases this claim on the
statutory requirement that objections to a tolerance must be filed
within 60 days of issuance.
Third, Dow AgroSciences claims that a stay of the tolerance action
is inappropriate because the stay request does not address ``the
underlying ProFume registration under FIFRA * * *.'' (Id. at 10).
According to Dow AgroSciences, ``[b]ypassing the hearing rights and
other procedural requirements provided by FIFRA would deny Dow
AgroSciences and other adversely affected parties their due process
rights under the U.S. Constitution.'' (Id. at 9).
Fourth, Dow AgroSciences argues that the NRC Report only indicates
a concern for ``that small, localized segment of the population exposed
to high natural fluoride levels.'' (Id. at 12). Such ``an exceedingly
small, isolated number of individuals,'' Dow AgroSciences contends,
would not constitute a ``major identifiable'' subgroup which is the
regulatory focus under FFDCA section 408. (Id.).
Fifth, Dow AgroSciences challenged the Objectors' claims that the
NRC Report showed that there is a safety concern with fluoride. Dow
AgroSciences noted that as to many potential health effects the NAS had
either concluded that no risks were present from exposure in drinking
water at 4 mg/L or there was insufficient data showing effects and more
study was necessary. (Id. at 14). With regard to fluoride's effects on
the risk of bone fractures, Dow AgroSciences argues that EPA had
previously dismissed the value of two studies on which NRC relied and
implies that NRC did not give proper weight to a recent study from the
University of Michigan. (Id. at 15-16). Further, Dow AgroSciences
claims that NRC actually had little concern for a potential link
between fluoride and stage II skeletal fluorosis. According to Dow
AgroSciences, NRC emphasized insufficiency of data on this effect and
merely called for more research. (Id. at 18). Finally, Dow AgroSciences
contends that NRC stepped beyond its competence in offering advice on
the legal conclusion of whether severe dental fluorosis is an adverse
health effect. (Id. at 19). Dow AgroSciences notes that a prior NRC
panel had declined to make this ultimate conclusion and that a prior
court ruling had indicated this was a question of statutory
interpretation under SDWA. (Id. at 19-20). Switching tacks, Dow
AgroSciences then argues there is a dispute within the scientific
community as to whether severe dental fluorosis is an adverse effect.
(Id. at 20).
Sixth, Dow AgroSciences argues that EPA is not authorized to
consider exposure to fluoride from artificial fluoridation of public
water supplies in evaluating the safety of the sulfuryl fluoride/
fluoride tolerances. (Id. at 21). Although acknowledging that FFDCA
section 408 directs EPA to consider ``aggregate exposure'' to both
pesticides and other related substances, Dow AgroSciences contends that
``[i]t is unnecessarily strained and counterintuitive to set tolerances
for pesticides in or on food by looking at the therapeutic use of
chemically related substances in humans.'' (Id.). As support for this
proposition, Dow AgroSciences asserts that the definition of
``pesticide chemical residue'' limits EPA to considering pesticide
chemicals and their degradates and metabolites. Further, Dow
AgroSciences claims that the most plausible reading of the term ``other
related substances'' is that this term covers other related
``pesticidal'' substances. (Id.at 22).
Finally, Dow AgroSciences claims that EPA overestimated exposure to
fluoride from use of sulfuryl fluoride. Specifically, Dow AgroSciences
states that its records show that sulfuryl fluoride has been utilized
less extensively than EPA projected and at lower rates than EPA
expected. (Id. at 34-35). When more realistic values are used in the
exposure assessment, Dow AgroSciences contends that fluoride exposure
from use of sulfuryl fluoride declines by over 80%. (Id. at 35).
2. Comments on the hearing requests. In a memorandum submitted to
EPA in October 2006, Dow AgroSciences offered several reasons as to why
the Objectors were not entitled to a hearing on their claims. First,
Dow AgroSciences argues that many of the issues raised by the Objectors
fail to state a material issue of fact because they are contingent in
nature or otherwise fail to raise a disputed matter. (Ref. 20 at 9).
Second, Dow AgroSciences claims that a number of the Objectors' issues
dispute science policy determinations by EPA and thus do not constitute
a matter of fact to be resolved at a hearing. (Id. at 11). For example,
Dow AgroSciences identifies EPA conclusions regarding issues such as
what constitutes a ``conservative assumption,'' a ``significant
subpopulation,'' or an ``adverse health effect'' as decisions based on
policy, as opposed to factual, reasons. Third, Dow AgroSciences asserts
that the Objectors' claim of procedural errors by EPA is a legal issue
not appropriate for a hearing. Fourth, Dow AgroSciences argues that
many of the Objectors' claims are ``no more than mere disagreements
with Agency determinations made in earlier stages of the rulemaking
process.'' (Id. at 12-13). According to Dow AgroSciences:
In many instances, Objectors support their issues by citing to
studies that have already been reviewed by EPA and have, either
expressly or effectively, been found scientifically inadequate,
procedurally flawed, or lacking in the requisite amount of empirical
support. Objectors cite to these studies in spite of the clear edict
that ``[m]ere differences in the weight or credence given to
particular scientific studies * * * are insufficient'' to prompt EPA
to hold a hearing. [citation omitted]. Clearly, Objectors disagree
with EPA's interpretations of these studies, but such disagreement
is irrelevant in the Agency's decision to grant a hearing on the
objections submitted.
(Id. at 13).
Fifth, Dow AgroSciences contends that the Objectors have not
submitted sufficient evidence in support of their claims based on Dow
AgroSciences' conclusion that the NRC Report, upon which the Objectors
rely, does not in fact substantiate the Objectors' position. (Id.)
Finally, even where the NRC Report does support the Objectors' claims,
Dow AgroSciences asserts that a hearing is not appropriate because the
NRC Report was performed under the aegis of SDWA to review the fluoride
MCLG and SMCL and not the sulfuryl fluoride/fluoride tolerances and
because the NRC Report did not generate new data but simply reviewed
studies already examined by EPA. (Id. at 17-18). Dow AgroSciences
concludes that the ``NRC's differences in opinion on the three issues
detailed below [bone fracture, skeletal fluorosis, severe dental
fluorosis] are just that--mere differences of opinion--and should be
evaluated as such.'' (Id. at 18).
V. EPA's Proposed Response to the Objections
EPA is proposing to grant the objections to the establishment of
the
[[Page 3434]]
sulfuryl fluoride/fluoride tolerances based on EPA's agreement with the
Objectors that (1) fluoride risks should be assessed based upon a more
sensitive endpoint than crippling skeletal fluorosis; and (2) assessing
fluoride risks on a more sensitive endpoint shows that aggregate
exposure to fluoride for major identifiable subgroups does not meet the
safety standard in FFDCA section 408. In reaching this conclusion, EPA
has taken into account, in addition to the arguments and data submitted
by the Objectors, the 2006 NRC Report on fluoride, the detailed
analysis of that Report and followup peer-reviewed assessment of
fluoride by EPA's OW, and a revised risk assessment of fluoride
performed by EPA's OPP in light of the NRC Report, and usage
information submitted by Dow AgroSciences. (All of these materials have
been included in the docket for this action.). The conclusions of the
NRC Report are described in Unit IV.D. In Units V.A. and V.B., EPA
summarizes OW's reassessment of fluoride risk undertaken on the
recommendation of NRC, OPP's revised fluoride risk assessment, and sets
forth EPA's proposed findings on the safety of the sulfuryl fluoride
tolerances. Unit V.C. addresses comments from Dow AgroSciences
pertaining to the safety of fluoride, and in particular, the
conclusions of the NRC Report on fluoride safety. EPA is inviting
public comment on all aspects of this proposal, including the
underlying scientific documents discussed in Units V.A and V.B.
A. OW's Reassessment of Fluoride Risk
One of the principal conclusions of the NRC Report was that EPA
``should update the risk assessment of fluoride to include new data on
health risks and better estimates of total exposure (relative source
contribution) in individuals and to use current approaches to
quantifying risk, considering susceptible subpopulations, and
characterizing uncertainties and variability.'' (Ref. 17 at 352). As
the NRC Report was prepared in the context of evaluating the fluoride
MCLG and SMCL for drinking water, EPA's OW took the lead in preparing
this revised fluoride risk assessment. OW's risk assessment was broken
into two parts: (1) A dose-response analysis directed at establishing a
RfD for fluoride; and (2) an exposure and relative source contribution
analysis that catalogued and estimated the various sources of fluoride
exposure and characterized the risk of that exposure. EPA's OPP
contributed information on exposure to fluoride from use of the
pesticides sulfuryl fluoride and cryolite (which also breaks down to
fluoride). Both parts of the OW risk assessment were subjected to an
external peer review by scientific experts.
1. Dose-response analysis. OW's dose-response analysis focused on
``examining available dose-response data for the critical noncancer
effects of fluoride on teeth and bone identified by NRC (2006) as
adverse health effects.'' (Ref. 21 at 1). For the most part, OW relied
on the extensive database of epidemiological studies evaluating the
relationship between the level of fluoride in drinking water and severe
dental fluorosis, dental caries, and stage II skeletal fluorosis. OW
noted a preference for older studies because determination of fluoride
exposure levels in more recent studies is made more difficult by ``the
widespread use of fluoride-containing dentifrices and mouth rinses, the
use of fluoride supplements in early childhood, and the potential
presence of fluoride in processed foods and beverages (a result of the
use of fluoridated water in the preparation of these products).'' (Id.
at 9).
a. Dental fluorosis. OW reviewed dozens of epidemiological studies
bearing on the relationship of fluoride exposure to severe dental
fluorosis. OW concluded that these studies supported the NRC Report
conclusion that ``the weight of evidence indicates that the threshold
for severe dental fluorosis occurs at a water fluoride level of about 2
mg/L.'' (Id. at 35). OW also concluded that one study in particular,
Dean (1942), provided the best data set for conducting a dose-response
analysis. (Id.). In reaching this conclusion, OW undertook a detailed
examination of the strengths and weaknesses of the study. OW summarized
the strengths as follows:
[The study was selected] due to its large size and geographic
scale (22 U.S. communities in 10 States; 5824 children), range of
fluoride concentrations evaluated (from 0.0 to 14.1 mg/L), and
selection of an appropriate age class (school children primarily
between the ages of 9 and 14; an age class in which a very high
percentage of permanent teeth have erupted). In addition, every
tooth per subject was examined using the same scoring protocol, and
the community water supplies were tested for fluoride content by the
same chemist. This dataset is sufficiently large and robust to
support statistical analysis, the protocol is sound, and there were
few alternate sources of commercially available fluoride (e.g.,
mouthwash, detrifrice, etc.) or fluoridated community water supplies
to confound the dental fluorosis data collected by Dean (1942) at
the time this study was conducted (late 1930's and early 1940's).
(Id. at 92) (citations and internal cross-references omitted). Study
weaknesses, identified by OW, included the lack of data on water intake
amounts and fluoride exposure from food and the fact that the
analytical method used for measuring fluoride was not as sensitive to
fluoride and free from sensitivity to interfering substances as current
fluoride methods. (Id. at 12-13). Additionally, although the time
period of the study (late 1930's through early 1940's) makes assessing
fluoride exposure levels relatively easier than it is today, the time
period also raises uncertainties due to differences between the late
1930's/early 1940's and today with regard to ``dental hygiene, dietary
intakes, body weights and puberty/hormonal condition (e.g., age of
menarche).'' (Id. at 13). OW concluded that the lack of information
relating to exposure from food and water could be overcome, to a large
extent, by other data. (Id. at 103-105; Appendix C). As to the
analytical method, OW found that it was ``sensitive to small increments
of fluoride over a range of 0.0 ppm to 3.0 ppm, the critical range for
assessing the threshold for severe [dental] fluorosis. * * * '' (Id. at
13). A full discussion of the study can be found in the OW's dose-
response report. (Id. at 10-13, 87-94, 103-107).
OW also reviewed a smaller set of studies examining the
relationship between dental fluorosis and dental caries and the
relationship between fluoride levels in drinking water and dental
caries. These data were examined to assess whether ``[t]he relationship
between caries and fluoride exposure displays the U-shaped dose-
response that characterizes many nutrients where there are adverse
effects with intakes that are below those that confer a benefit and
adverse effects with intakes that are greater than those with
benefit.'' (Id. at 37). After closely examining all of the data, OW
concluded:
Although the data are supportive of NRC (2006) conclusions
regarding enamel pitting they are moderately rather than strongly
consistent with the hypothesis that the pitting of the enamel leads
to an increased risk for caries. Socioeconomic status, availability
of dental care, and personal dental hygiene habits are likely to
confound the results from individual studies of the caries
relationship. For this reason, OW has selected the pitting of the
dental enamel as the critical effect for the dose-response analysis.
EPA finding on the caries association is consistent with NRC (2006)
that the ``available evidence is mixed but generally supportive''.
(Id. at 64).
b. Skeletal fluorosis. After reviewing the limited data available
on the
[[Page 3435]]
relationship between fluoride exposure and stage II skeletal fluorosis,
OW concluded that ``the currently available data are not sufficiently
robust to support a dose-response analysis of the effects of fluoride
in drinking water on the skeletal fluorosis.'' (Id. at 84).
Specifically, OW found that the limited data ``suggested that a daily
fluoride dose in excess of 10 mg may be required to produce signs of
stage II skeletal fluorosis (except possibly in the case of individuals
with renal disease).'' (Id. at 83). OW also noted that the NRC Report
called attention to the fact that a drinking water fluoride level of 4
mg/L can result in bone fluoride levels similar to those associated
with stage II or III skeletal fluorosis; however, OW concluded that
``because of inconsistencies in the entire data set, it is unlikely
that bone fluoride concentration can be used in a dose-response
analysis of skeletal fluorosis.'' (Id. at 65).
c. Bone fractures. OW found that more data were available on
fluoride's potential effect on bone fractures than skeletal fluorosis.
OW concluded that these data (1) ``in general, support the conclusions
of NRC that relative risk of fracture increases with increasing
fluoride concentration * * *.'' (Id. at 84); and (2) ``indicate[ ] that
exposure to concentrations of fluoride in drinking water of 4 mg/L and
above is suggestive of and appears to be positively associated with
increased relative risk of bone fractures in susceptible populations
when compared to populations exposed to 1 mg F/L.'' (Id. at 86).
Nonetheless, OW also determined that ``there is no clear evidence that
fluoride will cause * * * bone fractures at levels as low as those
associated with severe dental fluorosis.'' (Id. at 86). In a parallel
to fluoride's effect on the frequency of dental caries, OW noted that
there are some data suggesting that there is a U-shaped dose-response
curve for fluoride's effect on the risk of bone fracture. Agreeing with
the NRC Report, OW stated that fluoride in drinking water at 1 mg/L may
result in a reduction of bone fractures compared to either higher or
lower fluoride exposures. (Id. at 84).
d. Quantification of dose response. OW's examination of the data on
severe dental fluorosis, stage II skeletal fluorosis, and bone
fractures led it to conclude that severe dental fluorosis was the
adverse effect due to fluoride exposure likely to occur at the lowest
exposure level. (Id. at 87). As indicated previously, OW also
identified the 1942 Dean study as presenting the most useful data for
conducting a dose-response assessment. (Id.). To confirm the
appropriateness of using the data from the Dean study for a dose-
response analysis, OW analyzed the data under a statistical procedure
known as categorical analysis. That analysis showed that ``fluoride
concentration in this dataset is significantly and positively
associated with severity of effect ([chi]2 = 1101.86, p <0.0001).''
(Id. at 89). OW then used the Benchmark Dose approach to compute a
benchmark dose (BMD) and a benchmark dose confidence limit (BMDL) for
severe dental fluorosis at various severe dental fluorosis response
rates. The lowest response rate of severe dental fluorosis within the
range of probability that the dataset could support was severe dental
fluorosis affecting at least 0.5% of the population exposed to fluoride
at a particular level in drinking water. (Id. at 90-91). At a severe
dental fluorosis response rate of 0.5%, the BMD for the concentration
of fluoride in drinking water was 2.14 mg/L and the BMDL was 1.87 mg/L.
OW ran various sensitivity analyses to confirm these results including
comparing them to the NOAEL/LOAEL approach. These analyses supported
the use of the BMDL from the Dean study data.
To establish a RfD, it was necessary to convert the 1.87 mg/L
fluoride concentration in drinking water into an exposure value in
terms of milligram of exposure per kilogram of body weight per day (mg/
kg/day) and to take into account any other sources of fluoride exposure
(also in terms of mg/kg/day). Because the Dean study did not record
drinking water intakes or body weight, OW converted the 1.87 mg/L level
using more recent data on drinking water intake and body weight. OW
calculated exposure values from consumption of drinking water
containing 1.87 mg/L for different age groups of children and at
different levels of water intake within those age groups. After
examining the range of values produced by this exercise, OW chose the
value of 0.07 mg/kg/day as the contribution of drinking water to the
fluoride RfD at the time of the Dean (1942) study (values ranged from
0.04 mg/kg/day to 0.19 mg/kg/day). That value was chosen because it was
the most protective value assuming average water intake that provided
some margin of safety above the IOM's minimum adequate intake level for
fluoride of 0.05 mg/kg/day. (Id. at 101-102). OW concluded that the
only other meaningful fluoride exposure at the time of the Dean study
was from fluoride in food and OW estimated that exposure level to be
0.01 mg/kg/day based on data collected in the same time period of the
Dean study. (Id. at 104). Combining these two values yields 0.08 mg/kg/
day. Because the 0.08 mg/kg/day value only marginally exceeds the
adequate intake value of fluoride and the value was primarily derived
from a human study with a large sample size, OW determined that no
safety or uncertainty factors were needed in computing the RfD for
fluoride. (Id. at 105-106) Thus, 0.08 mg/kg/day was chosen as the
fluoride RfD. Although the RfD is based on the endpoint of severe
dental fluorosis in children, OW concluded that ``the RfD is applicable
to the entire population since it is protective for the endpoints of
severe fluorosis of primary teeth, skeletal fluorosis and increased
risk of bone fractures in adults.'' (Id. at 107).
OW described its confidence in the RfD as ``medium.'' (Id.). OW's
degree of confidence turned on its analysis of the data in the Dean
study. On one hand, OW noted that the Dean study was:
Internally consistent as evidenced by the BMD stability
when end points at the high and low end of the curve were removed,
Supported by later studies on some of the same water
sources showing similar concentrations,
Used average concentration values from 12 consecutive
months for all but the three systems with the highest prevalence of
severe dental fluorosis, thereby compensating for potential individual
and seasonal variation,
Based on water quality data from the same time period, and
not likely to have been compromised by high levels of interfering
substances.
(Id. at 106-107) On the other hand, OW found that some uncertainty
flowed from its reliance on the Dean study because of the difficulties
encountered in converting the concentration-response data to dose
estimates for the RfD derivation. (Id. at 107).
2. Exposure assessment. In evaluating exposure to fluoride, OW
focused on the following potentially significant sources:
Drinking water from public drinking water systems;
Solid foods and beverages such as milk and juices not from
concentrate;
Residues from the use of sulfuryl fluoride;
Beverages prepared with commercial water which in some
cases may have been fluoridated;
Infant formula made from powdered concentrate;
Toothpaste; and
Incidentally ingested soil.
OW determined fluoride exposure from ambient air, dietary supplements,
dental treatments, and pharmaceuticals was
[[Page 3436]]
minimal or too episodic to be of consideration for assessing long-term
exposure. (Ref. 22).
OW evaluated fluoride levels in drinking water based on the largest
and most comprehensive set of drinking water compliance monitoring data
ever compiled and analyzed by the Agency. The data include records from
approximately 136,000 public drinking water systems, many of which
include reports of fluoride concentrations. The data span 8 years
(1998-2005), with up to quarterly sample analysis for fluoride,
depending on the system and reporting requirements. This amounts to
approximately 7,000 to 12,000 quarterly samples depicting fluoride
residues. There was an increase in the number of States reporting for
the subset of data from 2002-2005; therefore, OW focused on those data
when estimating exposure to fluoride from drinking water. For that time
period, the average of the quarterly means is 0.87 ppm and the average
for the quarterly 90th percentile values is 1.43 ppm. OW has also sub-
sampled the monitoring data to focus on systems that had at least one
detection equal to or greater than 2 ppm fluoride. Those systems
represent 4.6 to 8.3% of the reporting systems, annually, during the
2002-2005 time frame and, over the 4-year reporting period, served
approximately 10 million people. For water consumption information, OW
relied on data from the CSFII for those consumers reporting consumption
of drinking water. OW estimated fluoride exposure amounts for mean and
90th percentile consumers of drinking water from public systems
considering both mean and 90th percentile fluoride levels. These values
ranged from 0.26 mg/day for infants (mean consumption (all consumers),
mean fluoride value) to 1.99 mg/day for adults (90th percentile
consumption (consumers-only and mean fluoride level . (Ref. at 68-69,
Tables 3-5 and 3-6). For 90th percentile consumers consuming mean
fluoride levels, the values ranged from 0.63 mg/day for children 1 to 3
years old to 1.74 mg/day for adults. (Id. at 94, Table 6-3).
For exposure to fluoride from food, milk, and non-concentrated
juices, OW relied on market basket data, dietary surveys, and national
food consumption data, for various age groups. OW estimated that
fluoride exposure from these sources ranged from 0.25 mg/day for
infants to 0.47 mg/day for teenagers. (Id. at 90, Table 6-1).
Fluoride exposure from residues of sulfuryl fluoride in food was
estimated by OPP based on usage data and residue data relevant to both
sulfuryl fluoride's use as a direct commodity fumigant and as a
structural fumigant. Estimated exposure values ranged from 0.03 mg/day
for infants to 0.09 mg/day for children 7 to 10 years old. (Id. at 96,
Table 6-5).
OW estimated fluoride exposure from beverages other than milk and
non-concentrated juices from various studies and national consumption
data, where appropriate. Fluoride exposure levels from beverages ranged
from 0.36 mg/day for 1-<4 year olds to 0.60 mg/day for 7 to 11 year
olds. (Id. at 92, Table 6-2).
Fluoride exposure from toothpaste was estimated by OW using studies
that measure fluoride intake by subtracting the amount of toothpaste
left on the toothbrush after brushing and the amount expectorated from
the amount initially placed on the toothbrush. OW found a high level of
uncertainty with these data because ``the confidence bounds around the
mean values are indicative of high inter-individual variability,'' and
because the studies were conducted not long after release of FDA
recommendations ``for children to use only a pea-sized amount of
toothpaste when brushing.'' (Id. at 94). OW also relied on data showing
that generally young children only brushed their teeth once per day.
Toothpaste label directions send different signals on this point, both
recommending for children 2 years of age and older that teeth should be
brushed ``preferably after each meal or at least twice a day'' and
stating that for younger children a dentist or doctor should be
consulted. 21 CFR 355.50(d)(1). Estimated fluoride exposure values
ranged from 0.07 mg/day for 0.5 to 1 year olds to 0.34 mg/day for 1 to
4 year olds. (Id. at 94, Table 6-4).
OW concluded that other sources of fluoride exposure (e.g., air,
dental treatments) were insignificant with the exception of exposure to
children through consumption of soil. Fluoride concentrations in the
soil in the United States range from less than 10 ppm to 70,000 ppm,
with mean or typical levels in the 300-430 ppm range. (Id. at 86).
Assuming mean levels of fluoride in the soil, OW estimated fluoride
exposure for children less than 1 year old to be 0.02 mg/day and for
children in the 0-14 age group to be 0.04 mg/day. (Id. at 95).
3. Risk characterization. In characterizing the risk from fluoride
for the purpose of evaluating the fluoride MCLG, OW compared the
revised fluoride RfD (0.08 mg/kg/day) to the significant sources of
fluoride exposure described previously. OW used average exposure values
as to all sources of exposure other than drinking water. For drinking
water, OW, examined several different variations of concentration level
and consumption level, but principally relied on the approach in long-
held OW policy in establishing national drinking water standards that
recommends use of average fluoride concentrations in water and 90th
percentile consumption levels. (Id. at 107-110). OW's characterization
of risk using these assumptions is shown in Figure 1.
[[Page 3437]]
[GRAPHIC] [TIFF OMITTED] TP19JA11.047
(Id. at 105, Figure 8-1).
OW explained the meaning of Figure 1 in the following manner:
When examining Figure [1] it is important to remember that the
RfD represents an exposure that is estimated to provide the
anticaries benefits from fluoride without causing severe dental
fluorosis in 99.5% of the children who drink water with 0.87 mg/L F
at a 90th percentile intake level and have average intakes from
other media during the period of secondary tooth formation. Based on
the dose-response for severe dental fluorosis in EPA (2010a) only
0.5% or fewer of children consistently ingesting fluoride at a level
equivalent to the RfD for a several month period would be at risk of
experiencing severe dental fluorosis in two or more teeth.
(Id. at 104-105).
OW noted that the data show both that fluoride exposure has
increased over time and that the incidence of all types of dental
fluorosis has also increased. According to OW, ``The prevalence of
dental fluorosis has increased from 10-12% in the areas with about 1
mg/L in drinking water at the time of Dean to 23% in 1986/87 and to 32%
in the 1999-2002 NHANES survey.''
(Id. at 108) (citations omitted).
OW summarized its overall conclusions as follows:
Some young children are being exposed to fluoride up to
about age 7 at levels that increase the risk for severe dental
fluorosis.
The contribution of residential tap water to total
ingested fluoride is lower that it was in the past.
Use of fluoridated water for commercial beverage
production has likely resulted in increased dietary fluoride in
purchased beverages, adding to the risk for over-exposure.
The increase of fluoride in solid foods because of
fluoridated commercial process water is more variable than that for
beverages.
Incidental toothpaste ingestion is an important source of
fluoride exposure in children up to about 4-years of age. However, use
of fluoridated toothpaste is not recommended for children under age 2
according to FDA guidance and package labeling suggesting the need for
greater parental awareness of the FDA (2009) recommendations.
Ambient air, soils, and sulfuryl fluoride residues in
foods are minor contributions to total fluoride exposure. (Id. at 108-
109).
B. OPP's Revised Fluoride Risk Assessment
In light of the revised fluoride risk assessment by EPA's OW, EPA's
OPP has conducted a revised aggregate assessment of fluoride exposure
and risk under FFDCA section 408. (Ref. 23). EPA is inviting public
comment on all aspects of the revised aggregate assessment.
1. Hazard/dose-response assessment. OPP agrees with OW's choice of
severe dental fluorosis as the endpoint for assessing chronic risk from
fluoride exposure. As noted, both OW and OPP had treated several dental
fluorosis as a cosmetic effect and not an adverse health effect.
Following the NRC Report and the re-examination of this issue by both
OW and OPP, EPA has concluded that severe dental fluorosis is an
adverse effect due to the fact that the pitting it causes in the
permanent teeth is a structural defect to the teeth. As OW's analysis
explains:
Pitting of the enamel is a structural defect that weakens the
barrier between the oral environment and the dentin of the teeth. It
is progressive in that the enamel can flake off from the sides of
the pits allowing them to become progressively larger. Furthermore,
the dentin of teeth with severe dental
[[Page 3438]]
fluorosis is hypomineralized and structurally variant increasing the
importance of the enamel's protective function.
(Ref. 21 at 64) (citations omitted).
OPP also agrees with OW's choice of 0.08 mg/kg/day as a NOAEL for
severe dental fluorosis relying on the Dean study, and the use of that
value as a Point of Departure for calculating the RfD. Further, OPP
concurs that neither an inter- or intra-species safety factor should be
used in the RfD calculation. An inter-species factor is unnecessary
because the endpoint is from a human epidemiological study; an intra-
species factor is not needed given the extensiveness of the data and
the fact that it studied the subpopulations of concern, children of
different ages.
Given these findings, OPP concludes that the Objectors were correct
in contesting the reliance on the endpoint of crippling skeletal
fluorosis to set a RfD for fluoride. OPP agrees that the RfD should be
based on a more sensitive endpoint--severe dental fluorosis. It follows
that the Objectors were also correct to object to use of children-
specific RfD values based on the endpoint of crippling skeletal
fluorosis. A RfD based on the Dean study is appropriate for children,
however, because such a RfD is derived from data on the effects of
fluoride on children.
2. Exposure assessment. OPP's revised exposure analysis depends
heavily on OW's Relative Source Contribution Analysis. A brief
description of how that data and analysis have been incorporated into a
FFDCA section 408 risk assessment is provided in the following
sections.
a. Fluoride from sulfuryl fluoride. In the exposure assessments for
the 2004 and 2005 tolerance actions, EPA conducted a somewhat refined
exposure assessment of fluoride exposure in food from use of sulfuryl
fluoride as both a commodity fumigant and as a structural fumigant for
food handling facilities. Taking into account comments OPP has received
from Dow AgroSciences, OPP has further refined this aspect of the
exposure assessment. (Ref. 24). The three main refinements are:
(1) OPP used a regression analysis to estimate residue values of
fluoride in food that occur from actual use rates rather than assuming
residue values as measured under maximum application rates;
(2) OPP used a probabilistic analysis to estimate residues
resulting from possible sequential treatment of food (e.g., fumigation
of raw commodity, incidental treatment during fumigation of structure,
fumigation of the processed commodity) rather than conservatively
assuming that 100% of food was sequentially treated; and
(3) OPP used more extensive data on the percent of food treated
with sulfuryl fluoride. EPA used methyl bromide usage as the basis for
estimating the percent usage of sulfuryl fluoride because sulfuryl
fluoride was introduced as a replacement for methyl bromide. The
refinements to this aspect of the exposure assessment result in a
reduction of estimated exposure values to fluoride from sulfuryl
fluoride use of roughly an order of magnitude.
Consistent with its well-established practice for chronic exposure
assessments, OPP assessed exposure to fluoride residues in food based
on average residue values and average food consumption values. Given
the national food distribution patterns in the United States, exposure
to foods with different residue levels average out over time. Further,
because different people eat different foods in different amounts, it
would dramatically overstate exposure to assume that a single person
consumed all foods at a high end consumption value. The revised
exposure values for fluoride from sulfuryl fluoride are presented in
Table 1.
Table 1--Summary of Sulfuryl Fluoride Contributions to Dietary Fluoride Exposure
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average estimated exposure (mg/day) Average estimated exposure mg/kg/day
-----------------------------------------------------------------------------------------------------------
Age range, years SF structural SF structural
\a\ SF food \b\ Total \a\ SF food \b\ Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.5-<1...................................... 0.0087 0.021 0.030 0.0008 0.0019 0.0027
1-<4........................................ 0.012 0.033 0.045 0.0008 0.0022 0.0030
4-<7........................................ 0.015 0.047 0.062 0.0007 0.0022 0.0029
7-<11....................................... 0.017 0.054 0.071 0.0005 0.0017 0.0022
11-<14...................................... 0.018 0.068 0.086 0.0004 0.0014 0.0018
14+......................................... 0.019 0.058 0.076 0.0003 0.0008 0.0011
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Reflecting residues resulting from fumigation of structures that may contain human food products.
\b\ Reflecting residues resulting from intentional fumigation of human foods.
(Ref. 23 at 10, Table 1).
b. Fluoride from cryolite. Previously, OPP estimated fluoride
exposure from use of the pesticide cryolite using residue data from
cyrolite field trials and data on the percent of food treated with
cryolite. Since cryolite has been in use for years, cryolite residues
in food are captured by the monitoring data OW collected on fluoride
data in food generally. As discussed in the next section, OPP is using
this monitoring data in its exposure assessment and thus a separate
assessment of fluoride from cryolite would result in double-counting.
c. Fluoride in food and beverages. OPP is relying on the
comprehensive OW analysis of the extensive fluoride monitoring data in
published literature in estimating fluoride exposure from foods and
beverages. The food monitoring data predates sulfuryl fluoride use and
thus does not capture those residue levels. Consistent with how it
conducts chronic exposure assessments for pesticide residues in food,
OPP has used central-tendency values in estimating exposure. Exposure
estimates for fluoride from background levels in food (including
cryolite residues) and in prepared beverages are presented in Table 2.
[[Page 3439]]
Table 2--Summary of Estimated Fluoride Exposures Attributable to Background Levels in Food and Beverages
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated fluoride exposure (mg/day) Estimated fluoride exposure (mg/kg/day)
Age range, years Body weight, -----------------------------------------------------------------------------------------------
kg Solid food \*\ Beverages Total Solid food \*\ Beverages Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.5-<1.................................. 9 0.26 \*\ 0.26 0.029 \*\ 0.029
1-<4.................................... 14 0.16 0.36 0.52 0.011 0.026 0.037
4-<7.................................... 21 0.35 0.54 0.89 0.017 0.026 0.042
7-<11................................... 32 0.41 0.60 1.01 0.013 0.019 0.032
11-<14.................................. 51 0.47 0.38 0.85 0.0092 0.0075 0.017
14+..................................... 70 0.38 0.59 0.97 0.0054 0.0084 0.014
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Solid food includes milk as well as fruit and vegetable juices not made from concentrate. These are not categorized as beverages in the FDA Total Diet
Study (Egan et al., 2007). For the age range 0.5-<1 year, all fluoride was considered to be from powdered formula and falls into the food category.
(Ref. 23 at 15, Table 6).
d. Fluoride from public drinking water systems. People are exposed
to fluoride from public drinking water both by direct consumption of
the water and from indirect consumption of the water after its use in
the preparation of foods and beverages in the home. References in this
section to drinking water exposure are intended to capture both of
these types of exposure. Exposure to fluoride from water containing
fluoride residues that is used in the commercial preparation of food
and beverages is accounted for in the estimates of fluoride in food and
beverages. (See Unit V.B.2.c). To estimate exposure, OPP has coupled
average, per-capita consumption from the CSFII with the fluoride
concentrations for the water systems described previously. The CSFII
consumption estimates include drinking water (direct water) and water
used for in-home preparation of foods and beverages (indirect water).
In the earlier exposure assessments, OPP assumed that fluoride in
drinking water was present at 2 mg/L. Extensive monitoring data on
fluoride levels in drinking water, however, have now been collected and
analyzed by OW in conducting its Relative Source Analysis in response
to the NRC Report. OPP has relied on these data in estimating exposure.
(Ref. 23 at 10-15).
Generally, OPP estimates pesticide exposure from drinking water by
focusing on watersheds that are likely to have high end residue levels.
This approach is based on several factors. First, pesticide residues in
watersheds can have widely different values based on their regional
relationship with agricultural areas and environmental factors (e.g.,
soil type, rainfall amount). Second, consumption of drinking water,
unlike food, is mainly a local phenomenon--i.e., tap water is not an
amalgam from drinking water systems around the country. Thus, focusing
on watersheds with high-end residue levels is critical to fulfilling
EPA's statutory obligation to consider aggregate exposure to ``major
identifiable subgroups of consumers * * *.'' (21 U.S.C.
346a(b)(2)(D)(vi)). Accordingly, in the first instance, OPP has used
OW's drinking water monitoring data to identify drinking water systems
with high-end fluoride levels. OPP has focused on water systems that
have had at least one measured fluoride value of greater than 2 mg/L,
at least one measured value of greater than 3 mg/L, and at least one
measured value of greater than 4 mg/L. These groupings of water systems
were used because of the significant population groups served by these
systems--from well over 1 million to roughly 10 million. OPP believes
it is reasonable to use average monitoring values from these groups of
water systems because of the relative stability of fluoride levels in
water. Importantly, these average values bracket OPP's prior assumption
of 2 mg/L with the average values ranging from 1.76 mg/L to 2.58 mg/L.
Given the unusual circumstances of fluoride--not only are there
multiple sources in addition to pesticidal sources but several sources
are the result of intentional actions designed to result in wide-spread
national exposure--OPP believes that OW's approach to assessing
fluoride exposure in its Relative Source Analysis under SDWA has
relevance to its aggregate exposure analysis under FFDCA section 408.
OW's Relative Source Analysis focuses on high-end water consumers who
are exposed to average exposures calculated on a national basis.
Because the population concerned here is so large, roughly 300 million
people, even looking at high-end consumers (OW's traditional approach
is to use the 90th percentile) represents consideration of a large
population subgroup.
Table 3 provides exposure estimates for fluoride in drinking water
from both OPP and OW approaches.
Table 3--Fluoride Exposure Estimates (mg/kg/day) From Municipal Water \1\
----------------------------------------------------------------------------------------------------------------
Fluoride concentration in drinking water (mg/L); consumption percentile
Age range, years -------------------------------------------------------------------------
0.87 90th 1.76 Average 2.28 Average 2.59 Average
----------------------------------------------------------------------------------------------------------------
0.5-<1................................ 0.093 0.077 0.10 0.11
1-<4.................................. 0.045 0.040 0.052 0.059
4-<7.................................. 0.039 0.033 0.043 0.049
7-<11................................. 0.027 0.024 0.031 0.035
11-<14................................ 0.024 0.018 0.024 0.027
14+................................... 0.025 0.026 0.033 0.038
----------------------------------------------------------------------------------------------------------------
\1\ Includes drinking water as well as water for in-home preparation of foods and beverages. Estimates are based
on 90th percentile consumer only or average per capita consumption, as indicated, and do not include fluoride
from toothpaste, from soil, or from sulfuryl fluoride.
[[Page 3440]]
(Ref. 23 at 11, Table 3; 14, Table 5).
e. Fluoride from toothpaste. OW has comprehensively reanalyzed the
data on fluoride exposure from toothpaste taking into consideration all
available studies. The results of that analysis are presented in Table
4.
Table 4--Summary of Estimated Fluoride Exposures From Incidental Ingestion of Fluoridated Toothpaste
----------------------------------------------------------------------------------------------------------------
Estimated fluoride exposure Estimated fluoride exposure (mg/
(mg/day) kg/day*)
Age range, years -------------------------------------------------------------------
1 brushing 2 brushings 1 brushing per 2 brushings per
per day per day day day
----------------------------------------------------------------------------------------------------------------
0.5-<1...................................... 0.07 0.14 0.0078 0.016
1-<4........................................ 0.34 0.68 0.024 0.049
4-<7........................................ 0.22 0.44 0.010 0.021
7-<11....................................... 0.18 0.36 0.0056 0.011
11-<14...................................... 0.2 0.4 0.0039 0.0078
14+*........................................ 0.1 0.2 0.0014 0.0029
----------------------------------------------------------------------------------------------------------------
* No data were available for this age group. The exposure estimate is one half that of the 11 to 14 year group.
(Ref. 23 at 16, Table 7).
OW was also able to identify limited data on the frequency of teeth
brushing by children. Those data are presented in Table 5.
Table 5--Number of Toothbrushings per Day Reported for Children (Six Months to Five Years Old)
----------------------------------------------------------------------------------------------------------------
Percentages *
Study N = Age (years) --------------------------------------
1 time/day 2 times/day 3 times/day
----------------------------------------------------------------------------------------------------------------
Simard et al., 1989.......................... 23 2 to 5 4.8 71.4 23.8
Simard et al., 1991.......................... 15 1 to 2 60 32 8
Levy et al., 1997............................ 899 0.5 41.2 16.9 6.3
665 0.75 33.2 17 3.1
508 1 37 14.7 3.5
Franzman et al., 2006........................ 90 1.3 48 14 4
100 2 51 23 2
100 3 51 24 1
----------------------------------------------------------------------------------------------------------------
* Some studies also reported those brushing their teeth less than once per day and more than three times per
day. In these cases the percentages do not add up to 100%.
(Ref. 22 at 81, Table 4-10). Based on the fact that a substantial
portion of children brush two or more times per day and that brushing
twice per day is consistent with health care recommendations, OPP is
assuming two brushings per day in its assessment.
f. Fluoride from soil. Young children are exposed to fluoride from
inadvertent consumption of soil. OPP estimated fluoride exposure from
soil using standard EPA estimates on soil consumption and assuming
average fluoride residues in soil. These estimates are presented in
Table 6.
Table 6--Summary of Estimated Fluoride Exposures From Incidental
Ingestion of Soil and Outdoor Dust
------------------------------------------------------------------------
Estimated Estimated
fluoride fluoride
Age range, years exposure * (mg/ exposure * (mg/
day) kg/day)
------------------------------------------------------------------------
0.5-<1.................................. 0.02 0.0022
1-<4.................................... 0.04 0.0029
4-<7.................................... 0.04 0.0019
7-<11................................... 0.04 0.0013
11-<14.................................. 0.04 0.00078
14+..................................... 0.02 0.00029
------------------------------------------------------------------------
* Assumes soil and dust contains 400 ppm fluoride.
(Ref. 23 at 17, Table 8).
g. Other sources of fluoride exposure. Although people are also
potentially exposed to fluoride from fluoride in ambient air, fluoride
dental treatments, and pharmaceuticals, among other things, OW
concluded that these sources of exposure are insignificant compared to
other sources of fluoride exposure. Accordingly, OPP is not including
such exposures in its aggregate assessment. (Ref. 23 at 16).
3. Children's safety factor. In choosing a revised RfD for
fluoride, OW did not apply any uncertainty or safety factors to the
BMDL for severe dental fluorosis. OW reasoned that uncertainty factors
were not warranted due to the extensive human epidemiological data on
the effects of fluoride, including extensive data on children, the
population of greatest concern. Decisions on pesticide tolerances,
however, require OPP to apply special provisions for protection of
children. Specifically, section 408(b)(2)(C) of FFDCA provides that EPA
shall apply an additional tenfold (10X) margin of safety for infants
and children in the case of threshold effects to account for prenatal
and postnatal toxicity and the completeness of the database on toxicity
and exposure unless EPA determines based on reliable data that a
different margin of safety will be safe for infants and children. In
making determinations on this children's safety factor, OPP has focused
on the statutory factors of data completeness with regard to toxicity
and exposure and evidence bearing on pre- and post-natal toxicity.
As with so many other aspects of the fluoride risk assessment,
application of
[[Page 3441]]
the children's safety factor provision to fluoride presents unique
issues. OPP considered the following factors in determining whether
reliable data show that an additional safety factor other than the
default 10X value would be safe:
a. Toxicity data. As a result of the decades-long water
fluoridation program in the United States as well as the substantial
areas with high natural levels of fluoride in drinking water, OPP has
an epidemiological dataset for fluoride that is far more extensive than
for any other pesticide. EPA also has an extensive set of animal data
on sulfuryl fluoride and to the extent that sulfuryl fluoride breaks
down to the fluoride anion during testing, these studies capture the
effects of fluoride (dental fluorosis was observed in a number of
studies). On the other hand, OPP has recently requested additional
studies on sulfuryl fluoride, a developmental neurotoxicity study and
an immunotoxicity study, and the NRC Report identified several areas,
notably brain and endocrine effects, where further study would be
useful. On the whole, however, OPP concludes that the completeness of
the database with regard to fluoride exceeds what is generally
available even on the most well-studied pesticides.
b. Exposure data. OPP has an extremely extensive database on
fluoride levels in drinking water due to the water monitoring data OW
has collected. OPP also has reliable data on fluoride exposure from
sulfuryl fluoride and on background levels of fluoride in food. To the
extent sulfuryl fluoride has not replaced methyl bromide as a fumigant
the fluoride estimate from sulfuryl fluoride overstates exposure. There
is some uncertainty as to the amount of fluoride exposure from
toothpaste. There are several factors here: Data on fluoride exposure
from toothpaste are less extensive and are highly variable; the data
may not reflect the latest recommendations on the amount of toothpaste
children should use; label directions for adults and children 2 years
old and above state that teeth should be brushed ``thoroughly,
preferably after each meal or at least twice a day;'' and label
directions for children below 2 years of age state that a dentist or
doctor should be consulted. However, by assuming two brushings per day
and relying on studies that may have used greater amounts of toothpaste
than is used today as well as focusing on high-end exposure groups for
drinking water, OPP believes it has addressed any uncertainties
regarding fluoride exposure from toothpaste.
c. Pre- and post-natal toxicity. Not only does OPP have extensive
data identifying fluoride's effects in humans and the dose at which
those effects occur, but fluoride, unlike most pesticides or their
metabolites, is considered a human nutrient. Fluoride's classification
as a nutrient--especially its role at certain doses in protecting
teeth--cannot be ignored in the safety factor calculation. OPP is
averse to choosing a safety factor that would result in the choice of a
PAD that indicates that fluoride is harmful at levels below the
adequate intake level for beneficial effects. The Objectors have raised
concerns about potential other effects of fluoride--for example, brain,
endocrine, kidney, and reproductive effects. Nonetheless, data on these
effects generally either shows effects only at considerably higher
levels than the levels causing severe dental fluorosis or are very
equivocal.
On balance, the extensiveness of the data on toxicity of fluoride
and human exposure to it, the clear data defining the safe level for
the effect of concern on children, and fluoride's status as a human
nutrient at levels only slightly below the level that is protective
against severe dental fluorosis lead OPP to conclude that reliable data
show that an additional safety factor for the protection of children is
not necessary. Accordingly, OPP has not used an additional safety
factor in its fluoride risk assessment. Hence, the PAD for fluoride is
equivalent to the RfD (0.08 mg/kg/day). (Ref. 23 at 9).
4. Risk characterization. To characterize the risk of fluoride, OPP
has aggregated exposure to fluoride from sulfuryl fluoride, background
levels in food (including from cryolite), beverages, drinking water,
toothpaste, and soil, and compared that aggregated exposure to the PAD.
In evaluating exposure to major identifiable subgroups of consumers,
OPP believes that for fluoride it is appropriate to consider the
aggregate exposure of at least four different subgroups:
a. Communities served by a water system with at least one sample
showing fluoride levels greater than 2 mg/L (2 mg/L communities);
b. Communities served by a water system with at least one sample
showing fluoride levels greater than 3 mg/L (3 mg/L communities);
c. Communities served by a water system with at least one sample
showing fluoride levels greater than 4 mg/L (4 mg/L communities); and
d. High-end water consumers generally.
The aggregate exposure of these subgroups relative to the RfD/PAD
is shown in Table 7:
Table 7--Aggregate Exposure Compared to RfD by Age Groups (mg/kg/day)
--------------------------------------------------------------------------------------------------------------------------------------------------------
High-end water
Age groups RfD/PAD consumers 2 mg/L community 3 mg/L community 4 mg/L community
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.5-<1.................................................... 0.08 0.13 0.13 0.15 0.16
1-<4...................................................... 0.08 0.11 0.13 0.14 0.15
4-<7...................................................... 0.08 0.097 0.10 0.11 0.12
7-<11..................................................... 0.08 0.068 0.070 0.077 0.081
11-<14.................................................... 0.08 0.047 0.045 0.051 0.054
14+....................................................... 0.08 0.042 0.044 0.051 0.056
--------------------------------------------------------------------------------------------------------------------------------------------------------
(Ref. 23 at 21, Table 9).
This risk assessment shows that aggregate fluoride exposure to
young children exceeds the RfD/PAD under various different methods of
identifying major population subgroups. In evaluating this assessment
at least two other factors are relevant. First, the assessment of the
2-4 mg/L communities deviates from OPP's traditional approach to
assessing exposure in drinking water in that it averages exposures from
systems that are surface water-based and systems that are groundwater-
based. EPA generally assesses drinking water exposure on the higher
value from surface water or groundwater because people get the majority
of their drinking water exposure from one location. For fluoride,
focusing only on groundwater-based systems would modestly increase the
exposure estimate. Second, this assessment does not take into account
those people that depend on private drinking water wells and not public
drinking water systems. Drinking water
[[Page 3442]]
wells in certain portions of the United States can have fluoride levels
exceeding those used in the assessments discussed previously.
Based on these assessments, EPA cannot conclude that there is a
reasonable certainty of no harm for certain major identifiable groups
of consumers from aggregate exposure to fluoride. Therefore, EPA cannot
make the required finding that the sulfuryl fluoride and fluoride
tolerances are ``safe'' and is proposing to grant the Objectors'
objections to the establishment of the sulfuryl fluoride and fluoride
tolerances promulgated on January 23, 2004, and July 15, 2005.
C. Comments From Dow AgroSciences
As noted previously, Dow AgroSciences has filed comments contesting
the Objectors' claims regarding the safety of fluoride. First, Dow
AgroSciences argues that the Objectors have only potentially shown that
small, localized groups of people are exposed to unsafe levels of
fluoride and such small groups do not constitute a ``major
identifiable'' subgroup under FFDCA. EPA disagrees with Dow
AgroSciences that the groups of people exposed at levels that exceed
the RfD are not major identifiable subgroups of consumers. As noted
previously, the subgroups OPP relies upon include at least 1 million,
and in some cases, many millions of people. Although the individuals
within these subgroups facing unacceptable risks from aggregate
fluoride exposure are limited to infants and children up to the age of
7, the persons at risk remain substantial.
Second, Dow AgroSciences challenges whether the NRC Report showed
that there is a more sensitive endpoint than crippling skeletal
fluorosis. Dow AgroSciences' comments on this issue focused on the
endpoints of bone fracture, stage II skeletal fluorosis, and severe
dental fluorosis.
1. Bone fracture. Dow AgroSciences argued that the NRC Report did
not place sufficient weight on a 2005 observational study from the
University of Michigan (Sowers) and placed too much weight on two other
studies (Alarcon and Li) that were judged unreliable by OPP. OW
undertook a comprehensive review of all of the available data. Like
NRC, it found certain weaknesses in the 2005 Sowers study but overall
considered it along with the Li study and several other studies to be
one of the key studies for assessing the risk of bone fractures. The
Alarcon study was given less weight. Also similar to the NRC Report, OW
concluded that ``the available data indicate that exposure to
concentrations of fluoride in drinking water of 4 mg/L and above is
suggestive of and appears to be positively associated with increased
relative risk of bone fractures in susceptible populations when
compared to populations exposed to 1 mg mg/L.'' (Ref. 21 at 86). OW
also noted, however, that ``there are insufficient data to conclude
that this increase in relative risk would also apply if comparisons
were made to groups exposed to negligible fluoride concentrations or if
comparisons were made based on total fluoride intake rather than on the
basis of drinking water concentrations.'' (Id.). Ultimately, OW
concluded that the fluoride RfD should be based on severe dental
fluorosis and that this endpoint was protective of any risk of bone
fractures and thus a more definite resolution of this issue is
unnecessary.
2. Stage II skeletal fluorosis. Dow AgroSciences emphasized that
the NRC Report's finding on fluoride's link to stage II skeletal
fluorosis were equivocal. OW's conclusions on stage II skeletal
fluorosis were similar to those of NRC. OW found that ``[t]he results
of the limited epidemiological studies and case histories suggest that
a daily fluoride dose in excess of 10 mg may be required to produce
signs of stage II skeletal fluorosis (except possibly in the case of
individuals with renal disease).'' (Ref. 21 at 83). But OW concluded
that ``the currently available data are not sufficiently robust to
support a dose-response analysis of the effects of fluoride in drinking
water on skeletal fluorosis.'' (Id.). As with risk of bone fractures,
because OW determined that the fluoride RfD should be based on severe
dental fluorosis and that this endpoint was protective of any risk of
stage II skeletal fluorosis, a more definite resolution of this issue
is unnecessary.
3. Severe dental flurosis. Dow AgroSciences challenged the
competency of NRC to make the legal conclusion that severe dental
fluorosis is an adverse health effect and also argued that there is
dispute within the scientific community regarding the adversity of
severe dental fluorosis. Without question, it is EPA that is charged
with interpreting SDWA and making legal findings in implementation of
that Act. Nonetheless, EPA does not view NRC as stepping beyond its
scientific advisory role in its report. OW has previously defined
adverse health effects as involving functional impairment and NRC
focused on whether the data showed functional impairment in reaching a
conclusion on whether severe dental fluorosis is an adverse health
effect. For example, the NRC Report states:
One of the functions of tooth enamel is to protect the dentin
and, ultimately, the pulp from decay and infection. Severe enamel
fluorosis compromises this health-protective function by causing
structural damage to the tooth. The damage to teeth caused by severe
enamel fluorosis is a toxic effect that the majority of the
committee judged to be consistent with prevailing risk assessment
definitions of adverse health effects.
(Ref. 17 at 127) (emphasis added).
Finally, while there may be a dispute within the scientific
community about how to characterize the adversity of severe dental
fluorosis, there does not appear to be any significant dispute over the
science question of whether severe dental fluorosis results in the
pitting of dental enamel. As Dow AgroSciences has pointed out, it is
EPA's responsibility to make the legal determination of whether this
effect should be categorized as an adverse health effect.
Third, Dow AgroSciences argues that EPA is not authorized to
aggregate fluoride added to drinking water for therapeutic purposes
with fluoride from sulfuryl fluoride because fluoride from water
fluoridation is neither a ``pesticide chemical'' under FFDCA nor an
``other related substance.'' Dow AgroSciences claims that FFDCA's
reference to ``other related substances'' means other related
``pesticidal'' substances. EPA disagrees with Dow AgroSciences'
interpretation of FFDCA section 408 for several reasons. First, there
is no exclusion from the aggregate exposure requirements for substances
that have a therapeutic effect at certain levels. Second, there is no
serious dispute that at certain levels exposure to fluoride is not
therapeutic but harmful, and Dow AgroSciences cannot be contending that
exposure to fluoride for water fluoridation does not aggregate within
the body with fluoride from other exposures. Third, a significant
portion of the U.S. population is exposed to fluoride in water that is
naturally-occurring rather than added for therapeutic purposes.
Finally, EPA has previously rejected attempts to limit the plain
meaning of ``other related substances'' and does not believe that Dow
AgroSciences has offered any compelling legal, policy, or scientific
reasoning for adopting an interpretation that would bar EPA from
considering the full effects of aggregate exposure to a substance. (See
69 FR 30042, 30073, May 26, 2004)(FRL-7355-7).
Dow AgroSciences also claims that EPA overestimated exposure to
fluoride from use of sulfuryl fluoride. EPA agrees with this comment
and, as described
[[Page 3443]]
previously, EPA has incorporated information from Dow AgroSciences on
sulfuryl fluoride usage in its sulfuryl fluoride/fluoride exposure
assessment.
VI. EPA's Proposed Response to Requests for Hearing
Because EPA is agreeing with the Objectors that the sulfuryl
fluoride tolerances do not meet the safety standard and is proposing to
grant their objections to the establishment of those tolerances, no
further action is needed with regard to the Objectors' hearing
requests. At this point, there is no material dispute of fact with
regard to the Objectors' claims that warrants a hearing.
VII. EPA's Proposed Response to Request for a Stay and EPA's Proposed
Expiration Date for Tolerances
Following release of the NRC Report, the Objectors filed a motion
with EPA requesting a stay of the sulfuryl fluoride tolerances. (Ref.
2). In arguing for a stay, the Objectors relied on the four factors
contained in Virginia Petroleum Jobbers Ass'n v. FPC, 259 F.2d 921 (DC
Cir. 1958):
(1) Has the petitioner made a strong showing that it is likely to
prevail on the merits;
(2) Has the petitioner shown that without such relief it will be
irreparably harmed;
(3) Would issuance of the stay substantially harm other parties
interested in the proceedings;
(4) Wherein lies the public interest.
In prior tolerance proceedings EPA has indicated it would consider
the criteria in FDA's regulations pertaining to stay requests. (See,
e.g., 61 FR 39528, 39540, July 29, 1996). Those regulations provide
that a stay shall be granted if a petitioner can show all of the
following:
(1) The petitioner will otherwise suffer irreparable injury.
(2) The petitioner's case is not frivolous and is being pursued in
good faith.
(3) The petitioner has demonstrated sound public policy grounds
supporting the stay.
(4) The delay resulting from the stay is not outweighed by public
health or other public interests.
(21 CFR 10.35).
The criteria under either approach are quite similar. Thus, in
evaluating the stay request EPA will concentrate on an amalgam of the
four factors:
What are the merits of the Objectors' claims;
Have the Objectors' shown that irreparable harm will occur
in the absence of a stay;
Would a stay substantially harm other parties or cause
other effects on the public health; and
Wherein lies the public interest.
EPA also believes that these factors are relevant in choosing an
effective date for its proposed grant of the objections.
A. Merits of the Objectors' Claims
As indicated, EPA agrees with the Objectors that the sulfuryl
fluoride tolerances do not meet the safety standard when aggregate
fluoride exposure is considered and thus this factor supports granting
the stay and making EPA's proposed grant of the objections effective
relatively quickly.
B. Irreparable Harm to Objectors
The Objectors argue that the public is irreparably harmed by the
sulfuryl fluoride tolerances because aggregate exposure to fluoride
poses a long litany of threats to health. According to the Objectors,
the NRC Report linked fluoride not just to adverse effects on bones and
teeth but also other effects ranging from neurological impacts to
cancer. (Ref. 2 at 11, 13-15). The weight of this argument, however, is
undermined by two factors.
First, it is beyond dispute that NRC, after a comprehensive
evaluation of all of the possible adverse effects of fluoride,
recommended that OW lower the fluoride MCLG due to only three very
specific health risks: severe dental fluorosis; stage II skeletal
fluorosis; and bone fractures. (Ref. 17 at 345-346, 352). Although the
NAS recommended further research on some of the other health risks
cited by the Objectors, the NAS did not find sufficient evidence on any
of them to support a lowering of the MCLG.
Second, and more importantly, the threat that fluoride poses to
teeth and bones is due to aggregate exposure to fluoride not the
fluoride in food resulting from use of sulfuryl fluoride when viewed in
isolation. Use of sulfuryl fluoride is responsible for a tiny fraction
of aggregate fluoride exposure. For example, for the most highly-
exposed age groups in the populations examined in the revised risk
assessment, fluoride from sulfuryl fluoride accounts for about 2 to 3%
of aggregate fluoride exposure. Given the aggregate level of fluoride
exposure, termination of the use of sulfuryl fluoride would not change
the fact that aggregate fluoride levels would still exceed the safe
level for highly-exposed subpopulations.
C. Harm to Others/Other Public Health Harms
1. Overview. Immediate termination of sulfuryl fluoride tolerances
will lead to some combination of the following negative consequences
depending how food processors and distributors for the various affected
commodities respond: an increase in the use of inventories of the
stratospheric ozone-depleting pesticide, methyl bromide; a disruption
in the amount and availability of certain commodities; an increase in
contamination of commodities with insect parts and waste posing
potential health risks; and/or increased short-term and long-term costs
for food processors, distributors, and consumers. To the extent that
methyl bromide cannot be obtained in sufficient quantities to fill the
void left by the absence of sulfuryl fluoride, the other potential
negative impacts will be heightened.
In the following discussion, EPA first describes the likely effects
that would occur in individual food markets if sulfuryl fluoride use is
terminated. Then EPA presents more general information on the
availability of methyl bromide, the potential disruption that can occur
when food is contaminated with insect parts and waste, and potential
health effects from such contamination.
2. Likely effects in specific markets. OPP analyzed three uses of
sulfuryl fluoride that provide a representative view of how the food
industries relying on sulfuryl fluoride may respond to a loss of that
pesticide and the impacts of that response:
Use of sulfuryl fluoride as a structural treatment in
flour mills;
Use of sulfuryl fluoride as a food fumigant for cocoa
beans; and
Use of sulfuryl fluoride as a food fumigant for walnuts.
Each of these uses is discussed in more detail in the next section.
(Refs. 25 and 26).
a. Flour mills. Generally, flour mills and other food processing
facilities are fumigated two to three times per year to control insect
populations (the primary pests are the red flour beetle and the
confused flour beetle). In the absence of sulfuryl fluoride, there are
potentially three possible alternative options whose costs and efficacy
differ from sulfuryl fluoride: (1) Use of another chemical pesticide;
(2) use of non-chemical controls; or (3) complete removal of all food
from the facility during fumigation with sulfuryl fluoride.
i. Chemical control. The only chemical alternative for use
throughout food processing facilities is methyl bromide. As explained
later in this document, mills and food processing
[[Page 3444]]
structures that do not have approved critical uses for a given year may
not obtain methyl bromide produced under a critical use exemption. To
the extent facilities have an approved critical use or can obtain
methyl bromide from pre-phase-out inventories, mills will likely switch
to methyl bromide if sulfuryl fluoride uses are immediately eliminated.
Costs for use of methyl bromide and sulfuryl fluoride appear to be
fairly similar at this time. No other chemical pesticides are a viable
alternative. Phosphine is a commonly-used food fumigant that could be
used in some portions of a flour mill; however, phosphine is highly
corrosive to silver and copper metals and their alloys and thus cannot
be used in the production areas of mills that contain electronic and
electrical equipment which heavily rely on these metals. In terms of
total area, the portion of a mill devoted to production is substantial
and a failure to effectively dis-infest the production area would
quickly result in re-infestation of the entire facility. Thus,
phosphine is not an alternative to the use of sulfuryl fluoride. (Ref.
25 at 6-7).
ii. Non-chemical control. The leading non-chemical control option
for use in flour mills is temperature manipulation. Either heat or cold
can be used to destroy insect pests. Use of cooling to control pests in
flour mills, however, is unlikely because cold temperatures can damage
electronic equipment in production areas. Use of heat is a more likely
option. Temperatures of 120-130 degrees Fahrenheit will kill most
stored-product insect pests. Heat, however, would not be appropriate
for mills principally constructed of wood because heat at these levels
will shrink, crack, and warp wood. This can result in structural damage
to the facility and may also render the heat treatment ineffective due
to leakage of heat from the facility. Approximately 25% of the total
number of flour mills in the United States fall in this category. These
tend to be the older and smaller mills and thus probably represent less
than 25% of mill capacity. Newer mills are generally constructed
primarily of concrete or similar materials which would be appropriate
for use with heat disinfestation techniques. Initially, use of heat
will involve higher costs due to capital investment in heaters and
plant modifications. However, in the long run, use of heat may be less
costly than chemical pesticides. Switching to heat will also require
transition time for the industry. Not only will mills have to purchase
(or rent) heaters but modifications may be necessary to the mill to
insure that heat is evenly distributed. Individual mills will have to
go through a trial and error process to determine how the heating
technique can be effective in each unique facility. Because
disinfestations are commonly needed only two to three times per year,
mills are likely to need an extended transition time to implement the
technology effectively. If chemical alternatives are not available
during that timeframe, processed food contaminated with insect parts
and waste due to failure of initial attempts at heat disinfestation
will have to be destroyed. (Ref. 25 at 6).
iii. Product removal. A third option that combines chemical and
non-chemical control would be complete removal of all food from a
facility before fumigation with sulfuryl fluoride. Currently, the
sulfuryl fluoride label requires that food in facilities be minimized
prior to fumigation. Only food that is not practical to remove may
remain during the fumigation. Removal of food is also essential to the
efficacy of sulfuryl fluoride. However, if all food is removed such
that use of sulfuryl fluoride would not result in fluoride residues in
food, no pesticide tolerance would be needed for this use and aggregate
exposure to fluoride would not be increased. Currently, Canada has
imposed restrictions on the use of sulfuryl fluoride for the fumigation
of food processing facilities that are designed to insure that no
residues result in food. Two obstacles remain, however, to adoption of
this alternative. First, OPP's analysis of this alternative indicates
there may be substantial costs. Second, at this time, sulfuryl
fluoride's FIFRA label does not contain application instructions
sufficient to eliminate residues on food. Thus, if the objections are
granted as is proposed, EPA will pursue cancellation of all uses
associated with the tolerances which are removed. Unless Dow
AgroSciences, the registrant for sulfuryl fluoride, were to seek an
amendment of its registration that imposes label restrictions insuring
no residues in food, and OPP can determine that the proposed
registration changes would achieve that result, this use would not be
available to flour mills in the United States. (Ref. 25 at 10).
b. Fumigation of cocoa and walnuts. Any food that is stored,
processed, or packaged is subject to attack by insects, generally
beetles or moths. Phosphine is the dominant fumigant in the commodity
market for use against such pests because it is efficacious, cost-
effective, and easy to apply. However, phosphine fumigation takes 4 to
7 days to be effective. A fumigant that can work much more quickly,
such as sulfuryl fluoride, is used when rapid fumigation is necessary.
Fumigation of harvested walnuts to destroy pests is primarily used
for in-shell walnuts. Fumigation can kill pests in in-shell walnuts
that are otherwise eliminated from shelled walnuts by shelling and
processing of the nutmeat. The available data indicate that a high
percentage of in-shell walnuts are fumigated one or more times.
Fumigation is primarily not conducted with phosphine because, at peak
harvest time, existing fumigation chambers do not have sufficient
capacity to allow timely fumigation. Although historically most of this
rapid fumigation was done with methyl bromide under a CUE, more recent
information suggests that the industry is using sulfuryl fluoride
almost entirely. (Ref. 26 at 4).
For cocoa beans, rapid fumigation is necessary due to the
circumstances where fumigation is conducted. Cocoa beans are imported
to the United States from Africa and South America. Upon arrival, they
are taken to a warehouse at the port and fumigated under tarpaulins. To
minimize risk to port employees, fumigations typically occur over
weekends when the ports and warehouses are closed. One hundred percent
of cocoa beans are fumigated with sulfuryl fluoride. (Id. at 5). In
2009, approximately $1.2 billion worth of cocoa beans were imported to
the United States.
The primary chemical alternative to sulfuryl fluoride for walnuts
and cocoa is phosphine. However, as indicated, there are insufficient
fumigation chambers for walnuts at peak harvest time. For cocoa,
existing facilities do not allow for use of phosphine because they are
part of an ongoing port operation and cannot be shut down for more than
2 days at a time and often contain other articles that may be affected
by phosphine's corrosive properties. Non-chemical alternatives either
take too long (cold, modified atmosphere), may damage the stored
commodity (heat), lack market acceptability (irradiation), or are
largely untested for the commodities and pests in question (heat).
Construction of fumigation chambers for walnuts and cocoa may take
several years. (Id. at 5).
EPA requests information on whether other commodities treated in
the United States or other imported commodities would be affected by
elimination of sulfuryl fluoride.
3. Availability of methyl bromide. Due to the constraints of CAA
and the Montreal Protocol, pesticide users would have very limited
ability to use methyl bromide in lieu of sulfuryl fluoride if the
sulfuryl fluoride
[[Page 3445]]
tolerances were abruptly withdrawn. Methyl bromide is an ozone
depleting substance whose production has been banned under the Clean
Air Act for domestic use since 2005. Along with other developed
countries, the United States is also subject to the methyl bromide
production phase-out under the Montreal Protocol. Production of methyl
bromide for U.S. use other than for quarantine and preshipment purposes
is not allowed under the Montreal Protocol and EPA's Clean Air Act
implementing regulations unless the Parties to the Montreal Protocol
agree to authorize additional new production for uses that have been
demonstrated to be critical under the criteria adopted by the Parties.
The criteria for critical use exemptions (CUEs) are demanding and
not easily met. Under Decision IX/6 of the Parties to the Montreal
Protocol ``a use of methyl bromide should qualify as `critical' only if
the nominating Party determines that: (i) The specific use is critical
because the lack of availability of methyl bromide for that use would
result in a significant market disruption; and (ii) there are no
technically and economically feasible alternatives or substitutes
available to the user that are acceptable from the standpoint of
environment and public health and are suitable to the crops and
circumstances of the nomination.'' Decision IX/6 para. 1(a).
Additionally, Decision IX/6 specifies that:
[P]roduction and consumption, if any, of methyl bromide for
critical uses should be permitted only if:
(i) All technically and economically feasible steps have been
taken to minimize the critical use and any associated emission of
methyl bromide;
(ii) Methyl bromide is not available in sufficient quantity and
quality from existing stocks of banked or recycled methyl bromide,
also bearing in mind the developing countries' need for methyl
bromide;
(iii) It is demonstrated that an appropriate effort is being
made to evaluate, commercialize and secure national regulatory
approval of alternatives and substitutes.* * *
Decision IX/6 para. 1(b).
EPA's stratospheric protection regulations contain essentially the
same criteria (40 CFR 82.3). Decisions on these criteria are made
following a careful review by both the United States and the Parties to
the Montreal Protocol.\1\ Importantly, because the CUE process is an
exception to the phase-out, it has been implemented in a manner that
recognizes the importance of the technical substantiation of critical
need relative to the criteria agreed upon by the Parties. Between the
2005 and 2011 CUE Nominations, the United States post harvest CUE
amount authorized by the Parties has declined by nearly 80% (784,936
kilograms (kg) to 161,394 kg). (Ref. 27). Given the potential
availability of alternatives in a few years, taking into consideration
the full suite of chemical and non-chemical pest control options for
post harvest uses, technical and economic substantiation for methyl
bromide would be limited under CUE criteria for uses that had
transitioned to sulfuryl fluoride.
---------------------------------------------------------------------------
\1\ Before U.S. production may legally occur, a specific use
must receive a CUE through the authorization of the Parties to the
Montreal Protocol and then through EPA's regulations. The CUE
process takes three years to complete for one control period (one
calendar year). Methyl bromide users who wished to obtain a CUE to
allow production in 2011 submitted their applications to EPA in
2008. The U.S. Government reviewed those applications and submitted
a Critical Use Nomination to the United Nations Environment
Programme Ozone Secretariat in early 2009. During 2009, the Methyl
Bromide Technical Options Committee (MBTOC) and the Technology and
Economic Assessment Panel (TEAP), which are independent advisory
bodies to the Parties to the Montreal Protocol, reviewed the
Critical Use Nomination and made recommendations to the Parties. In
the fall of 2009, the Parties met and approved CUEs for the
following post-harvest uses in the U.S.: mills and food processing
structures; country ham; dried fruit; and nuts. In 2010, EPA
initiated notice-and-comment rulemaking to exempt the approved uses
from its regulatory ban on methyl bromide production. The final rule
will address what uses qualify for the exemption in 2011 and what
amounts may be produced or imported for approved critical uses.
---------------------------------------------------------------------------
Finally, the ability of any given user group to use methyl bromide
will also be constrained in any given year by a number of other
factors. First, it is impermissible for any person to sell critical use
methyl bromide to an end user without receiving a certification that it
will be used for an approved critical use. (40 CFR 82.4(p)(1)(i)).
Second, although there is no legal restriction on a non-critical user
purchasing and using pre-phase-out stocks (the quantity of stored
methyl bromide produced prior to the U.S. phase-out in 2005), (75 FR
23167, 23181, May 3, 2010) (FRL-9144-5), whether or not such stocks
could be commercially obtained quickly given long-term contracting for
stocks is another question. In any event, pre-phase-out inventory has
declined substantially and it is unclear at this time how much of it
could be purchased for use in the post-harvest market.
Thus, in the short-term, production and import of methyl bromide is
restricted with no opportunities for immediate change. In the longer
term, given the historical trajectory of the critical use exemption
under the Montreal Protocol, there likely will be less, not more,
methyl bromide available. Current users of sulfuryl fluoride may
attempt to purchase methyl bromide from pre-phase-out inventories if
sulfuryl fluoride becomes unavailable; however, the feasibility of
obtaining significant quantities from this source is uncertain.
4. Disruption of the marketplace. Food containing insect parts and
waste may be considered adulterated under FFDCA section 402(a)(4) and
subject to seizure by FDA. (21 U.S.C. 342(a)(4); see 21 CFR 110.110
(Defect Action Levels)). As the recent recall of the infant formula
Similac shows, contamination with insect parts can result in extensive
disruption of the market for consumers and significant costs for the
food industry. (Ref. 28 (``Worried parents have bombarded the maker of
Similac with phone calls and peppered Facebook and Twitter pages over
fears about insects in the top-selling baby formula after millions of
cans were recalled.''); Refs. 29 and 30 (reporting that recall involved
``up to 5 million Similac-brand powder formulas'' and ``Abbot expects
to lose $100 million in connection with the recall.'')).
5. Harm to health. There is a real potential for adverse human
health impacts if sulfuryl fluoride is not available for treatment of
food commodities, food mills, and other food processing facilities
where sulfuryl fluoride is used. Without sulfuryl fluoride, there would
be re-infestation of those commodities or facilities if facilities are
not able to find suitable alternatives and thus more contamination of
food products by the pests controlled by sulfuryl fluoride.
Contamination would include whole insects, insect body parts, and
insect waste, mainly from various flour beetles, moths, and
cockroaches. Some of these contaminants (e.g., from cockroaches) have
been identified as allergens. (Ref. 31). Other beetles have been
associated with gastrointestinal illness and discomfort. (Ref. 32 and
33). Contamination also could include food-borne pathogens that cause
disease, such as E. coli or Salmonella, introduced by flies that would
no longer be controlled by sulfuryl fluoride. (Id.)
6. Conclusion. In the absence of sulfuryl fluoride tolerances,
current sulfuryl fluoride users will, in the first instance, turn to
methyl bromide if methyl bromide can be obtained. Users' ability to
obtain methyl bromide will depend on a complex mix of factors
including: when a final decision is made on the sulfuryl fluoride
tolerances; whether the use is an approved critical use for a given
year and, if so, the amount of methyl bromide available either from new
[[Page 3446]]
production or from pre-phase-out inventory under the CUE Rule for that
year; and whether users have access to pre-phase-out inventory sold for
non-critical exemption uses. To the extent that methyl bromide is used
as a sulfuryl fluoride replacement, such a reversion to a
stratospheric-ozone depleting chemical is a negative public health
impact because it will add to damage to the ozone layer and contribute
to additional health effects caused by exposure to ultraviolet
radiation, including skin cancers and cataracts.
If both sulfuryl fluoride and methyl bromide are unavailable, or
supplies are limited, there is likely to be some disruption of the food
supply as to the affected commodities and/or there is a greater
likelihood of contaminated food being released for public consumption.
The extent of disruption and/or contamination varies based on the type
of processing facility and the commodities involved. For newer flour
mills and other food processing facilities (i.e., ones made principally
of concrete), use of heat should eventually be a successful alternative
to sulfuryl fluoride. In the interim, food may become contaminated with
insect parts and waste as facility owners use trial and error in
adapting heat technology to their individual facilities.
Older processing facilities constructed mainly of wood may have no
options other than to cease production unless Dow AgroSciences seeks
and obtains a registration amendment for sulfuryl fluoride that insures
that sulfuryl fluoride is used in a manner not resulting in residues in
food. Even so, it is unknown whether use of sulfuryl fluoride under
such an approach is economically feasible. EPA expects similar impacts
on other food handling facilities that rely on sulfuryl fluoride or
methyl bromide fumigation to control pests.
As to cocoa, impacts are likely to be very substantial. Currently,
100% of the imported cocoa in the United States is disinfested using
sulfuryl fluoride. The likelihood of switching to methyl bromide is
quite low. As of June 29, 2007 for the 2009 CUE control period, cocoa
bean users of methyl bromide ceased seeking CUEs. Cocoa is not
currently an approved critical use, and thus any methyl bromide
produced under a CUE cannot be used on cocoa. Cocoa importers' only
avenue for using methyl bromide would be to purchase methyl bromide
from the dwindling pre-phase-out inventories. Eventually, fumigation
chambers for phosphine could be constructed for cocoa but it may be a
matter of years before they are operational and phosphine use is not
feasible at existing sulfuryl fluoride fumigation sites. In the absence
of an alternative to sulfuryl fluoride for disinfestation of cocoa,
cocoa imports (which in 2009 were valued at approximately $1.2 billion)
would be lost due to either destruction or refusal of shipments by
warehouse operators to comply with FDA regulations. Walnuts may also
face significant impacts because of the need for rapid fumigation with
either methyl bromide or sulfuryl fluoride. Without sulfuryl fluoride
or methyl bromide, a significant portion of the crop may be lost simply
due to insufficient fumigation capacity given the relatively long time
needed for fumigation with phosphine. Other commodities facing a
similar situation to walnuts include dried fruits other than raisins.
D. The Public Interest
Determining where the public interest lies in this matter involves
a complex weighing of inter-related environmental and health impacts
and cost effects upon commercial interests and consumers. OPP attempts
to capture each of these impacts in the following summary, some of
which have been described previously. Others are discussed for the
first time because they do not neatly fit under factors discussed
previously.
1. Harm from fluoride exposure. Aggregate exposure to fluoride
exceeds the safe level for several major identifiable population
subgroups. Of principal concern here are children up to the age of 7.
2. Sulfuryl fluoride's contribution to fluoride exposure. Use of
sulfuryl fluoride results in a minimal contribution to fluoride
exposure. Elimination of sulfuryl fluoride does not solve, or even
significantly decrease, the fluoride aggregate exposure problems
identified earlier.
3. Increase in the use of methyl bromide inventories. There is a
worldwide consensus that the use of chemicals that deplete the
stratospheric ozone, such as methyl bromide, should be eliminated.
Termination of sulfuryl fluoride will increase demand for methyl
bromide and may result in an increase of use of methyl bromide
inventories.
4. Impacts on the food supply. To the extent that neither methyl
bromide nor sulfuryl fluoride is available, there are likely to be
impacts on the food supply, either through disruption of food
availability or contamination of food with insect parts and waste,
because other feasible alternatives to sulfuryl fluoride and methyl
bromide will not be immediately available.
5. Other atmospheric effects of sulfuryl fluoride. EPA acknowledges
that recent research has identified the potential for sulfuryl fluoride
to contribute to the greenhouse effect; however there does not appear
to be consensus yet in the scientific community on its global warming
potential.
6. International consequences. As explained previously, the United
States agreed to end domestic production of methyl bromide in 2005,
along with other developed countries that are Parties to the Montreal
Protocol. Since 2005, the United States has--along with a handful of
other developed countries--been requesting limited continued amounts of
methyl bromide to satisfy needs that Parties agree to be `critical'.
Also since 2005, U.S. requests for continued uses have been large,
relative to those of other countries. At the beginning of the post-
phase-out period, in 2005, 17 developed countries requested and
obtained such exemptions; currently, the United States is one of only
four developed countries that have not yet eliminated methyl bromide
CUEs. (Ref. 27). The United States historically used a majority of the
world's methyl bromide; therefore, the challenge faced by U.S.
agriculture in this transition has been formidable. Still, enormous
progress has been made in adopting alternatives for all major uses,
allowing the United States to substantially reduce the size and number
of its CUE requests. Sulfuryl fluoride has been an important component
to this process. A sudden reversal by the United States in its efforts
to reduce the use of methyl bromide may have broad ramifications on the
success of the treaty. U.S. authorizations have been reduced further by
the Parties to the Montreal Protocol, based on recommendations from the
relevant technical committees of the Montreal Protocol. Rapid
termination of sulfuryl fluoride tolerances would be at odds with the
careful, deliberate, and well-established CUE process. The process is
protracted and the relevant criteria demand technical justifications
that require time to develop and substantiate. In reality, the multi-
step CUE process is not designed with the expectation that it would
allow a Party to the Montreal Protocol requesting a CUE for a given
year to rapidly adjust either to the introduction of a new alternative
or to the withdrawal of an existing alternative. An additional
international consequence is that the lack of sulfuryl fluoride to
treat imported commodities
[[Page 3447]]
such as cocoa could lead to shipments of imported commodities being
rejected and trade with some economically vulnerable countries may be
negatively affected.
E. Conclusion
Taking all of these factors into account involves weighing EPA's
proposed conclusion that Objectors' have meritorious objections and the
potential beneficial impacts on the public interest if a stay was
granted against the negative impacts on the public interest from a stay
approval. The beneficial impacts from granting a stay would be a slight
reduction in fluoride exposure and other potential atmospheric effects.
On the other hand, granting a stay would potentially cause the
following negative impacts:
1. A possible increase in use of methyl bromide inventories, with
attendant negative known atmospheric effects;
2. An undermining of the substantial progress made in reducing
methyl bromide critical use exemptions in the postharvest market and
potential disruption in implementation of an important international
treaty, and
3. Significant impacts on several food industries and related
effects on the public, including potential health effects on the
public.
Despite the health risks posed by overall aggregate fluoride exposure
and the Objectors' likelihood of success on the merits, OPP believes
that each of the potential negative impacts on the public interest
outweigh the beneficial public effects from a stay. Viewed in this
light, EPA concludes that the public interest strongly, in fact
overwhelmingly, supports denial of the Objectors' stay request.
VIII. Proposed Effective Date of Order
EPA proposes to make this order effective 60 days following
publication. However, EPA is also proposing a staggered implementation
for withdrawal of the affected tolerances in 40 CFR 180.145(c) and
180.575 taking into account the discussion in Unit VII. concerning the
Objectors' stay request. This staggered implementation is proposed to
be accomplished by including an expiration/revocation date in 40 CFR
180.145(c) and 180.575 for each of the tolerances not proposed for
withdrawal upon the effective date of the order. Given the potential
disruption or contamination of some commodities in the food supply,
severely limited availability of methyl bromide, and prospect of
difficulties in implementing an important international treaty, EPA is
proposing to withdraw tolerances under the following implementation or
phaseout schedule:
1. Tolerances for canceled uses: immediately. For uses that have
been removed from the sulfuryl fluoride registration, there is no
reason the proposed order should not take effect upon the effective
date of the order. These tolerances are: Dried eggs; milk, powdered.
2. Tolerances for commodities where there is little to no use of
sulfuryl fluoride: 90 days. EPA's analysis and information from Dow
AgroSciences indicate that sulfuryl fluoride is not currently used in
significant amounts, if at all, on numerous commodities for which
direct fumigation is allowed under the sulfuryl fluoride registration.
EPA is proposing a termination of tolerances associated with these uses
90 days from the effective date of the order. Ninety days should be
sufficient for all affected parties to come into compliance with the
revised situation. Tolerances in this category are: barley, bran,
postharvest; barley, flour, postharvest; barley, grain, postharvest;
barley, pearled barley, postharvest; cattle, meat, dried; cheese;
coconut, postharvest; coffee, bean, green, postharvest; corn, field,
flour, postharvest; corn, field, grain, postharvest; corn, field,
grits, postharvest; corn, field, meal, postharvest; corn, pop, grain,
postharvest; cotton, undelinted seed, postharvest; ginger, postharvest;
grain, aspirated fractions, postharvest; grape, raisin, postharvest;
herbs and spices group 19, postharvest; hog, meat; millet, grain,
postharvest; nut, pine, postharvest; nut, tree, Group 14, postharvest
(revised to cover only walnuts, postharvest); oat, flour, postharvest;
oat, grain, postharvest; oat, groat/rolled oats; peanut, postharvest;
pistachio, postharvest; sorghum, grain, postharvest; triticale, grain,
postharvest; vegetable, legume, group 6, postharvest; wheat, bran,
postharvest; wheat, flour, postharvest; wheat, germ, postharvest;
wheat, grain postharvest; wheat, milled byproducts, postharvest; wheat,
shorts, postharvest.
3. Tolerances for commodities directly treated where there is
significant sulfuryl fluoride use and no readily-available alternative:
3 years. For several commodities, sulfuryl fluoride is used on all, or
a substantial portion, of the crop and there is no readily-available
alternative. These commodities are cocoa, walnuts, and dried fruits
other than raisins. Although there is a feasible alternative available
for sulfuryl fluoride in the long-term, phosphine, in the short-term
that alternative is not available due to the lack of fumigation
capacity. The situation for cocoa is perhaps the most dire in that 100%
of the crop is treated, the space used for sulfuryl fluoride fumigation
is not appropriate for phosphine use, and, given that cocoa is not
currently an approved critical use, methyl bromide produced under a CUE
may not be used on cocoa. While not facing quite such catastrophic
consequences, walnuts are nonetheless in essentially the same situation
because the only realistic treatment option in the near term (i.e.,
methyl bromide) can only be obtained, if at all, from pre-phase-out
inventories or from production under the sharply-limited postharvest
CUE, and another alternative will not be available until additional
fumigation capacity is created. The situation appears similar for dried
fruits other than raisins as well; however, EPA requests that
information be submitted during the comment period documenting the
amount of sulfuryl fluoride use on dried fruits and the availability of
alternatives including the availability of capacity for alternative
fumigations. EPA is proposing termination of tolerances associated with
these uses 3 years from the effective date of the order. Construction
of fumigation chambers may take several years.
4. Tolerances for commodities receiving residues from incidental
treatment during structural fumigation--3 years. The situation for
foods requiring tolerances as a result of incidental treatment from
structural fumigations is more complicated. Different types of
facilities will face different hurdles in transitioning from sulfuryl
fluoride to other methods of pest control. For most facilities, use of
heat may prove an adequate pest control strategy. However,
implementation of heat technology is not expected to be seamless and
the availability of sulfuryl fluoride as a backup to avoid potential
disruption or contamination is important. OPP expects that, after the
first year, use of sulfuryl fluoride in these facilities will be the
exception rather than the rule as the technology comes online and
facility operators gain experience with it. In other words, sulfuryl
fluoride would only be used when difficulties arise in perfecting the
use of heat technology in individual facilities. Given the cost of
sulfuryl fluoride treatment, facility operators, having invested in
heat technology, will have a strong incentive to avoid use of sulfuryl
fluoride unless absolutely necessary. A relatively short transition
period may be appropriate for these facilities. For wooden structures,
however, where heat is not an option,
[[Page 3448]]
no chemical or non-chemical alternative is immediately available. These
facilities face an uncertain future with perhaps the best alternative
being pursuit by Dow AgroSciences of restrictions on the sulfuryl
fluoride registration that would eliminate the possibility of residues
in food and thus permit continued use of sulfuryl fluoride as a
structural fumigant in food handling facilities. Nonetheless, even this
approach is in question due to feasibility issues. Thus, to some
degree, owners of wooden food handling facilities face the most serious
consequences of any producer group and, due to their relatively large
share of the market, there could be similarly serious consequences for
the public. For that reason, EPA is proposing termination of tolerances
associated with these uses 3 years from the effective date of the
order. To insure that this extended transition period will not
encourage owners of concrete facilities to maintain the status quo, EPA
plans to pursue registration modifications for sulfuryl fluoride that
differentiate between sulfuryl fluoride use in concrete and wooden
structures. EPA's goal would be to allow sulfuryl fluoride use in
concrete facilities for a period no longer than necessary to accomplish
the transition to heat technology.
EPA specifically requests comment on the potential impacts from the
loss of sulfuryl fluoride including any available and additional
information on pest control alternatives to sulfuryl fluoride. Such
information is important to EPA's decision on the proposed effective
dates for this order. Further, EPA recognizes that sulfuryl fluoride is
only one of many sources of exposure to fluoride. To the extent that
new information indicates that overall fluoride exposure has decreased,
including as a result of other government actions, EPA would consider
revisiting the determinations in this proposed order.
IX. Request for Public Comment
EPA requests public comment on all aspects of this proposed order:
Its hazard, exposure, and risk assessments of fluoride; its evaluation
of the factors bearing on whether a stay should be granted; and its
proposed effective dates for the order.
X. Regulatory Assessment Requirements
As indicated previously, this action announces the Agency's
proposed order regarding objections filed under section 408 of FFDCA.
As such, this action is an adjudication and not a rule. The regulatory
assessment requirements imposed on rulemaking do not, therefore, apply
to this action.
XI. Submission to Congress and the Comptroller General
The Congressional Review Act, (5 U.S.C. 801 et seq.), as added by
the Small Business Regulatory Enforcement Fairness Act of 1996, does
not apply to this order because this action is not a rule for purposes
of 5 U.S.C. 804(3).
XII. References
As indicated under ADDRESSES, a docket has been established for
this rulemaking under docket ID number EPA-HQ-OPP-2005-0174. The
following is a listing of the documents that are specifically
referenced in this document. The docket includes these documents and
other information considered, including documents that are referenced
within the documents that are included in the docket, even if the
referenced document is not physically located in the docket. For
assistance in locating these other documents, please consult the
technical contact listed under FOR FURTHER INFORMATION CONTACT.
1. Fluoride Action Network and Beyond Pesticides/National
Coalition Against the Misuse of Pesticides, Written Objections and
Request for Hearing in the matter of: Sulfuryl Fluoride; Pesticide
Tolerance; Final Rule. (March 23, 2004).
2. Motion of Objectors for Stay of Final Rules Establishing
Tolerances For Residues of Sulfuryl Fluoride and Fluoride Anion;
(Docket Nos. OPP-2005-0174 and OPP-2003-0373) (June 1, 2006).
3. Objectors' Consolidated Objections to Final Rules
Establishing Tolerances for Residues of Sulfuryl Fluoride and
Fluoride Anion (November 6, 2006).
4. USEPA, A User's Guide to Available EPA Information on
Assessing Exposure to Pesticides in Food (June 21, 2000).
5. USEPA. Office of Research and Development. 2000. Benchmark
Dose Technical Guidance Document. Draft report. Risk Assessment
Forum, Office of Research and Development, U.S. Environmental
Protection Agency. Washington, DC. EPA/630/R-00/001.
6. FIFRA Science Advisory Panel. 2002. Methods Used to Conduct a
Preliminary Cumulative Risk Assessment for Organophosphate
Pesticides. Final Report from the FIFRA Scientific Advisory Panel
Meeting of February 5-7, 2002 (Report dated March 19, 2002). FIFRA
Scientific Advisory Panel, Office of Science Coordination and
Policy, Office of Prevention, Pesticides and Toxic Substances, U.S.
Environmental Protection Agency. Washington, DC. SAP Report 2002-01.
7. FIFRA Science Advisory Panel. 2005b. Final report on
Preliminary N-Methyl Carbamate Cumulative Risk Assessment. Final
Report from the FIFRA Scientific Advisory Panel Meeting of August
23-25, 2005 (Report dated October 13, 2005). Available at: http://www.epa.gov/scipoly/sap/2005/august/minutes.pdf.
8. Office of Pesticide Programs, USEPA, Office of Pesticide
Programs' Policy on the Determination of the Appropriate FQPA Safety
Factor(s) For Use in the Tolerance Setting Process (February 28,
2002).
9. USEPA, Residue Chemistry Test Guidelines: OPPTS 860.1500 Crop
Field Trials (August 1996).
10. Office of Pesticide Programs, USEPA and Pest Regulatory
Management Agency, Health Canada, NAFTA Guidance Document for
Guidance for Setting Pesticide Tolerances Based on Field Trial Data
(September 28, 2005).
11. Office of Pesticide Programs, USEPA, Choosing a Percentile
of Acute Dietary Exposure as a Threshold of Regulatory Concern
(March 16, 2000).
12. Office of Pesticide Programs, USEPA, Standard Operating
Procedures (SOPs) for Residential Exposure Assessments (Draft
December 19, 1997).
13. Office of Prevention, Pesticides, and Toxic Substances,
USEPA, ``Response To Public Comments Concerning The Use Of Sulfuryl
Fluoride As A Post-Harvest Fumigant'' (January 16, 2004).
14. Baetcke et al., Office of Pesticide Programs, USEPA, ``A
Preliminary Evaluation of Articles Related to Fluoride Cited by the
Fluoride Action Network (FAN) as Objections to the Sulfuryl Fluoride
Pesticide Tolerance Rule'' (November 18, 2003).
15. Office of Prevention, Pesticides, and Toxic Substances,
USEPA, Memorandum from Vicki L. Dellarco to Dennis McNeilly, Review
of Five Recent Papers on Fluoride Submitted by the Fluoride Action
Network (January 8, 2004).
16. Office of Prevention, Pesticides, and Toxic Substances,
USEPA, ``Response to Public Comments Concerning the Use of Sulfuryl
Fluoride In Food Handling Facilities'' (July 14, 2005).
17. National Research Council of the National Academies,
``Fluoride in Drinking Water: A Scientific Review of EPA's
Standards'' (March 2006).
18. Objectors' Submission to Docket: 18 IQ Studies (posted
February 17, 2009).
19. Dow AgroSciences LLC, ``Response to Request for Public
Comments; Sulfuryl Fluoride; Request for Stay of Tolerances; Public
Docket Identification Numbers: EPA-HQ-OPP-2005-0174 and EPA-HQ-OPP-
2003-0373 (August 4, 2006).
20. Dow AgroSciences LLC, Memorandum, ``Standard for Granting a
Hearing under the Federal Food, Drug, and Cosmetic Act Concerning
Objections to Tolerances Established by EPA for Profume \TM\ Gas
Fumigant'' (October 31, 2006).
21. Health and Ecological Criteria Division, Office of Water,
USEPA, ``Fluoride: Dose-Response Analysis for Non-cancer Effects''
(December 2010).
22. Health and Ecological Criteria Division, Office of Water,
USEPA, ``Fluoride: Exposure and Relative Source Contribution
Analysis'' (December 2010).
23. Office of Chemical Safety and Pollution Prevention, US EPA,
Memorandum from Michael A. Doherty to Meredith Laws, ``Sulfuryl
Fluoride--Revised Human Health
[[Page 3449]]
Risk Assessment for Fluoride to Incorporate New Hazard and Exposure
Information'' (January 7, 2011).
24. Office of Prevention, Pesticides, and Toxic Substances, US
EPA, Memorandum from Colwell A. Cook, Jonathan Becker, and Elisa Rim
to Kable Davis/Venus Eagle and Michael Doherty/Christina Swartz,
``Revised Assessment of Percent Commodity Treated Values used in the
Registrant's Dietary Exposure Assessment for Fluoride (DP
361041)'' (May 1, 2009).
25. Office of Chemical Safety and Pollution Prevention, US EPA,
Memorandum from Michelle Ranville and Colwell Cook to Meredith Laws,
``Assessment of Impacts on Flour Mills Operators of a Stay in
Sulfuryl Fluoride Food Tolerances'' (January 7, 2011).
26. Office of Chemical Safety and Pollution Prevention, US EPA,
Memorandum from Colwell Cook and Michelle Ranville to Meredith Laws,
``Assessment of Impacts of a Stay of Food Tolerances for Sulfuryl
Fluoride on Selected Post-Harvest Commodities'' (January 7, 2011).
27. Office of Chemical Safety and Pollution Prevention, US EPA,
Memorandum from Colwell Cook and Michelle Ranville to Jonathan
Fleuchaus, Post Harvest Methyl Bromide Grant to the United States by
the Parties to the Montreal Protocol, 2005-2011 (December 16, 2010).
28. Washington Post, ``Bugs in Baby Formula? Parents Worried
About Recall'' (September 24, 2010) (available at http://www.washingtonpost.com/wp-dyn/content/article/2010/09/24/AR2010092402044.html?waporef=obinsite).
29. U.S. FDA Consumer Update, ``Abbott Recalls Some Similac
Formulas (September 23, 2010) (available at http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm226941.htm).
30. Washington Post, ``Bug Contamination Sparks Baby Formula
Recall'' (September 23, 2010) (available at http://www.washingtonpost.com/wp-dyn/content/article/2010/09/22/AR2010092206070.html?waporef=obinsite).
31. Olsen et al., Regulatory Action Criteria for Filth and Other
Extraneous Materials, V. Strategy for Evaluating Hazardous and
Nonhazardous Filth (Jan. 12, 2001).
32. U.S. FDA Consumer Update, ``Abbott Recalls Some Similac
Formulas'' (September 23, 2010) (available at http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm226941.htm).
33. Olsen, Alan, FDA Teamwork Uncovers Insect Infestation, FDA
Consumer, Vol. 25, Jul.-Aug. 1991).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: January 7, 2011.
Steve Bradbury,
Director, Office of Pesticide Programs.
[FR Doc. 2011-917 Filed 1-18-11; 8:45 am]
BILLING CODE 6560-50-P