[Federal Register Volume 64, Number 2 (Tuesday, January 5, 1999)]
[Proposed Rules]
[Pages 688-729]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34835]
[[Page 687]]
_______________________________________________________________________
Part VI
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 372
Persistent Bioaccumulative Toxic (PBT) Chemicals; Proposed Rule
Federal Register / Vol. 64, No. 2 / Tuesday, January 5, 1999 /
Proposed Rules
[[Page 688]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 372
[OPPTS-400132; FRL-6032-3]
RIN 2070-AD09
Persistent Bioaccumulative Toxic (PBT) Chemicals; Lowering of
Reporting Thresholds for Certain PBT Chemicals; Addition of Certain PBT
Chemicals; Amendments to Proposed Addition of a Dioxin and Dioxin-Like
Compounds Category; Toxic Chemical Release Reporting; Community Right-
to-Know
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: EPA is proposing to lower the reporting thresholds for certain
persistent bioaccumulative toxic chemicals that are subject to
reporting under section 313 of the Emergency Planning and Community
Right-to-Know Act of 1986 (EPCRA) and section 6607 of the Pollution
Prevention Act of 1990 (PPA). EPA is also proposing lower reporting
thresholds for dioxin and dioxin-like compounds, which were previously
proposed for addition to the EPCRA section 313 list of toxic chemicals.
EPA is proposing these actions pursuant to its authority under EPCRA
section 313(f)(2) to revise reporting thresholds. In addition, EPA is
proposing to add certain persistent and bioaccumulative toxic chemicals
to the list of chemicals subject to the reporting under EPCRA section
313 and PPA section 6607 and to establish lower reporting thresholds
for these chemicals. EPA is proposing to add these chemicals to the
EPCRA section 313 list pursuant to its authority to add chemicals and
chemical categories that meet the EPCRA section 313(d)(2) toxicity
criteria. The proposed additions of these chemicals are based on their
carcinogenicity or other chronic human health effects and/or their
adverse effects on the environment. As part of today's actions, EPA is
amending its proposal published in the Federal Register of May 7, 1997,
to add a category of dioxin and dioxin-like compounds to the EPCRA
section 313 list of toxic chemicals by proposing to exclude the co-
planar polychlorinated biphenyls (PCBs) from the category and by
proposing to add an activity qualifier to the category. EPA is also
proposing to require that separate reports be filed for tetraethyl lead
and tetramethyl lead which are listed under the lead compounds
category. Today's actions also include proposed modifications to
certain reporting exemptions and requirements for those toxic chemicals
that would be subject to the lower reporting thresholds.
DATES: Written comments, identified by the docket control number OPPTS-
400132, must be received by EPA on or before March 8, 1999.
ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I. of the SUPPLEMENTARY INFORMATION section of this
proposal.
FOR FURTHER INFORMATION CONTACT: Daniel R. Bushman, Petitions
Coordinator, 202-260-3882, e-mail: [email protected], for
specific information on this proposed rule, or for more information on
EPCRA section 313, the Emergency Planning and Community Right-to-Know
Hotline, Environmental Protection Agency, Mail Code 5101, 401 M St.,
SW., Washington, DC 20460, Toll free: 1-800-535-0202, in Virginia and
Alaska: 703-412-9877 or Toll free TDD: 1-800-553-7672.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does This Action Apply To Me?
You may be potentially affected by this action if you manufacture,
process, or otherwise use any of the chemicals listed under Table 1 in
Unit V.C.1. of this preamble. Potentially affected categories and
entities may include, but are not limited to:
------------------------------------------------------------------------
Examples of Potentially
Category Affected Entities
------------------------------------------------------------------------
Industry Facilities that: incinerate or
otherwise treat, store or
dispose of hazardous waste or
sewage sludge; operate chlor-
alkali processes; manufacture
chlorinated organic compounds,
pesticides, other organic or
inorganic chemicals, tires,
inner tubes, other rubber
products, plastics and
material resins, paints,
Portland cement, pulp and
paper, asphalt coatings, or
electrical components; operate
cement kilns; operate
metallurgical processes such
as steel production, smelting,
metal recovery furnaces, blast
furnaces, coke ovens, metal
casting and stamping; operate
petroleum bulk terminals;
operate petroleum refineries;
operate industrial boilers
that burn coal, wood,
petroleum products; and
electric utilities that
combust coal and/or oil for
distribution of electricity in
commerce
------------------------------------------------------------------------
Federal Government Federal facilities that: burn
coal, wood, petroleum
products; burn wastes;
incinerate or otherwise treat,
store or dispose of hazardous
waste or sewage sludge.
------------------------------------------------------------------------
This table 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 the table could also be
affected. To determine whether your facility would be affected by this
action, you should carefully examine the applicability criteria in part
372 subpart B of Title 40 of the Code of Federal Regulations. If you
have questions regarding the applicability of this action to a
particular entity, consult the person listed in the preceding ``FOR
FURTHER INFORMATION CONTACT'' section.
B. How Can I Get Additional Information or Copies of this Document or
Other Support Documents?
1. Electronically. You may obtain electronic copies of this
document and various support documents from the EPA internet Home Page
at http://www.epa.gov/. On the Home Page select
[[Page 689]]
``Laws and Regulations'' and then look up the entry for this document
under the ``Federal Register - Environmental Documents.'' You can also
go directly to the ``Federal Register'' listings at http://www.epa.gov/
fedrgstr/.
2. In person or by phone. If you have any questions or need
additional information about this action, please contact the technical
person identified in the ``FOR FURTHER INFORMATION CONTACT'' section.
In addition, the official record for this notice, including the public
version, has been established under docket control number OPPTS-400132,
(including the references in Unit XI. of this preamble and comments and
data submitted electronically as described below). This record includes
not only the documents physically contained in the docket, but all of
the documents included as references in those documents. A public
version of this record, including printed, paper versions of any
electronic comments, which does not include any information claimed as
Confidential Business Information (CBI), is available for inspection
from noon to 4 p.m., Monday through Friday, excluding legal holidays.
The public record is located in the TSCA Nonconfidential Information
Center, Rm. NE-B607, 401 M St., SW., Washington, DC 20460. The TSCA
Nonconfidential Information Center telephone number is 202-260-7099.
C. How and to Whom Do I Submit Comments?
You may submit comments through the mail, in person, or
electronically. Be sure to identify the appropriate docket number
(i.e., ``OPPTS-400132'') in your correspondence.
1. By mail. Submit written comments to: Document Control Office
(7407), Office of Pollution Prevention and Toxics (OPPT), Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460.
2. In person or by courier. Deliver written comments to: Document
Control Office in Rm. G-099, Waterside Mall, 401 M St., SW.,
Washington, DC, telephone: 202-260-7093.
3. Electronically. Submit your comments and/or data electronically
by E-mail to: ``[email protected].'' Please note that you
should not submit any information electronically that you consider to
be CBI. Electronic comments must be submitted as an ASCII file avoiding
the use of special characters and any form of encryption. Comments and
data will also be accepted on standard computer disks in WordPerfect
5.1/6.1 or ASCII file format. All comments and data in electronic form
must be identified by the docket control number OPPTS-400132.
Electronic comments on this notice may also be filed online at many
Federal Depository Libraries.
D. How Should I Handle CBI Information that I Want to Submit to the
Agency?
You may claim information that you submit in response to this
document as CBI by marking any part or all of that information as CBI.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. A copy of the comment that does
not contain CBI must be submitted for inclusion in the public record.
Information not marked confidential will be included in the public
docket by EPA without prior notice. If you have any questions about CBI
or the procedures for claiming CBI, please consult with the technical
person identified in the ``FOR FURTHER INFORMATION CONTACT'' section.
II. Statutory Authority
These actions are proposed under sections 313(d)(1) and (2),
313(f)(2), and 328 of EPCRA, 42 U.S.C. 11023(d)(1)-(2), 11023(f)(2),
and 11048.
Section 313 of EPCRA requires certain facilities manufacturing,
processing, or otherwise using a listed toxic chemical in amounts above
reporting threshold levels, to report their environmental releases of
each chemical annually. These reports must be filed by July 1 of each
year for the previous calendar year. Facilities also must report
pollution prevention and recycling data for such chemicals, pursuant to
section 6607 of PPA.
A. Addition of Chemicals
Section 313 established an initial list of toxic chemicals that was
comprised of more than 300 chemicals and 20 chemical categories.
Section 313(d) authorizes EPA to add or delete chemicals from the list,
and sets forth criteria for these actions. EPA has added and deleted
chemicals from the original statutory list. Under section 313(e)(1),
any person may petition EPA to add chemicals to or delete chemicals
from the list. Pursuant to EPCRA section 313(e)(1), EPA must respond to
petitions within 180 days, either by initiating a rulemaking or by
publishing an explanation of why the petition is denied.
EPCRA section 313(d)(2) states that a chemical may be added to the
list if any of the three listing criteria set forth there are met.
Therefore, in order to add a chemical, EPA must find that at least one
criterion is met, but does not need to examine whether all other
criteria are also met. EPA has published a statement elaborating its
interpretation of the section 313(d)(2) and (3) criteria for adding and
deleting chemicals from the section 313 list (59 FR 61432, November 30,
1994) (FRL-4922-2).
As discussed in Unit IV. of this preamble, EPA conducted a hazard
assessment on each chemical being proposed for addition to the EPCRA
section 313 list of toxic chemicals. This assessment was separate and
independent from the review conducted to determine each chemical's
persistence and bioaccumulation potential, although EPA considered some
of the same data in certain of its hazard assessments. EPA found that
each chemical being proposed for addition meets the criteria for
chronic human toxicity and/or environmental toxicity, as set forth at
EPCRA section 313(d)(2)(B)-(C).
B. Lowering of Reporting Thresholds
Section 313 contains default reporting thresholds, which are set
forth in section 313(f)(1). Section 313(f)(2), however, provides that
EPA ``may establish a threshold amount for a toxic chemical different
from the amount established by paragraph (1).'' The amounts established
by EPA may, at the Administrator's discretion, be based on classes of
chemicals or categories of facilities.
This provision provides EPA with broad authority to establish
thresholds for particular chemicals, classes of chemicals, or
categories of facilities, and commits to EPA's discretion the
determination that a different threshold is warranted. Congress has
also committed the determination of the levels at which to establish an
alternate threshold to EPA's discretion, requiring only that any
``revised threshold shall obtain reporting on a substantial majority of
total releases of the chemical at all facilities subject to the
requirements'' of section 313. 42 U.S.C. 11023(f)(2). For purposes of
determining what constitutes a ``substantial majority of total
releases'', EPA interprets ``facilities subject to the requirements''
of section 313 as the facilities currently reporting, in part because
section 313(b)(1)(A) provides that ``the requirements of [section 313]
shall apply'' to facilities that meet all the reporting criteria and
hence are required to file reports. Thus, in revising the reporting
thresholds, EPA must ensure that under the new thresholds a substantial
majority of releases currently being reported will continue to be
reported. No further guidance for exercising this authority appears in
the statute.
[[Page 690]]
While the ``substantial majority'' requirement of section 313(f)(2)
applies whether EPA is raising or lowering thresholds, EPA believes
that as a practical matter this standard can operate to constrain EPA's
action only when the Agency is raising the thresholds and thereby
reducing reporting. Under those circumstances the releases reported
under the new threshold would be lower than those being reported under
the current threshold, and EPA would be required to determine that the
reduction in reporting would not be so great as to fail the
``substantial majority'' test. When EPA lowers thresholds, however, the
substantial majority test is met as a matter of logical necessity,
because the lower thresholds are almost always likely to result in
increased, rather than decreased, reporting. The required findings
therefore can be made without the need for quantitative support. Thus,
EPA has found that the revised reporting thresholds contained in
today's proposed action meet the ``substantial majority'' test in
section 313(f)(2).
Because Congress provided no prerequisites to the exercise of EPA's
authority to lower the thresholds, and little explicit guidance, EPA
looked to the purposes of section 313 to help guide the exercise of its
discretion. EPCRA section 313(h) indicates that the data collected
under EPCRA section 313 are intended
to inform persons about the releases of toxic chemicals to the
environment; to assist governmental agencies, researchers, and other
persons in the conduct of research and data gathering; to aid in the
development of appropriate regulations, guidelines and standards,
and for other similar purposes. (42 U.S.C. 11023(h)).
As EPA has previously articulated in another rulemaking, EPA has
identified several purposes of the EPCRA section 313 program, as
envisioned by Congress, including: (1) Providing a complete profile of
toxic chemical releases and other waste management activities; (2)
compiling a broad-based national data base for determining the success
of environmental regulations; and (3) ensuring that the public has easy
access to these data on releases of toxic chemicals to the environment.
See 62 FR 23834, 23836 (May 1, 1997). EPA considered these purposes in
exercising its discretion to establish lower reporting thresholds under
EPCRA section 313 for persistent, bioaccumulative chemicals.
C. Modifications to Other EPCRA section 313 Reporting Requirements
Congress granted EPA extremely broad rulemaking authority to allow
the Agency to fully implement the statute. EPCRA section 328 provides
that the ``Administrator may prescribe such regulations as may be
necessary to carry out this chapter'' (28 U.S.C. 11048).
III. Explanation for Lowering Reporting Thresholds
A. General Background
In 1986, Congress passed EPCRA. This new law recognized the unique
role that communities can play in assuring environmental protection at
the local level. Just prior to the passage of EPCRA, fatal chemical
releases from a chemical manufacturing facility in Bhopal, India
highlighted the need for developing and sharing both emergency planning
information and routine release information with the public. The
identification of United States facilities, chemicals, and processes
identical to the Bhopal situation brought home the potential for
similar accidents in the United States as well as a recognition that
routine releases of toxic chemicals associated with routine facility
processes could pose significant risks to communities. These routine,
annual releases, if assessed at all, were known only to the facilities
themselves. Communities however, were unaware of the magnitude and
potential consequences of such releases.
Section 313 of EPCRA resulted in the creation of the Toxics Release
Inventory (TRI). TRI is a publicly available data base that provides
quantitative information on toxic chemical releases and other waste
management activities. With the collection of this information for the
first time in 1987, came the ability for the public, government, and
the regulated community to understand the magnitude of chemical
emissions in the United States; to compare chemical releases among
facilities and transfers of chemical wastes among States, industries,
and facilities; and perhaps most importantly, to assess the need to
reduce and where possible, eliminate these releases and other waste
management activities. TRI enables all parties interested in
environmental progress to establish credible baselines, to set
realistic goals, and to measure progress over time, in meeting those
goals. The TRI system provides a neutral yardstick by which progress
can be measured by all interested parties. TRI is an important tool in
empowering the Federal government, State governments, industry,
environmental groups, and the general public, to fully participate in
an informed dialogue about the environmental and human health impacts
of toxic chemical releases and other waste management activities.
Prior to EPCRA, the kind of information contained in the TRI
generally was nonexistent or unavailable to the Federal government,
State governments, emergency preparedness teams or the general public,
and often was not disclosed until after major impacts on human health
and the environment were evident. This ``after the fact'' disclosure of
information did little to help plan for or prevent such serious health
and environmental impacts. While permit data are generally cited as a
public source of environmental data, they are often difficult to
obtain, are not cross-media, and present only a limited perspective on
a facility's overall environmental performance. While other sources of
data are sometimes cited as substitutes for TRI data, based on its own
research, EPA is unaware of any other publicly available, nationwide
data base that provides multi-media, facility-specific release and
other waste management information to the public in a readily
accessible form. With TRI, and the real gains in understanding it has
produced, communities now know which industrial facilities in their
area release or otherwise manage as waste listed toxic chemicals.
Under EPCRA section 313, Congress set the initial parameters of
TRI, but also gave EPA clear authority to modify TRI in various ways,
including to change the toxic chemicals subject to reporting, the
facilities required to report, and the threshold quantities that
trigger reporting. By providing this authority, Congress recognized
that the TRI program would need to evolve to meet the needs of a better
informed public and to refine existing information. EPA has, therefore,
undertaken a number of actions to expand and enhance TRI. These actions
include expanding the number of reportable toxic chemicals by adding
286 toxic chemicals and chemical categories to the EPCRA section 313
list in 1994. Further, a new category of facilities was added to EPCRA
section 313 on August 3, 1993, through Executive Order 12856, which
requires Federal facilities meeting threshold requirements to file
annual TRI reports. In addition, in 1997 EPA expanded the number of
private sector facilities that are required to report under EPCRA
section 313 by adding seven new industrial groups to the list of
covered facilities. At the same time, EPA has sought to reduce the
burden of EPCRA section 313 reporting by actions such as delisting
chemicals that were
[[Page 691]]
determined not to meet the statutory listing criteria and establishing
an alternate reporting threshold of 1 million pounds for facilities
with 500 pounds or less of production-related releases and other
wastes. Facilities meeting the requirements of this alternate threshold
may file a certification statement (Form A) instead of reporting on the
standard TRI report, the Form R.
In today's actions, EPA is proposing enhanced reporting
requirements that focus on a unique group of toxic chemicals. These
toxic chemicals which persist and bioaccumulate in the environment are
more commonly referred to as persistent bioaccumulative toxics or PBTs.
To date, with the exception of facilities subject to the alternate
threshold exemption, EPA has not altered the statutory reporting
threshold for all listed chemicals. However, as the TRI program has
evolved over time and as communities identify areas of special concern,
thresholds and other aspects of the EPCRA section 313 reporting
requirements may need to be modified to assure the collection and
dissemination of relevant, topical information and data. Towards that
end, EPA is proposing to increase the utility of TRI to the public by
adding a number of chemicals that are toxic and that persist and
bioaccumulate in the environment to the section 313 list and by
lowering the reporting thresholds for a number of toxic chemicals that
have these properties. Toxic chemicals that persist and bioaccumulate
are of particular concern because they remain in the environment for
significant periods of time and concentrate in the organisms exposed to
them. EPA believes it is important that the public understand that
these persistent bioaccumulative toxic (PBT) chemicals can have serious
human health and environmental effects resulting from low levels of
release and exposure. Lowering the reporting thresholds for PBT
chemicals would ensure that the public has important information on the
quantities of these chemicals released or otherwise managed as waste,
that would not be reported under the current thresholds.
B. Use of EPCRA Section 313 to Focus on Chemicals that Persist and
Biaccumulate
As discussed in Unit VII.A. of this preamble, EPA is proposing to
lower the EPCRA section 313 reporting thresholds for certain PBT
chemicals. A chemical's persistence refers to the length of time the
chemical can exist in the environment before being destroyed by natural
processes. Bioaccumulation is a general term that is used to describe
the process by which organisms may accumulate certain chemicals in
their bodies. The term refers to both uptake of chemicals from water
(bioconcentration) and from ingested food and sediment residues. PBT
chemicals are therefore toxic chemicals that partition to water,
sediment, or soil and are not removed at rates adequate to prevent
their bioaccumulation in aquatic or terrestrial species. Chemicals that
persist and bioaccumulate have been found in shellfish, birds, human
adipose tissue, and other mammals. See Unit V. of this preamble for a
more detailed discussion of and definitions for the terms persistence
and bioaccumulation.
Review of existing data leads EPA to believe that, as a general
matter, the release to the environment of toxic chemicals that persist
and bioaccumulate is of greater concern than the release of toxic
chemicals that do not persist or bioaccumulate. Since PBT chemicals can
remain in the environment for a significant amount of time and can
bioaccumulate in animal tissues, even relatively small releases of such
chemicals from individual facilities have the potential to accumulate
over time to higher levels and cause significant adverse impacts on
human health and the environment. EPA believes that the availability of
information on PBT chemicals is a critical component of a community's
right-to-know. Therefore, it is particularly important to gather and
disseminate to the public relevant information on the releases and
other waste management activities of PBT chemicals.
Thus, for PBT chemicals, releases and other waste management
activities that occur at facilities that manufacture, process, or
otherwise use such chemicals in relatively small amounts are of
concern. Under current reporting thresholds, a significant amount of
the releases and other waste management activities involving PBT
chemicals are not being captured and thus the public does not have the
information needed to determine if PBT chemicals are present in their
communities and at levels that may pose a significant risk. By lowering
the section 313 reporting thresholds for PBT chemicals EPA would be
providing communities across the United States with access to data that
may help them in making this determination. This information could also
be used by government agencies and others to identify potential
problems, set priorities, and take appropriate steps to reduce any
potential risks to human health and the environment.
Several EPA offices have ongoing projects and programs that are
dealing with issues concerning PBT chemicals. EPA has established the
PBT planning group which is a coordinating body consisting of
representatives from various program offices throughout EPA that are
dealing with PBT chemicals. This group has developed a strategy to
reduce pollution from PBT chemicals through the application of
regulatory and non-regulatory authorities, with a strong emphasis on
pollution prevention. Under this initiative, the reporting of PBT
chemicals under EPCRA section 313 will provide data on PBT chemicals to
EPA, industry, and the public. The availability of that data can allow
all parties to identify and track releases of PBT chemicals and monitor
the progress of the programs designed to reduce the amount of PBT
chemicals entering the environment. The data will also allow EPA and
others to design prevention strategies that are focused and effective.
EPA is also participating in several international efforts to
reduce or eliminate pollution from PBT chemicals. These efforts include
the Commission for Environmental Cooperation (CEC) Process for
Identifying Candidate Substances for Regional Action under the Sound
Management of Chemicals Initiative, the United Nations Environment
Programme Persistent Organic Pollutants (POPs) Negotiations, and the
Canada-United States Strategy for the Virtual Elimination of Persistent
Toxic Substances in the Great Lakes Basin.
The program between the United States and Canada focuses on
pollution of the Great Lakes by PBT chemicals, which has been a matter
of great concern for both countries. EPA has established the Great
Lakes National Program Office (GLNPO) to develop and implement programs
to reduce pollution of the Great Lakes. GLNPO works in cooperation with
counterpart organizations in Canada, most notably Environment Canada,
to carry out its mission. The ``Final Water Quality Guidance for the
Great Lakes System'' (60 FR 15366, March 23, 1995) (FRL-5173-7)
identified ``Pollutants that are bioaccumulative chemicals of concern
(BCCs)'' among the ``Pollutants of Initial Focus in the Great Lakes
Water Quality Initiative.'' Working with that list, Canada and the
United States agreed on an initial list of chemicals identified as
``Substances Targeted by the Canada-United States Strategy for the
Virtual Elimination of Persistent Toxic Substances in the Great Lakes
Basin''
[[Page 692]]
(Ref. 1). A subset of the targeted substances is often referred to as
the ``Binational Level 1 List,'' and includes chemicals both countries
have committed to ``virtually eliminate'' from the Great Lakes. Virtual
elimination is to be attained by programs implemented voluntarily by
each country.
EPA discussed the issue of reporting on PBT chemicals under section
313 in its January 12, 1994 chemical expansion proposed rule (59 FR
1788) (FRL-4645-6). In the preamble to the proposed rule, EPA
specifically requested comment on whether PBT chemicals should be added
to the section 313 list. EPA also asked for comments on what
modifications to reporting requirements, such as lowering reporting
thresholds or modifying the de minimis exemption, would need to be made
in order to insure that release and transfer information would be
collected for such chemicals. In response to EPA's request for comments
on the reporting of PBT chemicals, 39 commenters responded, with 35 of
these commenters fully supporting such reporting under section 313. In
addition, of the over 620 comments EPA received on its 1997 proposal to
add a dioxin and dioxin-like compounds category, over 520 commenters
supported lowering the reporting thresholds for the proposed category.
Many commenters also suggested that EPA lower the reporting threshold
for all toxic chemicals that persist and bioaccumulate. EPA will
provide specific responses to these comments as part of any final rule
developed to add the dioxin and dioxin-like compounds category to the
section 313 list and lower the reporting thresholds.
C. Overview of EPA Process for Developing Its Proposal
This section presents a summary of the processes EPA used to: (1)
Develop the persistence and bioaccumulation criteria the Agency is
proposing to adopt for purposes of determining whether a chemical is
persistent and bioaccumulative under EPCRA section 313; (2) identify
the persistent and bioaccumulative chemicals the Agency has chosen to
propose for addition in this rulemaking; and (3) determine the
appropriate thresholds for the individual toxic chemicals the Agency
has identified as persistent and bioaccumulative. A more extensive
discussion of EPA's rationales for each of the decisions made during
this process is presented throughout the various other sections of this
Notice.
As noted in section B. of this unit, much work has already been
done, both nationally and internationally, to identify chemicals that
could reasonably be anticipated to persist and bioaccumulate. Having
determined, for the reasons discussed generally in section B. of this
unit, to lower the EPCRA section 313 thresholds for persistent
bioaccumulative toxic chemicals, EPA began by reviewing the criteria
develop by various organizations.
As discussed in further detail in Unit V.A-B. of this preamble, EPA
found that generally the various criteria for both persistence and
bioaccumulation clustered around two criteria. For persistence in
water, soil, and sediment, the criteria were grouped around half-lives
of 1 to 2 months and 6 months, and for persistence in air, either 2 or
5 days. Bioaccumulation criteria were grouped around bioaccumulation
factor and/or bioconcentration factor values of 1,000 and 5,000.
Bearing in mind that one of Congress's articulated purposes for EPCRA
section 313 was to provide local communities with relevant information
on the release and other waste management activities of chemicals in
their community, that may present a hazard, EPA determined that the
criteria that were most consistent with these purposes were, for
persistence, half-lives of 2 months for water, sediment, and soil, and
2 days in air, and for bioaccumulation, bioaccumulation/
bioconcentration factor values of 1,000 or greater.
EPA developed a preliminary list of chemicals for consideration in
this rulemaking by reviewing the chemicals on the Great Lakes
Binational Toxics Strategy, Level 1 list and chemicals that had
received high scores for persistence and bioaccumulation from EPA's
Office of Solid Waste's Waste Minimization Prioritization Tool (WMPT).
EPA dropped from further consideration in this rulemaking certain
pesticide chemicals included on the Level 1 list, for which assessments
were not yet complete. The screening process described here is not part
of this rulemaking, but was merely a process designed to identify
candidate chemicals for further consideration in this rulemaking. It
was not used to select chemicals for addition or to determine for which
chemicals a lower threshold would be warranted. The process was
intended to allow the Agency to establish internal priorities and to
focus its limited resources in this initial rulemaking on those toxic
chemicals that would result in significant environmental and public
information benefits. The fact that a chemical was not included, either
as a result of EPA's screening processes, or as a result of one of the
assessments conducted during the rulemaking, does not mean that EPA has
finally concluded that the chemical does not persist or bioaccumulate,
or that the chemical does not warrant any further consideration under
EPCRA section 313.
As an initial step in its rulemaking process, EPA examined the
underlying persistence and bioaccumulation data for each of the
chemicals that remained after the screening process, and measured the
chemicals against EPA's chosen criteria for persistence and
bioaccumulation. Only if the chemical met both criteria did EPA
determine that in this rulemaking it would be appropriate to lower the
EPCRA section 313 ``manufacture,'' ``processing,'' and ``otherwise
use'' reporting thresholds. In addition, for the chemicals that were
not yet listed under EPCRA section 313, EPA conducted a hazard
assessment, and determined, based on the weight of all of the evidence,
whether the chemicals met the statutory criteria for listing under
EPCRA section 313(d)(2). Note that the EPCRA section 313(d)(2)(C)
ecotoxicity criteria include a consideration of data on a chemical's
persistence and bioaccumulation (see section 313(d)(2)(C)(ii) and
(iii)).
In determining the thresholds for this rulemaking, EPA
preliminarily concluded that it would be appropriate to reflect the
levels of concern that the various PBT chemicals presented, based on
the differing degrees to which the chemicals persist and bioaccumulate.
The Agency ultimately chose to adopt a two-tier approach, and to
establish two separate thresholds to reflect the chemicals' varying
potentials to persist and bioaccumulate, as well as to reflect the
Agency's belief that the public has a greater right-to-know about
chemicals that can reasonably anticipated to be present in the
community at higher levels.
To reach the appropriate levels of concern, the Agency again
considered the range of criteria for persistence and bioaccumulation
adopted by various organizations, settling again on the criteria of
bioaccumulation/bioconcentration factor values of 1,000 and 5,000, and
half-lives for soil, sediment, and water of 2 and 6 months. Those
chemicals with a bioaccumulation/bioconcentration factor value of 1,000
or greater but less than 5,000, and with a soil, sediment, or water
half-life of 2 months or greater but less than 6 months, were
considered to be persistent bioaccumulative toxic chemicals, and
therefore a low, alternate threshold would be justified. However, those
toxic chemicals with a bioaccumulation/bioconcentration factor value of
5,000 or greater, and with
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a soil, sediment, or water half-life of 6 months or greater were
considered to be highly persistent bioaccumulative toxic chemicals, and
EPA determined that an even lower threshold would be appropriate.
Because of the unique issues associated with establishing EPCRA section
313 thresholds for the category of dioxin and dioxin-like compounds,
EPA is proposing a separate, and even lower, threshold for this
chemical category.
Finally, although EPCRA section 313(f)(2) does not compel the
Agency to consider the burden to industry resulting from a lower
threshold, EPA has determined it would be reasonable, in this
rulemaking, to include some consideration of the additional burden
involved in lowering the statutory thresholds. While EPA is willing to
consider reporting burden in determining appropriate thresholds for the
PBT chemicals in the rule, the Agency must be mindful that the authors
of EPCRA, while sensitive to the burdens EPCRA section 313 reporting
placed on industry, never intended this consideration to outweigh the
public's need for access to information concerning their potential
exposure to toxic chemicals. See, e.g., Congressional Record at 5315-16
and 5338-39 (debate on adoption of the Conference Report). In light of
the authors' concerns, the Agency has identified two alternate sets of
thresholds, which afford a greater or lesser degree of weight to the
estimates of industry burden, and is requesting comment on the
propriety of the degree to which burden should be taken into account in
this rulemaking, and which set of thresholds the Agency should adopt.
IV. Chemicals Proposed for Addition to EPCRA Section 313
A. Statutory Criteria
In an initial review of PBT chemicals that appear on the list of
chemicals of concern in the various PBT chemical initiatives, EPA has
identified seven chemicals and one category of chemicals that persist
and bioaccumulate in the environment that are not currently subject to
reporting under section 313. For these chemicals a hazard assessment
was conducted to determine if they meet the EPCRA section 313(d)(2)
criteria for listing. Although identification of these chemicals for
initial consideration has been based on their status as PBT chemicals,
their proposed addition is based solely on the determination that they
meet the EPCRA section 313(d)(2)(B) or (C) listing criteria. EPCRA
section 313(d)(2) sets out criteria for adding chemicals to the list of
chemicals subject to reporting under section 313. For a chemical (or
category of chemicals) to be added to the EPCRA section 313(c) list of
toxic chemicals, the Administrator must determine whether, in her
judgment, there is sufficient evidence to establish any one of the
following:
(A) The chemical is known to cause or can reasonably be
anticipated to cause significant adverse acute human health effects
at concentration levels that are reasonably likely to exist beyond
facility site boundaries as a result of continuous, or frequently
recurring, releases.
(B) The chemical is known to cause or can reasonably be
anticipated to cause in humans-
(i) cancer or teratogenic effects, or
(ii) serious or irreversible-
(I) reproductive dysfunctions,
(II) neurological disorders,
(III) heritable genetic mutations, or
(IV) other chronic health effects.
(C) The chemical is known to cause or can reasonably be
anticipated to cause, because of-
(i) its toxicity,
(ii) its toxicity and persistence in the environment, or
(iii) its toxicity and tendency to bioaccumulate in the
environment, a significant adverse effect on the environment of
sufficient seriousness, in the judgment of the Administrator, to
warrant reporting under this section.
EPA has published additional information on the Agency's
interpretation of the section 313(d)(2) and (3) criteria for adding
chemical substances from the section 313 list (59 FR 61432). All of the
chemicals being proposed for listing in this proposed rule have been
determined to cause serious or irreversible chronic effects at
relatively low doses or ecotoxicity at relatively low concentrations,
and thus are considered to have moderately high to high chronic
toxicity or high ecotoxicity. EPA believes that chemicals that induce
death or serious adverse effects on aquatic organisms at relatively low
concentrations (i.e., they have high ecotoxicity), have the potential
to cause significant adverse effects on the environment due to the
changes that these chemicals may cause in the population of fish and
other aquatic organisms. EPA believes that such chemicals can
reasonably be anticipated to cause a significant adverse effect on the
environment of sufficient seriousness to warrant reporting. Therefore,
in accordance with EPA's stated policy on the use of exposure
assessments (59 FR 61432), EPA does not believe that an exposure
assessment is appropriate for determining whether the chemicals
proposed for listing in this rulemaking meet the criteria of EPCRA
section 313(d)(2)(B) or (C).
B. Use of Predictive Techniques
Three of the chemicals being proposed for listing
(benzo(g,h,i)perylene, 3-methylcholanthene, and octachlorostyrene) have
been found to meet the EPCRA section 313(d)(2)(C) criteria for
ecotoxicity based on predicted aquatic toxicity values generated from
quantitative structure activity relationship (QSAR) equations and other
predictive techniques. As previously stated (58 FR 63500, December 1,
1993), EPA believes that, where no or insufficient actual measured
aquatic toxicity data exist upon which to base a decision, toxicity
predictions generated by QSARs and other predictive techniques may
constitute sufficient evidence that a chemical meets the section 313
listing criteria. EPA's authority to use such predictive techniques
derives from section 313(d)(2) of the statute, which states that EPA
shall base its listing determinations on, inter alia, ``generally
accepted scientific principles.'' EPA believes that the aquatic QSAR
equations that are in widespread use and show a high correlation
between predicted and measured aquatic toxicity values can be
considered to be ``generally accepted scientific principles'' and can
appropriately form the basis of a listing determination (Ref. 2).
C. Technical Review of Chemicals Proposed for EPCRA Section 313 Listing
Summaries of the results of the hazard assessments for the seven
chemicals and one chemical category that are being proposed for
addition to section 313 are provided below. Additional information and
more detailed discussions concerning the toxicity of these chemicals
can be found in the support documents in the docket for this
rulemaking. Commenters should consult the support documents and review
the studies contained and referenced in the docket for further details.
1. Benzo(g,h,i)perylene (CAS No. 191-24-2) (Ref. 2). The predicted
aquatic toxicity values for benzo(g,h,i)perylene, based on QSAR
analysis using the equation for neutral organics and an estimated log
Kow of 6.7, include calculated values of 0.030 milligrams
per liter (mg/L) for the fish 96-hour LC50 (i.e., the
concentration that is lethal to 50% of test organisms) and 0.0002 mg/L
for fish chronic toxicity, 0.012 mg/L for the daphnid 48-hour
LC50 and 0.027 mg/L for the 16-day chronic LC50,
and 0.03 mg/L for the algae 96-hour
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EC50 (i.e., the concentration that is effective in producing
a sublethal response in 50% of test organisms) with an algal chronic
toxicity of 0.012 mg/L. These predicted aquatic toxicity values
indicate that benzo(g,h,i)perylene is toxic at relatively low
concentrations and thus is highly toxic to aquatic organisms. EPA
believes that the evidence is sufficient to list benzo(g,h,i)perylene
on EPCRA section 313 pursuant to EPCRA section 313(d)(2)(C) based on
the available ecotoxicity information for this chemical.
2. Benzo(j,k)fluorene (fluoranthene) (CAS No. 206-44-0) (Ref. 2).
Benzo(j,k)fluorene or fluoranthene as it is more commonly called, has
been tested for complete carcinogenic activity by skin painting in
various strains of mice and for tumor-initiating activity using mouse
skin initiation-promotion assays and no significant activities were
detected in any of these studies. However, using newborn or preweanling
mice, there was evidence that the compound was capable of inducing lung
and liver tumors. In addition, a reactive metabolite of fluoranthene
has been shown to induce mammary tumors in rats.
The potential pulmonary carcinogenicity of fluoranthene was first
reported in a 24-week newborn mouse lung adenoma assay. Newborn Swiss-
Webster BLU:Ha (ICR) mice were given intraperitoneal injections of 0.7
or 3.5 mg fluoranthene in dimethyl sulfoxide (DMSO) on days 1, 8, and
15 after birth and observed for 24 weeks. Lung tumor incidence was
significantly increased in high-dose males (20 out of 27 versus 1 out
of 27 in the control) but not in low-dose males or females of both dose
groups. The pulmonary carcinogenicity of fluoranthene was confirmed
using newborn CD-1 mice. In addition, liver tumors were observed in
male mice after 9 months of treatment. In another study using newborn
CD-1 mice given 3.5 or 17.3 micromoles fluoranthene for 1 year
pulmonary and hepatic carcinogenic activities were also observed. The
lung tumor incidence was significantly increased in all dosed groups
(in males: 43% at the low-dose and 65% at the high-dose versus 17% in
the control group; in females: 35% at the low-dose and 86% at the high-
dose versus 12% in the control group) whereas only male mice had higher
incidence of liver tumors (64% at the low-dose and 100% at the high-
dose versus 17% in the control group).
A genotoxic, ``pseudo-bay'' region diol epoxide metabolite of
fluoranthene has been shown to induce mammary tumors in female CD rats.
In this study, lightly anesthetized 30-day-old rats were given two
injections of 2 or 10 micromoles of anti-2,3-dihydroxy-1,10b-epoxy-
10b,1,2,3-tetrahydro-fluoranthene in DMSO directly into mammary tissues
beneath the three left thoracic nipples and DMSO under the right
nipples. After 41 weeks, 85% of the treated groups developed
histologically confirmed mammary tumors, compared to 11% in DMSO
control group. The potential mammary carcinogenic activity of
fluoranthene itself remains to be studied.
Fluoranthene has been shown to be mutagenic in the Ames test, in a
Salmonella forward mutation assay (with potency comparable to that of
benzo[a]pyrene), and in a human diploid lymphoblast cell line. A
``pseudo-bay'' region diol epoxide has been detected as a metabolite
and found to be highly mutagenic and carcinogenic as well as capable of
binding to DNA. Besides genotoxic mechanisms, fluoranthene has also
been shown to be a potential immunosuppressive agent as indicated by
its ability to suppress B lymphopoiesis and induce apoptosis
(programmed cell death) in murine T cell hydridomas.
The International Agency for Research on Cancer concluded that
there is inadequate evidence to permit an evaluation of the
carcinogenicity of fluoranthene. EPA has listed the compound as a Group
D (not classifiable as to carcinogenicity in humans). However, in both
cases, recent studies indicating pulmonary and hepatic carcinogenicity
as well as mechanistic studies were not fully taken into account at the
time of the reviews.
Based on the overall ``weight of evidence'' for carcinogenicity,
genotoxicity, metabolism and mechanistic data and consideration of
structure-activity relationships, and despite the lack of dermal
carcinogenicity, fluoranthene should be classified as a Group ``C''
carcinogen under the ``weight of evidence'' approach of EPA's 1986
Guidelines for Carcinogen Risk Assessment (51 FR 33992, September 24,
1986) because of positive carcinogenicity data in one animal species.
Under EPA's 1996 Proposed Guidelines for Carcinogen Risk Assessment (61
FR 17959, April 23, 1996) fluoranthene would most appropriately fall in
the category ``likely'' to produce cancer in humans. EPA believes that
the evidence is sufficient for listing fluoranthene on EPCRA section
313 pursuant to EPCRA section 313(d)(2)(B) based on the available
carcinogenicity data for this chemical.
Section 313 contains a listing for polycyclic aromatic compounds
(PACs). All of the members of this category are listed based on
concerns for their carcinogenicity. Since part of the basis for listing
fluoranthene under section 313 is a concern for carcinogenicity this
chemical is being proposed for addition to the section 313 PACs
category.
A number of studies have been conducted on the ecotoxicity of
fluoranthene. Ecotoxicity values include a calculated 96-hour
LC50 of 3.9 mg/L for bluegill, a 96-hour LC50 of
0.04 mg/L for mysid shrimp, and a 96-hour LC50 of 5.0 mg/L
for a polychaete. Using standard acute toxicity tests,
benzo(j,k)fluorene has been tested in 12 freshwater species from 11
genera. For freshwater benthic species, the acute 96-hour
LC50 calculated values are 0.032 mg/L for an amphipod
(Gammarus minus), 0.070 mg/L for a hydra (Hydra americana), 0.17 mg/L
for an annelid (Lumbriculus variegatus), and 0.17 mg/L for a snail
(Physella virgata). For saltwater species, the 96-hour LC50
values are 0.051 mg/L for a mysid (Mysidopsis bahia), 0.066 mg/L for an
amphipod (Ampelisca abdita), 0.14 mg/L for a grass shrimp (Palaemonetes
pugio), and 0.50 mg/L for an annelid (Neanthes arenaceodentata).
Fathead minnows exposed to benzo(j,k)fluorene at a concentration of
0.0217 mg/L for 28 days in chronic early life-stage test showed a
reduction of 67% in survival and a 50.2% reduction in growth relative
to the controls. In a 28-day chronic study, mysids exposed to 0.021 mg/
L of benzo(j,k)fluorene showed a 26.7% reduction in survival and a
91.7% reduction in reproduction; at 0.043 mg/L all mysids died. In a
31-day study, mysids showed a reduction of 30% in survival, 12% in
growth, and 100% in reproduction relative to controls at a
concentration of 0.018 mg/L of benzo(j,k)fluorene. These aquatic
toxicity values indicate that benzo(j,k)fluorene is toxic at relatively
low concentrations and thus is highly toxic to aquatic organisms. EPA
believes that the evidence is sufficient to list benzo(j,k)fluorene on
EPCRA section 313 pursuant to EPCRA section 313(d)(2)(C) based on the
available ecotoxicity information for this chemical.
3. 3-Methylcholanthrene (CAS No. 56-49-5) (Ref. 2). 3-
Methylcholanthrene has been clearly shown to be a multi-target potent
carcinogen in a variety of studies with a potency that exceeds or is
comparable to that of the well known potent carcinogen benzo[a]pyrene.
3-Methylcholanthrene has been found to be a potent carcinogen in
rodents by a variety of routes of administration. It
[[Page 695]]
has been shown to induce skin tumors and local sarcomas by topical and
subcutaneous routes, respectively, with a potency higher than that of
benzo[a]pyrene. 3-Methylcholanthrene has induced lung tumors in mice by
intravenous injection and in addition to skin tumors it produced a 100%
incidence of leukemia in mice after repeated skin application.
Following oral administration, 3-methylcholanthrene induced hepatomas
in Wistar rats maintained on a low protein diet and in newborn suckling
albino mice, it also induced mammary tumors in young female rats,
induced forestomach tumors in rodents, and skin tumors in young rats.
Oral administration of 3-methylcholanthrene to hamsters induced
intestinal, mammary, and ovarian tumors. 3-Methylcholanthrene has been
shown to be positive in a wide variety of gene mutation assays, in cell
transformation assays using nine different cell types, and in both in
vitro and in vivo sister chromatid exchange assays. In vivo binding of
3-methylcholanthrene to DNA in mouse cells has also been demonstrated.
Considering structure-activity relationships, 3-methylcholanthrene
does contain the characteristic ``bay-region'' found in most
carcinogenic polycyclic aromatic hydrocarbons. Metabolism and
mechanistic data indicate that the bay-region 9,10-dihydrodiol of 3-
methylcholanthrene is a proximate carcinogen of this chemical in the
newborn mouse model and most likely also in the initiation-promotion
model with the bay-region diol epoxide being the ultimate carcinogen.
There is also some possibility that 1-hydroxylation of 3-
methylcholanthrene may be another additional metabolic activation
pathway.
Although not evaluated in EPA's IRIS data base, based on the
overall ``weight of evidence'' for carcinogenicity, genotoxicity,
metabolism, and mechanistic data and SAR consideration, 3-
methylcholanthrene would be classified as a Group B2 carcinogen (i.e.,
it is a probable human carcinogen) under the ``weight of evidence''
approach of EPA's 1986 Guidelines for Carcinogen Risk Assessment (51 FR
33992, September 24, 1986) (FRL-2984-3), and would fall in the category
``likely'' to produce cancer in humans under EPA's 1996 Proposed
Guidelines for Carcinogen Risk Assessment (61 FR 17959, April 23, 1996)
(FRL-5460-3). EPA believes that the evidence is sufficient for listing
3-methylcholanthrene on EPCRA section 313 pursuant to EPCRA section
313(d)(2)(B) based on the available carcinogenicity data for this
chemical.
Section 313 contains a listing for PACs. All of the members of this
category are listed based on concerns for their carcinogenicity. Since
part of the basis for listing 3-methylcholanthrene under section 313 is
a concern for carcinogenicity this chemical is being proposed for
addition to the section 313 PACs category.
The predicted aquatic toxicity values for 3-methylcholanthrene,
based on QSAR analysis using the equation for neutral organics and an
estimated log Kow of 7.05, include a calculated fish 96-hour
LC50 of 0.009 mg/L and a chronic fish toxicity value of
0.003 mg/L, a daphnid 48-hour LC50 of 0.005 mg/L and a 16-
day chronic LC50 of 0.015 mg/L, and an algae 96-hour
EC50 of 0.0105 mg/L with a calculated chronic toxicity value
of 0.014 mg/L. These predicted aquatic toxicity values indicate that 3-
methylcholanthrene is toxic at relatively low concentrations and thus
is highly toxic to aquatic organisms. EPA believes that the evidence is
sufficient to list 3-methylcholanthrene on EPCRA section 313 pursuant
to EPCRA section 313(d)(2)(C) based on the available ecotoxicity
information for this chemical.
4. Octachlorostyrene (CAS No. 29082-74-4) (Ref. 2). A short-term
(28-day) study and a subchronic (90-day) feeding study of rats
demonstrated that octachlorosytrene can cause adverse liver, thyroid,
and kidney effects. In the 28-day study, hepatomegaly and a dose-
dependent increase in the prevalence and severity of liver injury
(histological changes) were seen in both male and female rats. In male
rats only, histological changes in the thyroid (including increased
epithelial height, reduced colloid density, and angular collapse of
thyroid follicles) were observed; suggesting male rats are more
sensitive to the thyroid-toxic effects of octachlorosytrene than
females. In the 90-day study, a number of adverse effects not detected
in the 28-day study were observed. Increased liver, kidney, and spleen
weights were observed in both male and female rats, while only
increased liver weights were seen in the 28-day study. Dose-dependent
histological effects were seen in the liver, thyroid, and kidney of
treated animals in the 90-day study. Kidney lesions, not detected in
the 28-day study, became more pronounced with increasing dose in the
90-day study. Kidneys of treated rats showed glomerular adhesions
associated with proteinaceous casts in the lower nephron and focal
tubular. In addition, changes in hepatic enzyme activities and serum
biochemical parameters were noted in both the 28- and 90-day studies. A
1 year oral study of rats (20 per gender and per dose group) exposed
the animals to 0, 0.05, 0.5, 5.0, and 50 parts per million (ppm) of
octachlorostyrene in the diet. Morphological changes in the liver,
kidney, and thyroid were similar to the effects observed in the 28 and
90-day studies. The 1 year study found the histological effects in
affected organs to be the most sensitive endpoint. Although the
histological changes could be detected at doses as low as 0.05 ppm, at
these low doses changes were judged to be minor and probably adaptive.
The No Observed Adverse Effect Level (NOAEL) was judged by the study
authors to be 0.5 ppm in the diet or 0.031 milligrams per kilogram per
day (mg/kg/day). Correspondingly, the Lowest Observed Adverse Effect
Level (LOAEL) would be 5.0 ppm in the diet or 0.31 mg/kg/day for
significant histological changes in the liver, kidney, and thyroid.
Statistically significant increases in organ weights, such as those
discussed above, are gross indicators of damage to the organ and
significant histological changes in organs indicate serious damage and
impaired organ functions. EPA believes that the evidence is sufficient
for listing octachlorostyrene on EPCRA section 313 pursuant to EPCRA
section 313(d)(2)(B) based on the available hepatic, nephric, and
thyroid toxicity data for this chemical.
The ecotoxicity data for octachlorostyrene are very limited.
However, based on QSAR analysis using a measured log Kow of
7.7, an estimated 14-day LC50 value of 6 micrograms per
liter (g/L) for guppies has been calculated for
octachlorosytrene. In addition, toxicity data for hexachlorobenzene, a
chemical analogue for octachlorostyrene due to its structural
similarity, is available. Hexachlorobenzene inhibits photosynthesis in
algae at a concentration of 30 g/L and a subchronic
EC50 value of 16 g/L has been calculated for
daphnids. These predicted and analogue aquatic toxicity values indicate
that octachlorostyrene is toxic at relatively low concentrations and
thus is highly toxic to aquatic organisms. EPA believes that the
evidence is also sufficient to list octachlorosytrene on EPCRA section
313 pursuant to EPCRA section 313(d)(2)(C) based on the available
ecotoxicity information for this chemical.
5. Pentachlorobenzene (CAS No. 608-93-5) (Ref. 2). A subchronic,
90-day,
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feeding study on pentachlorobenzene has been conducted that utilized 8
experimental groups (3 male, 5 female) of 10 rats each. A statistically
significant increase in kidney weights, decreased heart weights, and an
increase in hyaline droplets in proximal kidney tubules was noted in
male rats receiving 8.3 mg/kg/day (125 ppm in diet). Female rats
receiving the next highest dose, 18 mg/kg/day (250 ppm in diet), and
their offspring showed increased liver/body weight ratios. At higher
doses, up to 72 mg/kg/day (1,000 ppm in diet), animals of both sexes
showed hepatocellular enlargement, increase in adrenal and kidney
weights, increased white blood cell (WBC) counts, and lowered red blood
cell (RBC) indices. The lowest dose of 8.3 mg/kg/day is considered a
LOAEL from this study. The results of this subchronic feeding study
were used by EPA to establish an oral reference dose (RfD) for
pentachlorobenzene. A second 13-week feeding study in rats and mice
used lower feed concentrations of pentachlorobenzene than the above
study (i.e., 0, 33, 100, 330, 1,000 or 2,000 ppm) and 10 animals of
each sex per group per species. Evidence of kidney, liver,
hematological, and thyroid toxicity were observed, supporting the
results of first study. In male rats, histological lesions included a
spectrum associated with hydrocarbon or hyaline droplet nephrology.
Nephropathy was seen in rats of both sexes. Both rats and mice
exhibited centrilobular hepatocellular hypertrophy. The data from these
subchronic exposure feeding studies indicate that oral exposure to
pentachlorobenzene may have serious toxic effects to the kidney and
liver as well as serious hematological effects. Statistically
significant increases in organ weights, such as those discussed above,
are gross indicators of damage to the organ and significant
histological changes in organs indicate serious damage and impaired
organ functions.
In one study, dose groups of 10 female weanling rats were exposed
to 0, 125, 250, 500, or 1,000 ppm of pentachlorobenzene in feed. The
dams were treated for 67 days, then mated with untreated males and
treated continually through gestation and nursing. Suckling pups of
dams receiving 18 mg/kg/day (250 ppm in feed) and higher doses of
pentachlorobenzene through gestation and weaning developed tremors. The
pups and dams at this dose or higher also exhibited increased liver/
body weight ratios. Almost all (28% survival rate from day 4 to
weaning) of the pups in the high dose group (1,000 ppm) died before
weaning. In another study using a different strain of rats, groups of
20 mated female rats were treated with 0, 50, 100, or 200 mg/kg/day of
pentachlorobenzene by gavage at days 6 to 15 of gestation. The authors
of the study reported a significant increase in skeletal abnormalities
(extra ribs) in pups whose mothers had been treated with all levels of
pentachlorobenzene. At 200 mg/kg/day of pentachlorobenzene an increase
in sternal defects, a decrease in fetal body weights, and a
nonsignificant decrease in the number of fetuses per litter was
reported.
EPA believes that the evidence is sufficient for listing
pentachlorobenzene on EPCRA section 313 pursuant to EPCRA section
313(d)(2)(B) based on the available hepatic, nephric, hematological,
and developmental toxicity data for this chemical.
A number of ecotoxicity studies have been conducted on
pentachlorobenzene including studies on algae, daphnids, shrimp, and
fish. Aquatic acute toxicity calculated values for pentachlorobenzene
include a sheepshead minnow 96-hour LC50 of 0.83 mg/L,
bluegill sunfish 96-hour LC50s of 0.25 mg/L and 0.3 mg/L, a
guppy 96-hour LC50 of 0.54 mg/L, and a mysid shrimp 96-hour
LC50 of 0.16 mg/L. These acute toxicity values indicate that
pentachlorobenzene is toxic at relatively low concentrations and thus
is highly toxic to aquatic organisms. Additional acute toxicity
calculated values include algae 96-hour EC50s of 1.98 mg/L
and 6.78 mg/L, and daphnia 48-hour EC50s of 1.3 mg/L and
5.28 mg/L. Considering pentachlorobenzene's persistence and
bioaccumulation potential (discussed in Unit V.C.1. of this preamble)
pentachlorobezene is considered highly toxic to aquatic organism even
at these higher concentrations. EPA believes that the evidence is
sufficient to list pentachlorobenzene on EPCRA section 313 pursuant to
EPCRA section 313(d)(2)(C) based on the available ecotoxicity
information for this chemical.
6. Tetrabromobisphenol A (CAS No. 79-94-7) (Ref. 2). In a study
completed in 1985 and submitted to EPA in 1992, tetrabromobisphenol A
was shown to produce developmental effects in rats. The study appears
to have followed testing guidelines applicable at the time it was
conducted and uses an adequate number of animals (25 per dose group) to
allow statistical analysis. In the study, tetrabromobisphenol A was
administered to rats by gavage in corn oil from day 6 through 15 of
gestation at doses of 0, 2.5, 10, or 25 mg/kg/day. The study found a
LOAEL of 10 mg/kg/day for significantly reduced fetal body weights when
analyzed on a litter basis. At 25 mg/kg/day, slight maternal toxicity,
increased frequency of resorption and delayed ossification and other
abnormalities in offspring were observed. Malformations and
developmental delays included significant increases in the litter
incidences of fetuses with enlarged hearts, rear limb malformations,
and ``remarkable'' delays in the ossification of the skull, vertebrae,
ribs, and pelvis. Two other studies of rats using fewer animals (five
per dose group) did not report evidence of developmental toxicity in
offspring although higher doses were used and maternal death was
reported. However, it is likely that these other studies lacked the
sensitivity necessary to detect the effects reported in the first
study. EPA believes that the evidence is sufficient for listing
tetrabromobisphenol A on EPCRA section 313 pursuant to EPCRA section
313(d)(2)(B) based on the available developmental toxicity data for
this chemical.
A number of ecotoxicity studies have been conducted on
tetrabromobisphenol A including studies on algae, daphnids, shrimp,
oysters, and fish. Aquatic acute toxicity calculated values for
tetrabromobisphenol A include a fathead minnow 96-hour LC50
of 0.54 mg/L, a rainbow trout 96-hour LC50 of 0.40 mg/L, a
bluegill sunfish 96-hour LC50 of 0.51 mg/L, and a daphnid
48-hour LC50 of 0.96 mg/L; mysid shrimp 96-hour
LC50 values ranged from 0.86 to 1.2 mg/L depending on the
age of the shrimp. Aquatic chronic toxicity calculated values from a
Daphnia 21-day study resulted in a Maximum Acceptable Toxicant
Concentration (MATC) that was between 0.30 and 0.98 mg/L (geometric
mean 0.54 mg/L) based on a significant reduction in reproduction rates;
a fathead minnow 35-day study resulted in a MATC that was calculated to
be between 0.16 and 0.31 mg/L (geometric mean 0.22 mg/L) based on
adverse effects on embryo and larval survival. These aquatic toxicity
values indicate that tetrabromobisphenol A is toxic at relatively low
concentrations and thus is highly toxic to aquatic organisms. EPA
believes that the evidence is sufficient to list tetrabromobisphenol A
on EPCRA section 313 pursuant to EPCRA section 313(d)(2)(C) based on
the available ecotoxicity information for this chemical.
7. Vanadium (CAS No. 7440-62-2) and Vanadium Compounds (Ref. 2).
Vanadium is currently listed under
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section 313 with the qualifier (fume or dust). EPA is proposing to
remove the fume or dust qualifier for vanadium and to add a vanadium
compounds category. Therefore, EPA is presenting the following
information as the basis for determining that vanadium other than fume
or dust forms and vanadium compounds meet the section 313(d)(2)
criteria for listing chemicals.
a. Algae. Vanadium has been shown to have toxic effects in algae.
One study found that growth of Chlorella decreased at vanadium
concentrations as low as 100 parts per billion (ppb), and at 50 to
1,000 ppm production was lowered by 25 to 34% compared to the controls.
Different results were obtained in a second study where, for Chlorella,
the maximum stimulatory effects on biomass production and chlorophyll
synthesis were found at 500 ppb vanadium in the medium. Inhibitory
effects on dry weight and chlorophyll content were found at
concentrations of approximately 25 ppm vanadium, and growth was found
to cease at 100 ppm vanadium. The toxic threshold for vanadium content
in the algae was determined to be 150 to 200 nanograms per gram (ng/g)
dry weight. Another study found the growth of the dinoflagellate
Ceratium hirundinella to be inhibited by 0.1 ppm vanadium. In marine
studies, acute toxicity tests on Dunaliella marina, Proocentrum micans,
and Asterionella japonica with sodium metavanadate produced 9-day
LC50 values of 0.5 ppm, 3 ppm, and 2 ppm respectively.
Vanadium appears to influence cell division processes in algae. It
has been reported that 3 ppb vanadium as sodium vanadate prevented
complete synchronization of Bumilleriopsis filiformis. In another study
it was found that, in the range of vanadium concentration known to
stimulate Chlorella pyrenoidosa, toxic effects on cell division were
apparent. In continuous light, in the presence of 20 ppb vanadium as
NH4VO3, mean cell size increased significantly,
with maximal increase occurring at 0.5 ppm vanadium. These large cells
had giant nuclei with multiple chromosomes. In addition, synchronous
growth of the algae with vanadium ceased after three division periods,
after which a division occurred, which generally produced larger than
normal autospores. It was postulated that during growth, normal
duplication of genetic material occurred, producing nuclei with
multiple sets of chromosomes. However, subsequent nuclear division was
inhibited by vanadium and the subsequent division of autospores did not
occur, producing giant cells with large nuclei. In another study it was
observed that ultrastructural changes in enlarged cells of Scenedesumus
obliquus induced by growth at elevated concentrations of vanadium (0.8
to 9 ppm), included thickened cell walls, and larger numbers of
vacuoles, starch granules, and lipid droplets.
One study has reported that the 15-day LC50 for an
estuarine and salt-water green alga (Dunaliella marina) is 0.5 mg/L of
sodium metavanadate and that the 15-day LC50 for a salt-
water pennote diatom (Asterionella japonica) is 2 mg/L.
b. Invertebrates. Vanadium is commonly found in trace amounts in
shell fish and crustaceans. The uptake of vanadium in molluscs,
crustaceans, and echinoderms indicated that besides the food pathway,
direct surface sorption processes are of major importance in the
bioaccumulation of the metal. However, very few vanadium toxicity tests
have been conducted with invertebrates. Reported toxicity values
include 9-day LC50 values for Nereis diversicolor (worm),
Mytilus galloprovincialis (mussel), and Carcinus maenas (crab) of 10,
35, and 65 ppm vanadium (as NaVO3 in the seawater)
respectively. These moderately high values are supported by another
report that found that the critical concentration for vanadium in
Mytilus edulis was between 50 and 100 ppm.
In a study of the toxicity of the heavy metals selenium, zirconium,
and vanadium on the freshwater ciliated protozoan Tetrahymena
pyriformis, the addition of 20 ppm vanadium as vanadyl sulfate
significantly lowered the growth and locomotor rate (measured as
swimming speed) of the organism. In another study, a median survival
time (MST) of 8 hours was reported for Daphnia magna in media
containing 30 ppm vanadium added as vanadate.
c. Vertebrates. Studies with American flagfish (Jordanella
floridae) indicated a 96-hour LC50 of 11.2 ppm vanadium.
Growth and survival in a 96-hour test was depressed, particularly in
the larvae, at 0.17 ppm vanadium. At a concentration of 0.041 ppm there
was stimulation of growth and reproductive performance in female fish.
The sublethal threshold for toxicity of vanadium was estimated to be
0.08 ppm.
Studies have reported that vanadium is moderately toxic to juvenile
rainbow trout (Salmo gairdneri) and whitefish (Coregonus clupeaformis)
with 96-hour LC50 values of 6.4 and 17.4 ppm respectively,
with toxicity increasing slightly with decreasing pH. Pronounced
histopathological lesions were observed in gills and kidneys of trout
exposed to sublethal concentrations of vanadium, with damage increasing
with increased exposure to the metal. Vanadium induced premature
hatching of eyed eggs at concentrations from 44 to 595 ppm. Curiously,
eyed eggs of trout were 200 to 300 times more resistant to vanadium
than fingerlings, and the metal did not appear to induce
histopathological lesions in the developing embryos. It appeared that
juvenile whitefish avoided vanadium concentrations of 500 ppm or higher
in the test water.
It has also been reported that vanadium causes dose-related
histopathological effects on the lamellae of gills in juvenile rainbow
trout, suggesting that the gills are a critical site for the lethal
action of vanadium. Of the three toxic materials tested (vanadium,
nickel, and phenol), vanadium was that most potent lethal agent with a
96-hour LC50 of 10 ppm vanadium.
It has been reported that for vanadium the 7-day LC50
values for trout are within a narrow range, from 1.9 to 6.0 ppm
vanadium, added as V2O2. Toxicity decreased with
increasing water hardness, and was greater at pH 7.7, where
H2VO4 was predicted to be the predominant
vanadium ion. A second study reported the effects of vanadium on two
life stages of brook trout, Salvelinus fontinalis, observing that the
alevins of the fish were less sensitive to vanadium that were
yearlings, the 96-hour LC50 being 24 and 7 mg/L
respectively. Another study reported a 96-hour LC50 of 0.62
ppm for Therapon jarbua with vanadium presented as
V2O5.
The rainbow trout (Salmo gairdneri) is one of the most commonly
used fish for toxicity studies; for this species the LC50
value for vanadium was reported to be 5.6 mg/L. Increasing the exposure
time resulted in progressively lower LC50 values, the lowest
being 1.99 mg/L for an 11-day exposure period. Similar results have
been reported where the LC50 values decreased from 4.34 mg/L
for 5 days exposure to 1.95 mg/L for 14 days. Neither of these groups
was able to define a minimum lethal level for rainbow trout. Other
studies indicated that small rainbow trout are more resistant than
larger fish to vanadium pentoxide. In general rainbow trout eggs were
10 to 15 times more resistant to pentavalent vanadium than fingerlings.
Some of the aquatic toxicity data discussed above are at relatively
low concentrations indicating that vanadium is highly toxic to certain
aquatic organisms. In addition, considering
[[Page 698]]
vanadium's persistence and bioaccumulation potential (discussed in Unit
V.C.1. of this preamble), EPA also believes that vanadium is highly
toxic to aquatic organisms at the higher concentrations. EPA believes
that the evidence is sufficient to list vanadium and vanadium compounds
on EPCRA section 313 pursuant to EPCRA section 313(d)(2)(C) based on
the available ecotoxicity information for vanadium and vanadium
compounds.
It has been suggested that the bioaccumulation data for vanadium
are insufficient to support the designation of vanadium as
bioaccumulative based on the criteria proposed in this rulemaking. As
such, while EPA is proposing to add vanadium compounds and all forms of
vanadium to EPCRA section 313, the Agency is not proposing to revise
the reporting thresholds for vanadium or vanadium compounds at this
time. EPA requests comment on the sufficiency of the bioaccumulation
data for vanadium.
EPA requests comment on its proposal to require reporting on the
chemicals listed above under EPCRA section 313 and on the data
supporting the proposed listings.
V. Persistence and Bioaccumulation: Criteria, Data Evaluation
Methods, and Technical Review of Chemicals
This is EPA's first effort under section 313 to review chemicals
for their persistence and bioaccumulation properties and it is limited
to a relatively small group of chemicals. EPA may review additional
chemicals in the future to determine if they should be considered
persistent and bioaccumulative under section 313 and, if not already on
the section 313 list, whether they should be added. In pursuing this
action, EPA first established criteria that should be used under
section 313 for determining if a chemical persists or bioaccumulates in
the environment. The criteria were then applied to determine whether
the chemicals included in this review can reasonably be anticipated to
persist and bioaccumulate in the environment. The chemicals initially
reviewed were drawn from two lists of persistent and bioaccumulative
chemicals, including the Binational Level 1 list (Ref. 1) and chemicals
that received high scores for persistence and bioaccumulation in the
initial version of the Waste Minimization Prioritization Tool (WMPT)
developed by EPA's Office of Solid Waste were also considered (Ref. 3).
The chemicals on these lists were reviewed as part of the screening
process which is not part of this rulemaking. Finally, included in this
initial review were the chemicals included in the dioxin and dioxin-
like compounds category that EPA has proposed for addition to the
section 313 list (62 FR 24887, May 7, 1997) (FRL-5590-1). This proposed
rule only presents the data for those chemicals for which assessments
have been completed under the initial review; it does not eliminate any
chemical from possible future designation as persistent or
bioaccumulative or from future consideration for lower reporting
thresholds for purposes of reporting under section 313. Any future
lowering of the reporting thresholds for PBT chemicals will be done
through rulemaking.
A. Persistence
A chemical's persistence refers to the length of time the chemical
can exist in the environment before being destroyed (i.e., transformed)
by natural processes. The environmental media for which persistence is
measured or estimated include air, water, soil, and sediment with water
being the medium for which persistence values are most frequently
available. It is important to distinguish between persistence in a
single medium (air, water, soil, or sediment) and overall environmental
persistence. Persistence in an individual medium is controlled by
transport of the chemical to other media, as well as transformation to
other chemical species. Persistence in the environment as a whole is a
distinct concept. It is based on the observations that the environment
behaves as a set of interconnected media, and that a chemical substance
released to the environment will become distributed in these media in
accordance with the chemical's intrinsic (physical/chemical) properties
and reactivity. For overall persistence, only irreversible
transformation contributes to net loss of a chemical substance. This
unit discusses those aspects of persistence that are important to
consider in determining a chemical's persistence in the environment and
sets forth the criteria that EPA used for determining that a chemical
is persistent for purposes of reporting under section 313.
1. Measurement of persistence in individual media. A common measure
of persistence in individual environmental media is a chemical's half-
life, or the amount of time necessary for half of the chemical present
to be eliminated from the medium. Thus, after one half-life, one half
of the original amount of the chemical remains, after two half-lives
one quarter of the original amount remains, after three half-lives one
eighth remains, and so on. If other potentially confounding factors are
ruled out, measured half-lives will normally reflect the rate(s) of one
or more transformation processes. Confounding factors include, for
example, transport of the substance to another medium; sorption,
complexation or sequestration; and reversible changes in speciation.
Transformation may occur by a variety of processes. In air, for
chemicals in the gas phase, the most important process contributing to
their destruction is oxidation by photochemically generated hydroxyl
radicals (Ref. 4). However, photolysis and oxidation by ozone and
nitrate radicals are also important transformation processes for some
chemicals. In water, soil, and sediment the chief process resulting in
net loss for most chemical substances is microbial degradation (i.e.,
biodegradation), but hydrolysis, direct and indirect photolysis and
abiotic oxidation/reduction reactions may also play a role. Whether a
given measured half-life reflects only one of these processes or more
than one depends on the molecular structure of the chemical in
question, and on the experimental design. The experiment may be
designed to measure a net (overall) half-life for the medium of
interest, or it may be designed to focus on a specific transformation
process.
In the environment, degradation half-lives for chemical substances
depend not only on chemical properties and structure, but also on
characteristics of the surrounding environment. There are many
environmental factors that can affect a substance's half-life,
including, for example, temperature, pH, sunlight intensity, hydroxyl
radical concentration, and the activity of the microbial community. As
a result, there is substantial variability in environmental half-lives
in both space and time, and this variability is reflected in the
available literature data.
Variability in persistence data can be illustrated by means of
examples. Webster et al. (Ref. 5) discuss the atmospheric oxidation of
2,2',4,4'-tetrachlorobiphenyl, which reacts with hydroxyl radicals in a
reaction that is dependent upon temperature and hydroxyl radical
concentration (Ref. 6). Based on measured radical concentrations (Ref.
7), they estimated that in mid-latitudes in July at 15 deg.C the half-
life is approximately 2 weeks, whereas in January at -5 deg.C it
increases to 6 months at the same location. Even greater differences
are expected when comparing polar and tropical latitudes. A second
example is the hydrolysis of lindane (Ref. 5). Based on reliable
measured data, the half-life for hydrolysis in ocean water at pH 8.1
[[Page 699]]
varies from greater than 100 years at 0 deg.C to 75 days at 30 deg.C
(Ref. 8). Finally, Vink and Zee (Ref. 9) measured rates of
transformation of several pesticides in surface waters of The
Netherlands and found large variations in half-lives. Half-lives ranged
from 70 to 173 days for aldicarb, 1 to 139 days for simazine, 2 to 347
days for methoxone (MCPA), and 3 to 1,400 days for mecoprop. In this
example, further analysis showed that much of the variability could be
attributed to environmental factors that either directly or indirectly
affect microbial activity.
Variability in rates of biodegradation is especially important
because this is the dominant transformation process in soil and water/
sediment for the majority of organic chemicals. This variability tends
to be less predictable than the variability in abiotic transformation
processes such as atmospheric oxidation and hydrolysis. The first two
examples above demonstrate the dependence of half-lives for hydroxyl
radical oxidation in the atmosphere and hydrolysis in water on
measurable environmental parameters (i.e., temperature, hydroxyl
radical concentration, and pH). However, even when these variables are
controlled, measured rate constants can easily vary by an order of
magnitude and this is reflected in literature data (e.g., Refs. 8 and
10).
2. Data evaluation methods for persistence in each environmental
medium. The ideal situation in which to evaluate persistence would be
one in which sufficient data are available for a chemical substance of
interest, from studies using environmentally relevant protocols, to
fully characterize the distribution of its half-lives. To ``fully
characterize'' the distribution means to collect enough data to allow
calculation of a mean and standard deviation of half-lives for each
substance and environmental medium. Field studies, such as are often
conducted to determine pesticide fate in the environment, are generally
considered the most informative studies if properly conducted. The
problem is that persistence is difficult to study in the field due to
the high expense typical of these studies, the unpredictability of
weather, and so on. Moreover, it is often difficult or impossible to
determine a meaningful half-life for transformation due to an inability
to eliminate or adjust for transport of the test substance out of the
medium of interest. The ideal situation is rarely if ever achieved, and
even with relatively well-tested chemicals it is necessary to use
laboratory data and, often, estimates of half-lives.
In both laboratory studies and estimation methods, it is common to
focus on specific transformation processes. Thus, for example, a common
technique is to study biodegradability by collecting a ``grab sample''
of soil or natural water/sediment, transporting the sample to the
laboratory, spiking the sample with the chemical of interest, and
measuring the chemical's disappearance over time while running controls
to rule out contribution of other fate processes. EPA believes it is
appropriate to use grab sample studies in addition to field studies.
Where experimental conditions can be optimized to mimic those in the
field and the balance and interactions between microbial species in the
sample can be preserved, the results of grab sample biodegradation
studies are expected to be sufficiently representative of field results
to allow general characterization of biodegradative persistence in
environments similar to those from which the grab sample was collected.
In view of these limitations on existing persistence data, to
determine a chemical's persistence for purposes of section 313
reporting, EPA adopted an approach to data selection and review that
emphasizes experimental data but utilizes both laboratory and field
data, as well as estimated half-lives in certain situations. Although
there are certain limitations to existing persistence data, EPA
believes that for the chemicals included in this proposed rule the
available data are sufficient to make a reasonable determination
regarding their environmental persistence.
a. Air. For air, the rate constant for the reaction of hydroxyl
radicals in the vapor phase with the chemical of interest, whether
experimentally determined or estimated, was usually the only
information available. Very few experimental data were available for
the chemicals included in this proposed rule, and EPA therefore used
the Atmospheric Oxidation Program (AOP) (Ref. 11), which is based on
the estimation method of Kwok and Atkinson (Ref. 12), to estimate rate
constants for this process. Half-lives for air were then calculated
using default hydroxyl radical concentrations based on published
monitoring data for relatively pristine (3 x 105 radicals
per cubic centimeter (cm3)) and polluted (3 x 106
radicals/cm3) air. In many cases the chemical of interest is
expected to exist partially or mainly in the particulate phase. Because
half-lives for the particulate phase are likely to be higher, where
data on particulate phase half-lives were available they were given
greater weight in judging overall half-life in air than data on gas-
phase hydroxyl radical reaction. Data from studies in which emissions
from wood smoke had been exposed to sunlight were available for several
PACs and thus they were given greater weight in judging overall half-
life in air for these compounds. Photolysis may also be an important
transformation process in air, and half-lives for photolysis were used
in the evaluation of overall atmospheric half-life if experimental data
were available and indicated that the process was significant at light
wavelengths in the visible range (greater than 290 nanometers (nm)).
As indicated above, because of insufficient experimental data EPA
used the estimation method of Kwok and Atkinson (Ref. 12) to calculate
rate constants for hydroxyl radical oxidation in the vapor phase in the
atmosphere, and these data provided the basis for air half-lives for
most of the chemicals included in this proposed rule. The Atkinson
methodology, as embodied in the Atmospheric Oxidation Program (AOP)
(Ref. 11), is generally accepted as the method of choice for estimation
of atmospheric oxidation potential and is currently in use worldwide.
b. Water, sediment, and soil. For the surface water/sediment
compartment, biodegradation is the dominant transformation process for
most of the chemicals included in this proposed rule. Therefore,
biodegradation data from field or grab sample studies were most often
used as the basis for overall half-lives for this environmental
compartment. Field studies were preferred, but if only grab sample
studies were available the half-life for this compartment was expressed
as a range of values. Data from longer term laboratory studies were
preferred over other data. Although laboratory-determined half-lives
for direct or indirect photolysis (when this process was important and
data were available) were almost always lower, the data were not used
to determine half-lives for the medium unless from aquatic simulation
tests. The rationale is that most of the chemicals included in this
proposed rule are expected to sorb strongly to particulate and
suspended material in water, and be removed from the surface layers
where sunlight penetration is most significant. Hydrolysis data were
considered in the determination of overall water/sediment half-life for
chemicals with hydrolyzable functional groups if data were available.
Evaluation of half-life data for the soil compartment was similar
to that for the water/sediment compartment. As with water/sediment, if
only grab sample studies were available, the half-life for
[[Page 700]]
the compartment was expressed as a range of values, but here the
possibility of photolysis on the soil surface was noted. Field study
data were not qualified in this manner because it was assumed that
study plots had been exposed to all relevant transformation processes
simultaneously. Photolysis was not considered quantitatively when soil
half-lives were based on grab sample data because of the inherent
limitations of available photolysis data. Most such available data are
for photolysis in water, organic solvents, or water/solvent mixtures,
but photolysis rates under these conditions are rarely similar to those
for the same chemical sorbed to soil.
As noted above only biodegradation data from field or grab sample
studies were used in the determination of overall half-lives for water/
sediment and soil. No data from microbial pure culture screening (e.g.,
Ready Biodegradability tests) or biotreatment studies were used in the
evaluation because these types of studies cannot be used to derive
environmentally relevant biodegradation half-lives since the
environment is much more complex than a microbial pure culture. Data
(biodegradation or other) on persistence in benthic sediments were
generally not available for the chemicals included in this proposed
rule. Data were available for some polychlorinated biphenyls (PCBs);
however, and such data were considered in the determination of overall
water/sediment half-life for PCBs.
3. Standards for acceptability of persistence data. The standards
listed below were applied in determining the acceptability of data for
soil and water/sediment. At a minimum, studies needed to have
information on the following parameters:
Identity of the tested chemical.
Study type: grab sample (and what medium the sample came
from, i.e., water; soil; sediment; some combination thereof) or field
test.
Degradation rate; or data in table or figure for
degradation versus time, from which a rate could be calculated; or rate
data already expressed as a half-life or rate constant.
Analytical method used to measure degradation.
Initial concentration (dosing) of tested chemical.
Although a lack of the types of information listed below was not
necessarily grounds for rejection, a study was considered more valuable
if information was given on:
Purity of the tested chemical.
Temperature of incubation (or field temperature in the
case of field studies).
Location and characteristics (especially, likelihood of
prior contamination and thus development of an acclimated microbial
population) of field sites or sites from which grab samples were
collected, as appropriate.
Mass balance obtained with respect to starting level of
the test chemical.
Degree of replication of test vessels, field plots, etc.
Use of appropriate controls, especially sterile controls
to account for any abiotic loss of the tested chemical.
For field and grab sample studies it was important, for
interpretation of results in relation to the overall transformation
half-life, that processes leading to transport of the chemical out of
the medium of interest be ruled out. Which processes were of importance
was not always easy to ascertain or predict, but usually this could be
done to a first approximation. With respect to field tests especially,
but also grab sample tests, special attention was given to the
possibility of volatilization (e.g., removal of the volatilized
chemical could falsely be attributed to transformation) and sorption.
The following factors were generally considered grounds for
rejection of biodegradation studies (Ref. 13). They do not necessarily
apply to other types of studies.
Less than 10% of the tested chemical initially present was
lost in the study.
Degradation rate was determined from a curve for which the
r2 value was low (generally, 0.5 or lower).
There was reason to believe that abiotic reactions may
have contributed to the observed rate of degradation, but there was no
sterile control (not applicable to field studies).
Incubation temperature was less than 10 deg.C, or was
otherwise ``extreme'' (not applicable to field studies).
Grab samples, if applicable, were held in laboratory
storage for an excessive period of time prior to test initiation
(generally, greater than several days).
Initial test chemical concentration was high enough to
lead to the possibility that toxicity to the microbial population
accounted wholly or partially for low observed degradability (if
applicable); generally, levels of the tested chemical greater than 500
mg/L for water and greater than 1,000 mg/L for soil were grounds for
suspicion.
For many of the chemicals included in this proposed rule,
biodegradation was judged to be the critical process controlling
overall persistence in soil or water, but data were available for one
or the other but not both media. Under these circumstances EPA assumed
that half-lives for biodegradation are roughly comparable in the two
compartments. This assumption is based on independently derived but
consistent results reported by Boethling, et al. (Ref. 13) and Federle,
et al. (Ref. 14). In the first study (Ref. 13), measured half-lives
from existing literature data were collected for a wide variety of
organic chemicals whose biodegradability had been tested using both
soil and water/sediment grab samples (but not necessarily in the same
study or by the same investigator). Mean ratios of half-life in water
to half-life in surface soil were then calculated for the 20 study
chemicals. These ratios varied widely but their overall mean was
approximately one. Therefore, it is reasonable to assume that
biodegradation in aerobic surface waters is about as fast as
biodegradation in soil. Federle et al. (Ref. 14) compared
biodegradation rates under various conditions in much the same fashion,
but they utilized experimental data generated de novo in carefully
controlled laboratory tests. Scaling factors (ratios of half-lives) for
river water versus soil varied widely as observed in the first study
(Ref. 13), but the overall mean was again approximately one.
EPA requests comment on its methodology for determining persistence
in the absence of chemical-specific data.
4. Numerical criteria for persistence in each environmental medium.
Numerous organizations and internationally negotiated agreements have
set numerical criteria for environmental persistence, many of which
have been developed through consensus processes (Ref. 15). A half-life
in water of greater than 4 days is used by EPA's Office of Pesticide
Programs (OPP) to trigger bioaccumulation testing of pesticides in fish
(Ref. 16). Under the Clean Air Act Amendments of 1990 a list of
chemicals of priority concern was developed using a half-life in
surface waters of greater that 15 days (Ref. 17). A half-life of 30
days for surface waters was used to identify persistent chemicals on
the Toxic Substances Control Act Chemical Substances Inventory (Ref.
18). A number of Canadian projects, many dealing with the Great Lakes
basin, have developed lists of chemicals for various actions using a
half-life in water criterion of greater than 50 or 56 days with some of
the projects also using a sediment half-life criterion of 50 or 56 days
or in some cases 180 days (Ref. 15). Another Canadian project, the
Canadian Toxic Substances Management Policy (TSMP), used less
conservative half-life
[[Page 701]]
values of 6 months in water and 2 years in sediment with an air half-
life of 5 days (Ref. 19). Under the North American Free Trade Agreement
Commission for Environmental Cooperation (NAFTA-CEC), final screening
criteria are under review that use half-life persistence criteria of
greater than 6 months for water, 6 months for soil, 12 months for
sediment, and 2 days for air (Ref. 20 and 21). Half-life criteria
established for persistent chemicals under the United Nations Economic
Commission for Europe, Convention on Long-Range Transboundary Air
Pollution (UNECE-LRTAP) Protocol on POPs are 2 months for water, 6
months for soil, 6 months for sediment, and 2 days for air (Ref. 20 and
22). In negotiation of the LRTAP POPs Protocol, Germany proposed
somewhat more conservative half-life values of 2 months for water,
soil, and sediment and 2 days for air (Ref. 20 and 22). The Chemical
Manufactures Association (CMA) in its policy for identifying PBT
chemicals (Ref. 23) and the International Council of Chemical
Associations (ICCA) criteria for identifying persistent organic
pollutants (POPs) (Ref. 24) have both used half-life criteria of 180
days for surface water, 360 days for soil, and 5 days for air. In
addition, in preparations for scheduled negotiations for the United
Nations Environment Program (UNEP) Global Negotiations on POPs an
analysis was prepared that discusses international criteria for
chemical persistence (Ref. 20).
The above criteria for persistence in water, soil, and sediment
tend to cluster around two half-lives, 1 to 2 months and 6 months. A
persistence half-life criterion of 6 months seems adequate to ensure
that chemicals acknowledged by many groups to be the most persistent
are captured, for example the chemicals on the Binational Level 1 list
or the chemicals under consideration in the UNEP global POPs
negotiations (Ref. 20). But it may be inadequate to capture other
chemicals that persist long enough to bioaccumulate to toxic levels.
Any chemical exhibiting such properties would be missed by a 6-month
criterion.
A 2-month half-life criterion for persistence in water would be
consistent with many of the criteria discussed above. In addition, 2
months represents the approximate duration of standard aquatic
bioconcentration and chronic toxicity tests, and is therefore thought
to be adequate for detecting most long-term toxic effects as well as
any tendency for a chemical to accumulate in fatty tissue of aquatic
organisms. For example, among current, internationally harmonized
Office of Prevention, Pesticides and Toxic Substances (OPPTS) test
guidelines in the 850 series are methods for fish (Ref. 25) and oyster
(Ref. 26) bioconcentration factors (BCF), for which maximum recommended
test durations are 28 to 60 and 28 days, respectively. Test guidelines
for ecotoxicity include methods for daphnid chronic toxicity (Ref. 27),
mysid shrimp chronic toxicity (Ref. 28), fish early-life stage toxicity
(Ref. 29), and tadpole sediment subchronic toxicity (Ref. 30), for
which the recommended maximum test durations are 21 days, 28 days, up
to 60 days post-hatch, and 30 days, respectively. Sixty days is also
sufficient to encompass nearly all bioconcentration data in the
Japanese Chemicals Inspection and Testing Institute (CITI) data base
(Ref. 31), which contains data from carp bioconcentration tests, mostly
of 42 or 56 days' duration, for more than 400 chemicals tested under
the Chemical Substances Control Law (CSCL) of Japan. Further, most
reliable fish bioconcentration data in EPA's AQUIRE data base (Ref. 32)
are from 32-day tests or other tests of comparable duration. Based on
the available information, EPA believes the use of a 2-month half-life
criterion for persistence in water would be an appropriate criterion to
use for determining whether a chemical is persistent in water for
purposes of section 313.
As with water, the various groups discussed above have set
persistence criteria for soil and sediment that range from 2 to 12
months. As discussed under section A.3. of this unit, two separate
studies (Refs. 13 and 14) have suggested that biodegradation in aerobic
surface water can be assumed to be about as fast as biodegradation in
soil. Therefore, it is appropriate to set the half-life criterion for
soil at the same value as for water; i.e., 2 months. Similar
considerations apply to the selection of a sediment persistence
criterion. Very few data on persistence of chemicals in benthic
sediments are available. Deeper layers of aquatic sediment are surely
anaerobic, and this is especially likely if the levels of organic
matter are high. Boethling et al. (Ref. 13) found that anaerobic
biodegradation in flooded soil was on average 3 to 4 times slower than
aerobic degradation in surface soil. But surficial sediments are likely
to be aerobic and for this situation it is logical to use the same
half-life as for the overlying water (i.e., 2 months). In actuality,
the precise point in depth at which sediments become anaerobic varies
from site to site and is not predictable. Therefore, EPA believes that
it is appropriate to use the water criterion for both water and
sediment.
The persistence criteria for air selected or proposed by the
organizations discussed above are either 2 or 5 days (Ref. 33). As part
of the analysis of the UNEP Global Negotiations on POPs (Ref. 20) both
theoretical and empirical arguments were presented that support a half-
life criterion of 2 days for air. The analysis suggested that the air
persistence criterion mainly pertains to the ability of a chemical to
persist in air for a sufficient amount of time to be transported to
remote regions. For long range transport corresponding to transoceanic
or transcontinental distances (i.e., 2,500 miles) to occur, a chemical
needs to persist in the air between 7 and 10 days. For a 2-day half-
life a significant amount (1/16) of a chemical initially released to
air will remain after 8 days. The analysis also concluded that for the
chemicals on the initial UNEP list of 12 POPs, all exceeded or were
close to the 2-day half-life criterion for air.
The 5-day half-life air criterion proposed by some groups would be
sufficient for only 2 half-lives at best to occur in a 10-day transit
time. This implies that concern for long-range transport in air should
only exist if at least \1/4\ of the original amount of a chemical
released remains after long range transport. However, depending on the
quantity of the chemical originally released, amounts below \1/4\ of
that originally released may still be of toxicological significance,
especially for chemicals that persist and bioaccumulate. Moreover, even
greater amounts of a chemical may be deposited closer to the original
source and in much less time than it takes for long range transport.
Thus, under a 2-day half-life criterion the amount of an airborne
chemical that is available to be deposited at shorter distances can be
significant. For example, after 4 days the amount of a chemical with a
2-day half-life in air that will remain available for deposition is \1/
4\ of the original amount released and the amount deposited for a 5-day
half-life would be even greater. It has been noted (Ref. 34) that not
all chemicals that have been identified as of concern for persistence
and bioaccumulation are long-range pollutants, with some POPs with
certain properties tending to undergo rapid deposition close to their
sources rather than more widespread distribution. This is especially
relevant to reporting under section 313 which seeks (among other
things) to provide information
[[Page 702]]
concerning chemicals present in local communities. These considerations
suggest that the 5-day air criterion is not sufficiently inclusive.
For the purposes of determining whether a toxic chemical is
persistent in the environment under section 313, EPA used a half-life
criterion of 2 months for water/sediment and soil and a half-life of 2
days for air. Given the above discussions, EPA believes that, for
purposes of reporting under section 313, these values are appropriate
for determining whether a toxic chemical is persistent in the
environment and will persist long enough in the environment to
bioaccumulate or be transported to remote locations. Under these
criteria, if a toxic chemical meets any one of the media specific
criteria, then it is considered to be persistent. Thus if a toxic
chemical's half-life in water or sediment or soil is equal to or
greater than 2 months or greater than 2 days for air then the toxic
chemical is considered to be persistent for purposes of section 313.
Note that when considering persistence in connection with the potential
for a toxic chemical to bioaccumulate, meeting the air half-life
criteria alone would not be sufficient, since a chemical's potential to
bioaccumulate is usually dependent on it being persistent in either
water, sediment, or soil. In determining whether the chemicals in this
proposal were persistent, EPA did not rely solely on the persistence in
air.
EPA solicits comment on the use of the 2 month criterion in this
rulemaking.
5. Persistence in the multimedia environment. The environment may
be viewed as a set of interconnected media: air, water, sediment, and
soil. When a chemical substance is introduced into the environment it
becomes distributed among the individual media according to its
chemical properties and reactivity, and characteristics of the
environment. For example, a chemical released to air may degrade
quickly by any of several transformation processes, or it may be
deposited on soil, vegetation or surface water, depending on its
volatility, tendency to sorb to particulate matter in the atmosphere,
prevailing rates of precipitation and particle deposition, and so on.
Likewise, a chemical released to surface waters or soils may degrade
quickly, or it may volatilize or, in the case of soil, migrate through
surface layers and eventually reach ground water. All intermediate
forms of chemical distribution behavior are also possible.
In a closed system, thermodynamics determine the distribution of a
chemical at equilibrium, absent irreversible transformation of the
chemical. Under these conditions the chemical's volatility, as
reflected by its Henry's Law constant, and its hydrophobicity, as
reflected by its n-octanol/water partition coefficient, are the primary
determinants of the final distribution. The tendency to move from one
medium to another in response to thermodynamic forces is referred to as
partitioning. Partitioning may have a marked effect on the overall
persistence of a chemical in the multimedia environment. A chemical may
have a relatively long half-life in one medium, but, even if released
directly to that medium, may rapidly partition to another where its
degradation rate is different. For example, if a volatile chemical that
is relatively persistent (i.e., has a long half-life) in water and soil
but is rapidly oxidized in the atmosphere is released to water or soil,
the chemical's persistence in the receiving medium will be relatively
unimportant, as it will quickly volatilize, then degrade in air. The
overall persistence of the chemical will be much lower than predicted
from transformation half-lives for soil and water alone.
The way in which a chemical enters the environment is also an
important consideration. Using the example above, a volatile chemical
that is emitted to soil or water will have a different and higher
overall persistence than if the same substance is emitted directly to
air. This is because the process of moving from one environmental
medium to another--called intermedia transport--is time dependent.
Intermedia transport is complex and a full characterization includes a
suite of mass transfer coefficients, rain rates, and rates of aerosol
and dry deposition, sediment deposition and resuspension, and soil
water and solids runoff (Ref. 35).
Multimedia mass balance models offer the most convenient means to
estimate overall environmental persistence from information on sources
and loadings, chemical properties and transformation processes, and
intermedia partitioning. For the chemicals included in this proposed
rule EPA used an approach based on the EQC model (Ref. 35) to estimate
overall environmental persistence. Overall persistence estimated in
this way is used as an additional factor, in conjunction with reaction
half-lives for individual media, bioaccumulation/bioconcentration
factors, etc., in justifying actions proposed in this rule.
The EQC model is based on the fugacity approach first delineated by
Mackay (Ref. 36) and subsequently applied to numerous environmental
processes (Ref. 37). It uses an ``evaluative environment'' in which
environmental parameters such as bulk compartment dimensions and
volumes (e.g., total area, volume of soil and sediment, etc.) are
standardized, so that overall persistence for chemicals with different
properties and rates of transformation may be compared on an equal
basis (Ref. 38). EPA used a version of the EQC level III model (Ref.
35) which was modified to focus on net losses by deleting model terms
for advective losses (movement out of the evaluative environment of air
and water potentially containing a chemical) and sediment burial (Ref.
5). In this version of the model only irreversible transformation
contributes to net loss of a chemical.
The overall persistence obtained from this model is calculated as
the total amount in the evaluative environment when steady state is
achieved, divided by the total loss rate. The results thus obtained are
neither an overall environmental half-life nor a compartment (or
transformation)-specific half-life; rather they are equivalent to an
environmental residence time. When only irreversible transformation
contributes to net loss--i.e., under the conditions of this version of
the EQC model--overall environmental persistence times can be converted
to half-lives by multiplying the former by ln 2 (i.e., 0.693). The
overall half-life calculated in this way is for dissipation in the
environment as a whole and cannot be related directly to any individual
compartment. EPA has performed this calculation and the results are
discussed in Unit V.C.3. of this preamble.
In this analysis EPA used the highest, lowest, and mean values for
the ranges of half-lives identified as described above, as inputs to
the model. In addition to reaction half-lives for air, water, and soil,
the EQC model requires half-lives for the sediment compartment.
Measured values were used where available, but since there were few
such data, where biodegradation was the rate-determining process, the
half-life in the surface layer of sediments was assumed to be the same
as that for aerobic biodegradation in the water column. The rationale
is that sediment surface layers are likely to be aerobic, and therefore
rates of biodegradation will be similar at the sediment-water interface
and in the water column.
It has been proposed that reaction half-lives for input into
multimedia mass balance models like the EQC model be expressed as
lognormal distributions with defined standard
[[Page 703]]
deviations, the standard deviation being derived by assigning default
values if adequate experimental data are unavailable (Ref. 5). Overall
environmental persistence can then be expressed as a distribution and a
sensitivity analysis can be conducted to identify which reaction half-
lives are most critical in determining overall persistence. Another
result of the sensitivity analysis may be to show that one or more
compartmental half-lives can be assumed to be infinite without having a
marked effect on the overall environmental persistence.
While meeting any one of the medium-specific criteria for
persistence in water, soil, or sediment is sufficient to classify a
toxic chemical as persistent for purposes of section 313, EPA also
considers the results of multimedia modeling. If the results of
multimedia modeling indicate that a toxic chemical does not meet the
persistence criteria then, EPA may exclude that chemical from further
consideration as persistent. The use of multimedia modeling results to
override the medium-specific persistence data will only be considered
if all model inputs are judged to be accurate. For example, if the
multimedia modeling results are being driven by a chemical's half-life
in air but that half-life is not considered to be very reliable, then
EPA does not believe that the multimedia modeling should override the
medium-specific criteria. EPA will make a case-by-case determination
for any chemical that is not considered persistence on the basis of
multimedia modeling.
EPA solicits comments on this overall approach to the use of
multimedia modeling as discussed in this proposed rule, and on any
actual or proposed modifications to the fate model described above.
B. Bioaccumulation
Bioaccumulation is a general term that is used to describe the
process by which organisms may accumulate chemical substances in their
bodies. The discussions and data on bioaccumulation in this proposed
rule deal strictly with aquatic organisms because most of the
bioaccumulation data are from aquatic studies. This is not to imply
that bioaccumulation cannot occur in non-aqueous environments. The term
bioaccumulation refers to uptake of chemicals by organisms both
directly from water and through their diet (Ref. 39). EPA has defined
bioaccumulation as the net accumulation of a substance by an organism
as a result of uptake from all environmental sources (60 FR 15366). The
nondietary accumulation of chemicals in aquatic organisms is referred
to as bioconcentration, and may be described as the process through
which a chemical is distributed between the organism and environment
based on the chemical's properties, environmental conditions, and
biological factors such as an organism's ability to metabolize the
chemical (Ref. 40). EPA has defined bioconcentration as the net
accumulation of a substance by an aquatic organism as a result of
uptake directly from the ambient water through gill membranes or other
external body surfaces (60 FR 15366). A chemical's potential to
bioaccumulate can be quantified by measuring or predicting the
chemical's bioaccumulation factor (BAF). EPA has defined the BAF as the
ratio of a substance's concentration in tissue of an aquatic organism
to its concentration in the ambient water, in situations where both the
organism and its food are exposed and the ratio does not change
substantially over time (60 FR 15366). A chemical's potential to
bioaccumulate can also be quantified by measuring or predicting the
chemical's bioconcentration factor (BCF). EPA has defined the BCF as
the ratio of a substance's concentration in tissue of an aquatic
organism to its concentration in the ambient water, in situations where
the organism is exposed through water only and the ratio does not
change substantially over time (60 FR 15366). This Unit discusses those
aspects of determining bioaccumulation that are important to consider
in assessing whether a particular chemical will bioaccumulate in the
environment.
1. Use of BAFs versus BCFs. In general, because BAFs consider the
uptake of chemicals from all routes of exposure they are considered
better predictors of the accumulation of chemicals within fish than
BCFs which only consider uptake of chemicals directly from water. EPA
reached this same conclusion with regard to the use of BAFs in setting
criteria for the protection of the Great Lakes. Specifically, EPA
stated that BAFs were a better predictor of the concentration of a
chemical within fish tissues in the Great Lakes System because they
include consideration of the uptake of contaminants from all routes of
exposure (60 FR 15366). However, considering all routes of exposure
greatly complicates the analysis of bioaccumulation and the calculation
of BAFs. Biomagnification and trophic transfer via the food chain must
be considered in such determinations. Also, the percent lipid content
of fish at certain trophic levels must be factored in or normalized for
developing BAFs for non-polar chemicals (60 FR 15366). Thus, the BAF
value for a chemical may be much higher than its BCF value when these
other parameters are considered; the former is much more difficult to
calculate and more assumptions must be made.
Measured BAFs are based on field measurements of concentrations of
chemicals in various biota and water. Thus, BAFs will vary depending on
where in the food chain one samples organisms for analyses. For
example, a carp (an omnivore, lower in the food chain) will have a
different BAF than a pike (a top predator, high in the food chain and
at a high trophic level). BCFs and BAFs are not mutually exclusive of
one another but can be related. A predicted BAF can be derived by
multiplying a laboratory-derived BCF by a food-chain multiplier (FCM)
(defined as the ratio of BAF to an appropriate BCF) or by multiplying
an estimated BCF by a FCM value. BAFs predicted by using FCMs include
many but not all of the environmental fate processes (for example,
metabolism) and interactions that affect bioaccumulative chemicals.
When these processes or interactions are significant, predicted BAFs
will be larger than field-derived BAFs. Therefore, BAFs measured in the
field are preferred. An additional complicating factor in determining
BAFs is the interconnectivity of the water column and sediments in
aquatic ecosystems. This means that chemical residues in fish can also
be predicted via biota-sediment accumulation factors (BSAFs) which use
the concentration of the chemical in sediment as a reference point (60
FR 153661).
Although BAFs can be measured or calculated, a BCF value is more
commonly measured or predicted because such measurements do not require
the consideration of the often complex issues of food and sediment
exposure required for BAF determinations. EPA has been using BCF values
as an indicator of bioaccumulation potential for industrial chemicals
and pesticides for many years (Ref. 41). In addition, well-known and
established test guidelines for determining BCF values exist (Refs. 25
and 26). These test guidelines suggest that only a limited number of
aquatic species be tested, mainly fathead minnows and/or oysters and
occasionally rainbow trout, which helps to reduce variability in test
results. BCF values for many organic chemicals have been calculated
using these test guidelines, particularly for some chemicals tested
under TSCA section 4. In addition, equations for predicting
[[Page 704]]
BCF values have been developed that correlate well with measured values
(Refs. 40 and 42). The most recent of these equations was developed by
comparing predictions with measured data for 694 chemicals and is
believed to provide a significantly better fit to the existing measured
data than other methods (Ref. 40). Due to the consideration of
additional sources of exposure, BAF values are usually higher than BCF
values, thus using a BCF value should not usually over-predict the
potential for bioaccumulation in aquatic species.
The number of measured or predicted BAFs available is limited while
measured BCFs exist for many chemicals and can be predicted rather
easily. While BAFs may be better predictors of the concentration of a
chemical in fish, in the absence of appropriately measured or predicted
BAFs, a BCF value can be used as an indicator of a chemical's potential
to bioaccumulate. For purposes of determining if a chemical is
bioaccumulative under section 313 EPA will use BAF values when
available and BCF values for toxic chemicals for which appropriately
determined BAFs do not exist. EPA requests comment on this approach.
2. Predicting BAFs and BCFs. Appropriately measured BAF or BCF
values are always the data of first choice, however these values are
expensive to measure if done properly and thus are not as readily
available as predicted values. In the absence of valid measured data,
EPA believes that it is appropriate to use predicted BAF and BCF values
since available prediction methods provide values that correlate well
with measured data. EPA has published procedures for predicting BAFs
(60 FR 15366). However, since BAFs require consideration of complex
exposure paths, BCFs are the more commonly predicted indicator of a
waterborne chemical's potential to bioconcentrate in aquatic organisms.
BCF values are often predicted from a chemical's octanol/water
partition coefficient (Kow). A chemical's Kow is
a ratio of the chemical's concentration in the n-octanol phase to its
concentration in the aqueous phase in an equilibrated two-phase n-
octanol-water system. The information is usually reported as the common
logarithm (base 10) of Kow, log Kow, rather than
as Kow itself. A chemical's log Kow provides an
indication of the chemical's ability to bioconcentrate based on the
assumption that bioconcentration is a thermodynamically driven
partitioning process between water and the lipid phase of the exposed
organism, and therefore can be modeled using n-octanol as a surrogate
for biological lipids. Thus, the relationship between log
Kow and BCF is valid only for chemicals that bioconcentrate
in tissues containing lipids (Refs. 40 and 41). BCFs are usually
predicted from regression equations of the general form: log BCF = a
log Kow + b where a and b empirically determined constants
(Ref. 43). The equation, log BCF = 0.79 log Kow -0.4, has
been determined to provide a good correlation with measured BCF values
(Ref. 42) and has been used by EPA for a number of years. In addition,
the bilinear model method developed by Bintein, et al. (Ref. 44)
provides a much better correlation with measured BCF values for
chemicals with log Kow values greater than 6. Recently a
study was conducted that improved the correlation between prediction
equations and measured BCF values (Ref. 40). The new equation,
developed by comparing predictions with measured data on 694 chemicals,
is log BCF = 0.77 log Kow -0.7 + Fi, where Fi are
correction factors for structural characteristics of the chemical in
question (Ref. 40). This new equation is believed to provide an even
better fit to the existing measured BCF data base.
EPA request comments on its methodology for predicting BCF values
and on the use of predicted BCFs for quantifying the bioaccumulation of
chemicals in this rulemaking when measured BCFs are not available.
3. Standards for acceptability of measured BAF and BCF data.
Measured BAF or BCF values are the preferred source of bioaccumulation
data if the values are from appropriately conducted studies. EPA has
published procedural and quality assurance requirements for field-
measured BAFs for the Final Water Quality Guidance for the Great Lakes
System (56 FR 15366). While these requirements are specific to the
Guidance for the Great Lakes System, they do provide a basis for some
general factors to be considered when reviewing measured BAF data, for
example:
The trophic level of the fish species tested should be
determined.
For organic chemicals, the percent lipid should be either
measured or reliably estimated for the tissue used in the determination
of the BAF.
The concentration of the chemical in the water should be
measured in a way that can be related to particulate organic carbon
(POC) and/or dissolved organic carbon (DOC) and should be relatively
constant during the steady-state time period.
For organic chemicals with log Kow greater than
four, the concentrations of POC and DOC in the ambient water should be
either measured or reliably estimated.
For inorganic and organic chemicals, BAFs should be used
only if they are expressed on a wet weight basis; BAFs reported on a
dry weight basis should not be converted to wet weight unless a
conversion factor is measured or reliably estimated for the tissue used
in the determination of the BAF.
EPA also used some general guidelines for selecting measured BCF
values for this proposed rule. The goal was to limit the number of
individual measured BCF values to be considered to 10 for any given
chemical (where applicable), and to select a single recommended BCF
from the available measured values for each chemical. The general
guidelines used were:
Data obtained by the kinetic method were preferred to data
from the equilibrium method, especially for chemicals with high log
Kow values, which are less likely to have reached
equilibrium in standard tests.
For equilibrium-method studies a BCF value in the middle
of the range of values with the longest exposure times was selected,
especially for substances with high log Kow values (for the
same reason as noted above).
Low exposure concentrations of the chemical were favored
in order to minimize the potential for toxic effects and maximize the
likelihood that the total concentration of the chemical in water was
equivalent to the amount that was bioavailable.
Data obtained under flow-through conditions were selected
whenever possible.
Data were rejected if significant contamination of the
exposure medium by food, excreta, or other adsorbents was suspected,
since this may reduce the bioavailability of the test chemical.
Warm-water fish were preferred to cold-water fish since
more data were available for warm-water species. EPA also considered
whether the measured BCF values were from studies that were conducted
in a manner consistent with the well-known and established test
guidelines for determining BCF values (Refs. 25 and 26).
4. Sources of BAF and BCF data for chemicals included in this
proposed rule. The data used to assess the bioaccumulative properties
of the chemicals included in this proposed rule includes a mixture of
both predicted and measured BAF and BCF values. Appropriately measured
BAF and BCF values were used where available, but in the absence of
appropriately measured values, predicted values were used. Measured
[[Page 705]]
BCF values were identified mainly from a review of a data base of BCF
values for 694 chemicals compiled by Syracuse Research Corporation
(SRC) to support the development of an improved BCF prediction equation
(Ref. 45). Other BCF values were predicted using the equation developed
by Meylan, et al. (Ref. 40). Additional measured or predicted BCF
values were obtained from previous chemical reviews, hazard
assessments, TSCA section 4 activities, and other references. In
addition, measured BAF values for certain chemicals were obtained from
EPA's Great Lakes Water Quality Initiative Technical Support Document
for the Procedure to Determine Bioaccumulation Factors (Ref. 46). The
record for this proposed rule includes a document that explains the
origin of the BAF or BCF value selected for the each PBT chemical (Ref.
47).
The measured BCF values contained in the data base developed by SRC
were obtained primarily from the U.S. EPA's AQUIRE data base (Ref. 32);
a large data base of BCF values collected by the Japanese Chemicals
Inspection and Testing Institute (CITI) (Ref. 31); the National Library
of Medicine's Hazardous Substances Data Bank (HSDB) (Ref. 48); and
sources referenced in the Environmental Fate Data Base (EFDB) (Refs. 49
and 50). Most data were retrieved from AQUIRE (277 chemicals) and CITI
(479 chemicals). Only fish BCF data were collected for the data base,
which does not contain data for any other species. The record for each
chemical contains up to 10 individual BCF measurements, and a single
recommended value selected from the listed measurements which was
chosen following EPA-approved selection criteria (Ref. 47). If
available, data were also collected for each individual BCF value on
fish species, concentration of test substance, percent lipid in test
organism, test method (equilibrium or kinetic), and fish tissue on
which measurements were based (whole body, fillet, or edible tissue). A
separate field in each data base record contains the rationale for
selection of the recommended BCF value. Printouts of the data base
records for each PBT chemical whose BCF data came from this data base
are included in the record for this proposed rule (Ref. 47).
5. Numerical criteria for bioaccumulation. EPA used a BAF/BCF
numerical criterion of 1,000 for determining if a chemical is
bioaccumulative for purposes of section 313. The initial basis for the
consideration of a BCF value of approximately 1,000 as an indicator of
high bioaccumulation potential is linked to information developed at a
meeting sponsored by the American Society for Testing and Materials
held in 1976 which was published in the open literature two years later
(Ref. 51) and which was recently reaffirmed (Ref. 52). Additional
support for the use of a numerical cut off of 1,000 for bioaccumulation
has developed over a number of years. In chemical reviews conducted
under TSCA, EPA uses BCF values of between 100 and 1,000 to indicate a
medium concern for the potential bioaccumulation of a chemical and a
BCF of 1,000 or more to denote a high concern (Refs. 53 and 54). EPA's
Duluth Laboratory (Refs. 55 and 56) studied 83 chemicals, 59 of which
had predicted BCF values of less than 188 (log Kow less than
3.5). Of the 59 chemicals, none had predicted BCF values that were high
enough to have demonstrable environmental effects. This indicated that
bioconcentration testing should not be necessary for chemicals with
predicted BCF values of less than 188 (Ref. 54). However, there were
some chemicals whose BCF values were between 188 and 1,000 (log
Kow 3.5 to 4.35) that were found to bioconcentrate
significantly (Ref. 55). Thus EPA established a BCF range of equal to
or greater than 100 and less than 1,000 to indicate a medium concern
for bioaccumulation and a BCF value of greater than 1,000 for a high
concern. In addition, the usefulness of the BCF cut off value of 1,000
for high concern was affirmed in an EPA-sponsored workshop (the Testing
Triggers Workshop) which was conducted in 1982 (Ref. 57). Furthermore,
a BCF value of 1,000 has been used by many groups over the years to
denote chemicals of high concern for bioaccumulation potential,
especially with regard to the need to conduct long-term chronic
toxicity testing (Refs. 51, 58, 59, 60, 61, 62, and 63).
As with BCF values, EPA believes that it is appropriate, for
section 313 purposes, to use a criterion of 1,000 for BAF values. Since
BAF values include consideration of additional routes of exposure it is
appropriate to use a criterion that is at least equal to that set for
BCF values. Support for a BAF criterion of 1,000 also comes from the
Final Water Quality Guidance for the Great Lakes System (60 FR 15366).
In that document EPA stated that bioaccumulation of persistent
pollutants is a serious environmental threat to the Great Lakes Basin
Ecosystem and that chemicals identified as bioaccumulative chemicals of
concern (BCCs) (i.e., those with BAF values greater than 1,000) would
receive increased attention and more stringent controls. That final
Guidance designated as BCCs those chemicals with human health BAFs
greater than 1,000 that were derived from certain field-measured BAFs
or certain predicted BAFs. That previous designation of a high level of
concern for chemicals with BAF values greater than 1,000 provides
further support for the use of a BAF/BCF criterion of 1,000 for
determining whether a chemical should be classified as bioaccumulative
for purposes of section 313.
As with persistence, a number of organizations and internationally
negotiated agreements have set numerical criteria for bioaccumulation,
many of which have been developed through consensus processes. Some
Canadian projects, many dealing with the Great Lakes basin, have used a
BAF/BCF criterion of 5,000 or 1,000 or even 500 (Refs. 19, 64, and 65).
Under the NAFTA-CEC, final screening criteria are under review that use
a BAF/BCF criterion of 5,000 (Ref. 21) and the UNECE-LRTAP Protocol on
POPs also established a BAF/BCF criterion of 5,000 (Ref. 22). In
negotiation of the LRTAP Protocol, Germany proposed a BAF/BCF criterion
of 1,000 (Ref. 22). The Chemical Manufactures Association (CMA) in its
policy for identifying PBT chemicals (Ref. 23) established a BAF/BCF
criterion of 5,000.
EPA requests comment on its use of the 1,000 BCF/BAF criterion.
C. Technical Review of Persistence and Bioaccumulation Data and
Modeling Results
1. Persistence and bioaccumulation data. Table 1 below presents the
bioaccumulation and persistence data for the PBT chemicals being
considered in this proposed rule. More detailed discussions of the
sources of these data are provided in the support documents (Refs. 47
and 66) which commenters should consult for additional information.
EPA's approach to the collection of persistence data was to
identify reasonable ranges of half-lives for the principal
environmental media (air, water/sediment, soil). By identifying
reasonable ranges of half-lives for each chemical EPA was able to
consider the available data in determining whether a chemical's half-
life in a particular medium was above or below half-life criteria
selected for persistence in that medium. For example, if the reasonable
range of half-lives for a chemical in soil were from 3 to 5 months then
EPA could conclude that the chemical would exceed a 2-month soil half-
life criterion. In cases where the range of half-lives for
[[Page 706]]
a chemical bracketed a particular criterion, EPA determined whether the
available data supported the higher or lower end of the half-life
range. For example, when considering a 6-month half-life criteria, if a
chemical's half-lives in water range from 5 to 10 months, but the
higher value was based on a better study, then EPA believes that it is
reasonable to conclude that the chemical's half-life is greater than 6
months. EPA believes that this approach provided sufficient certainty
to determine, for purposes of section 313, whether the persistence of a
chemical in the principal environmental media was above or below a
particular criterion.
As discussed in Unit VII.A.1.a., EPA used a two-tiered approach in
considering the bioaccumulation and persistence potential for the
chemicals in this proposal. For persistence the two tiers are for
chemicals that persist in the environment in either water, sediment, or
soil with a half-life of 2 months or greater but less than 6 months and
for chemicals that persist in any of these media with a half-life of 6
months or greater. The two tiers for bioaccumulation are for BAFs and
BCFs of equal to or greater than 1,000 but less than 5,000 and equal to
or greater than 5,000. There are several chemical categories included
in Table 1 for which the persistence and bioaccumulation potential of
the members of the category vary. When considering the bioaccumulation
and persistence potential of chemical categories EPA reviewed the
individual bioaccumulation and persistence data for the category
members and determined which tier the entire chemical category should
be placed in. Some chemicals had half-life ranges that bracketed the
persistence tiers, for example, heptachlor has a soil half-life range
of 8 days to 4 years. In cases where the persistence data would
determine which, if either tier a chemical should be in, a
determination had to be made as to the most appropriate persistence
data to use. This was the case for five of the chemicals discussed in
the following paragraph. For these chemicals EPA considered the types
of studies supporting the half-life ranges and determined the most
appropriate tier for each chemical. The support document (Ref. 67)
contains a more detailed description of the rationale for EPA's
decision. Commenters should consult the docket for additional
information.
Table 1.--Persistence and Bioaccumulation Data
--------------------------------------------------------------------------------------------------------------------------------------------------------
Surface Water Half-
Chemical Category/Chemical Name CASRN BCF BAF Air Half-life life Soil Half-life
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dioxin/Dioxin-Like Compounds
Polychlorinated dibenzo-p-
dioxins
1,2,3,4,6,7,8-heptachlorodibenzo- 35822-46-9 1,466 12.2-4.2 hrs 20 yrs
p-dioxin
1,2,3,4,7,8-hexachlorodibenzo-p- 39227-28-6 5,176 12.4-2.7 hrs 20 yrs
dioxin
1,2,3,6,7,8-hexachlorodibenzo-p- 57653-85-7 3,981 12.4-2.7 hrs 20 yrs
dioxin
1,2,3,7,8,9-hexachlorodibenzo-p- 19408-74-3 1,426 12.4-2.7 hrs 20 yrs
dioxin
1,2,3,4,6,7,8,9- 3268-87-9 2,239 20.4-4.8 hrs 20 yrs
octachlorodibenzo-p-dioxin
1,2,3,7,8-pentachlorodibenzo-p- 40321-76-4 10,890 14.8-2.0 hrs 20 yrs
dioxin
2,3,7,8-tetrachlorodibenzo-p- 1746-01-6 5,755 9.6-1.2 hrs 20-1.5 yrs
dioxin
--------------------------------------------------------------------------------------------------------------------------------------------------------
Polychlorinated dibenzofurans
1,2,3,4,6,7,8- 67562-39-4 3,545 25.0-4.3 hrs 20 yrs
heptachlorodibenzofuran
1,2,3,4,7,8,9- 55673-89-7 3,545 25.0-4.3 hrs 20 yrs
heptachlorodibenzofuran
1,2,3,4,7,8- 70648-26-9 3,586 13.3-3 hrs 20 yrs
hexachlorodibenzofuran
1,2,3,6,7,8- 57117-44-9 3,586 13.3-3 hrs 20 yrs
hexachlorodibenzofuran
1,2,3,7,8,9- 72918-21-9 10,300 13.3-3 hrs 20 yrs
hexachlorodibenzofuran
2,3,4,6,7,8- 60851-34-5 3,586 13.3-3 hrs 20 yrs
hexachlorodibenzofuran
1,2,3,4,6,7,8,9- 39001-02-0 1,259 29.4-13.7 hrs 20 yrs
octachlorodibenzofuran
1,2,3,7,8- 57117-41-6 33,750 11.6-1.2 hrs 20 yrs
pentachlorodibenzofuran
2,3,4,7,8- 57117-31-4 42,500 11.6-1.2 hrs 20 yrs
pentachlorodibenzofuran
2,3,7,8-tetrachlorodibenzofuran 51207-31-9 2,042 11.5-2.1 hrs 20 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pesticides
Aldrin 309-00-2 3,715 10 hrs-1 hr 24 days1 9 yrs-291 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Chlordane 57-74-9 11,050 >6,000,0002 5 days-12 hrs 239 days 8-0.4 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dicofol 115-32-2 12,303 8 days-19 hrs 8.2 days-13 hrs 348-259 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Heptachlor 76-44-8 19,953 10.5 hrs-1 hr 129.4-23.1 hrs 4 yrs-8 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Isodrin 465-73-6 20,180 10 hrs-1 hr 5 yrs-180 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Methoxychlor 72-43-5 8,128 12 hrs-1 hr 15.2-5 days 136-81 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pendimethalin 40487-42-1 1,944 21-2 hrs 1300-54 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Toxaphene 8001-35-2 34,050 16 days-19 hrs 5 yrs-1 yr 11-1 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Trifluralin 1582-09-8 5,674 3.2-0.42 hrs 36.5-4.5 days1 394-99 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 707]]
Polycyclic Aromatic Compounds
Benzo(a)pyrene 50-32-8 912 2.4 hrs 17.3-5.4 yrs 14.6 yrs-151 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(b)fluoranthene 205-99-2 5,631 1.4 days-3.4 hrs 100 14.2 yrs-87 days
days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(r,s,t)pentaphene 189-55-9 26,280 13 hrs-1 hr 371-232 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(a)anthracene 56-55-3 800 13 hrs-1 hr 3-1.2 yrs 2.0 yrs-240 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
7,12-Dimethylbenz(a)anthracene 57-97-6 5,834 4-0.4 hrs 6 yrs-1 yr 28-20 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenzo(a,h)anthracene 53-70-3 31,440 13 hrs-1 hr 100 2 yrs-240 days
days
--------------------------------------------------------------------------------------------------------------------------------------------------------
3-Methylcholanthrene 56-49-5 17,510 3-0.3 hrs 3.8-1.7 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
7H-Dibenzo(c,g)carbazole 194-59-2 16,900 23-2 hrs >160 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(k)fluoranthene 207-08-9 10,090 12 hrs-1 hr 11 yrs-139 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(j)fluoranthene 205-82-3 10,090 12 hrs-1 hr 10.5 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenzo(a,e)pyrene 192-65-4 6,875 13 hrs-1 hr 371-232 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenzo(a,h)pyrene 189-64-4 26,280 13 hrs-1 hr 371-232 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Indeno(1,2,3-cd)pyrene 193-39-5 28,620 7.6-0.34 hrs 730-58 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenz(a,h)acridine 226-36-8 3,500 13 hrs-1 hr >160 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenz(a,j)acridine 224-42-0 18,470 23-2 hrs >160 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(g,h,i)perylene 191-24-2 25,420 10.0-0.31 hrs 100 1.8 yrs-173 days
days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenzo(a,e)fluoranthene 5385-75-1 26,280 10 hrs-1 hr 371-232 days3
--------------------------------------------------------------------------------------------------------------------------------------------------------
5-Methylchrysene 3697-24-3 9,388 5-0.5 hrs 3.8 yrs-79 days4 2.7 yrs-255 days4
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dibenzo(a,l)pyrene 191-30-0 6,875 13 hrs-1 hr 371-232 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(a)phenanthrene 218-01-9 800 13 hrs-1 hr 3.8 yrs-79 days 2.7 yrs-255 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
1-Nitropyrene 5522-43-0 908 4 days-10 hrs 44 yrs-16 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Benzo(j,k)fluorene 206-44-0 5,100 20-2 hrs 13 yrs-110 days
(fluoranthene)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Metals/Metal Compounds
Cobalt5 and Cobalt Compounds 7440-48-4 1-2,000,000 see footnote 5 see footnote 5 see footnote 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mercury5 and Mercury compounds 7439-97-6 7,000-36,000 see footnote 5 see footnote 5 see footnote 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vanadium5 and Vanadium compounds 7440-62-2 100,000-1,000,000 see footnote 5 see footnote 5 see footnote 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Polychlorinated Biphenyl 1336-36-3 >200,0002,6
(PCBs)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,3,4,4,5,5- 39635-31-9 4,922 191-19 days >56 days >5-3.92 yrs
heptachlorobiphenyl
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,3,4,4,5-hexachlorobiphenyl 38380-08-4 37,590 127-13 days >56 days >5-3.42 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,3,4,4,5-hexachlorobiphenyl 69782-90-7 37,590 114-11 days >56 days >5-3.42 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,4,4,5,5-hexachlorobiphenyl 52663-72-6 37,590 114-11 days >56 days >5-3.42 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 708]]
3,3,4,4,5,5-hexachlorobiphenyl 32774-16-6 73,840 88-9 days >56 days >5-3.42 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,3,4,4-pentachlorobiphenyl 32598-14-4 196,900 >134,000,0002 80-8 days >56 days 7.25-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,4,4,5-pentachlorobiphenyl 74472-37-0 196,900 67-7 days >56 days 7.25-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,4,4,5-pentachlorobiphenyl 31508-00-6 184,300 >141,000,0002 80-8 days >56 days 7.25-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,3,4,4,5-pentachlorobiphenyl 65510-44-3 196,900 50-5 days >56 days 7.25-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
3,3,4,4,5-pentachlorobiphenyl 57465-28-8 196,900 57-6 days >56 days 7.25-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
3,3,4,4-tetrachlorobiphenyl 32598-13-3 105,900 37-4 days >98 days 4.83-0.91 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Other Chemicals
Hexachlorobenzene 118-74-1 29,600-66,000 >2,500,0002 1,582-158 days 5.7-2.7 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Octachlorostyrene 29082-74-4 33,113 >117,000,0002 10 hrs-1 hr 5.7-2.7 yrs7
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pentachlorobenzene 608-93-5 8,318 >640,0002 460-46 days 194 days->22 yrs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tetrabromobisphenol A 79-94-7 780; 1,200; 3,200 9 days-1 day 84-48 days 44-179 days
--------------------------------------------------------------------------------------------------------------------------------------------------------
1The reported half-life data for water are suspected to include significant removal from the medium by processes other than degradation (e.g.,
volatilization).
2Values are for Piscivorous Fish.
3Since data could not be found for this chemical, the data for the dibenzopyrenes (192-65-4; 189-64-0; 191-30-0), which are structural analogues, was
used.
4Since data could not be found for this chemical, the data for benzo(a)phenanthrene (218-01-9), a structural analogue was used.
5The bioaccumulation potential for the parent metals is assumed to be equivalent to the associated metal compounds since in the environment the parent
metals may be converted to a metal compound. Since metals are not destroyed in the environment they persist longer than 6 months.
6Lowest value reported for a dichlorinated PCB.
7Since no data could be found for this chemical, the data for the structural analogues hexachlorobenzene (118-74-1) and pentachlorobenzene (608-93-5)
was used.
Benzo(j,k)fluorene (fluoranthene) has a soil half-life range of 110
days to 13 years, however the 13-year value is based on the results of
a field study and thus fluoranthene was determined to persist in soil
for greater than 6 months. As mentioned above, heptachlor has a soil
half-life range of 8 days to 4 years, however the 4-year value is based
on the results of a field study and thus heptachlor was also determined
to persist for greater than 6 months in soil. Tetrabromobisphenol A has
a surface water half-life range of 48 to 84 days and a soil half-life
range of 44 to 179 days. Based on a review of the grab sample studies,
it was determined that tetrabromobisphenol A should have a half-life in
water and soil of greater than 2 months but less than 6 months.
Trifluralin has a soil half-life range of 99 to 394 days, based on a
review of the field studies for trifluralin it was determined that it
should have a soil half-life of greater than 2 months but less than 6
months.
For a significant number of substances in several congeneric series
(polychlorinated dioxins; furans; PACs), half-lives were derived by
extrapolation from data for other substances in the series. This
approach is generally considered acceptable if appropriate allowance is
made for minor differences in molecular structure. No measured half-
life data for soil or water that met the standards for data
acceptability could be located for octachlorostyrene (CAS No. 29082-74-
4). Therefore, EPA used half-lives for the structural analogs
pentachlorobenzene (CAS No. 608-93-5) and hexachlorobenzene (CAS No.
118-74-1) for estimating half-lives for octachlorostyrene.
For the dioxin and dioxin-like compounds category the half-lives in
soil for all members is clearly greater than 6 months. For
bioaccumulation the members of this category have BCF values that range
from a low of 1,259 to a high of 42,500 with 6 chemicals over 5,000 and
with 6 chemicals between 3,500 and 5,000. Based on this data EPA
believes that, as a category, the dioxin and dioxin-like compounds
should be considered to have a BCF value greater than 5,000 since most
of the members are close to or well above 5,000. However, as discussed
in Unit VII.A.2., a special reporting threshold is required for this
category, and therefore the BCF value for the category was not a major
factor in selecting the proposed reporting threshold.
For the members of the polycyclic aromatic compounds (PACs)
category, all but a few had soil or surface water half-lives well in
excess of 6 months. The BCF values for the category ranged from a low
of 800 to a high of 31,440 with 15 of the 20 category members having
BCF values greater than 5,000. Based on this data EPA believes that, as
a category, the polycyclic aromatic compounds should be considered to
have a BCF value greater than 5,000. As an alternative, the category
could be separated into two categories with appropriate reporting
thresholds for each category. However, this would
[[Page 709]]
tend to be more burdensome since some facilities might have to file two
reports and because it would require further speciation of the members
of the category.
EPA requests comment on this alternative proposal to create two
PACs categories.
The section 313 listing for PCBs is not a category listing but its
CAS number covers all PCBs making it the equivalent of a category of
chemicals. For the PCBs in Table 1 and for additional PCBs listed in
the support document (Ref. 66), the soil half-lives are greater than 6
months, the reported BAF values are well above 5,000 (Table 1 and Ref.
47), and, with one exception, the BCF values for those PCBs in Table 1
are above 5,000. For the one exception, 2,3,3',4,4',5,5'-
heptachlorobiphenyl, the estimated BCF is 4,922 which, considering the
data for the other PCBs, EPA believes is sufficiently close to 5,000
for this chemical to be considered to have a BCF of 5,000. Based on the
available data EPA believes that all members covered by the section 313
PCBs listing should be considered to have soil half-lives greater than
6 months and BAF/BCF values greater than 5,000.
For metals and metal compounds, although a metal or metal compound
can be converted to another metal compound, the metal is not destroyed
in the environment. Thus, metals obviously persist for greater than 6
months. As for bioaccumulation potential, the BCF values are reported
as ranges of values with extremely high values at the upper end of the
range. For purposes of section 313 reporting, EPA considered mercury
and mercury compounds to have BCF values greater than 5,000. During the
inter-agency review process, some reviewers raised questions about the
adequacy of the studies that were used to make the BCF determination
for cobalt and cobalt compounds. EPA specifically requests comment on
the adequacy of these studies for determining bioaccumulation potential
for cobalt and cobalt compounds. At this time cobalt and cobalt
compounds do not appear on the proposed regulatory text list of PBT
chemicals with lowered reporting thresholds. However, depending on
comments received, EPA may add cobalt and cobalt compounds to that list
in the final rule. As discussed in Unit IV.C.7. of this preamble, EPA
is also requesting comment on the sufficiency of the bioaccumulation
data for vanadium and vanadium compounds.
EPA requests comment on its evaluation of persistence and
bioaccumulation for each of the chemicals included in this rulemaking.
2. Epoxidation of certain pesticides. Epoxidation is one of the
major mechanisms of microbial metabolism of the cyclodiene pesticides
including aldrin, heptachlor, and isodrin (Ref. 68). Aldrin is
epoxidized to dieldrin (Ref. 69); isodrin is epoxidized to endrin; and
heptachlor is converted to heptachlor epoxide (Ref. 70). These
transformations are common and have been reported to occur in microbes,
crustaceans, insects, fish, mammals, and birds (Refs. 71, 72, 73 and
74). Epoxides of heptachlor and aldrin are both insecticidal, and thus
their biological activity is prolonged in soil.
The persistence and bioaccumulation data for the epoxides endrin,
dieldrin, and heptachlor epoxide are included in the support documents
for persistence and bioaccumulation (Refs. 47 and 66). The persistence
and bioaccumulation data for endrin include 3 to 7 hours in air,
greater than 112 days in surface water, and 333 to 4,300 days in soil
with a BCF value of 4,591. The persistence and bioaccumulation data for
dieldrin include 3 to 30 days in air, greater than 56 days in surface
water, and 175 to 1,080 days in soil with a BCF value of 4,467. The
persistence and bioaccumulation data for heptachlor epoxide include 6
to 60 hours in air and 33 to 522 days in soil with a BCF value of
14,454. Thus all of these compounds persist in at least one medium and
are highly bioaccumulative. Regarding the toxicity of these epoxides,
EPA's Integrated Risk Information System (IRIS) indicates that dieldrin
and heptachlor epoxide have been classified by EPA as Group B2
carcinogens (i.e., they are probable human carcinogens) and that endrin
caused convulsions and liver toxicity in a 2-year feeding study in dogs
(Ref. 75).
The epoxidation of the parent compounds aldrin, heptachlor, and
isodrin is important in light of the fact that the epoxides produced
are persistent, bioaccumulative, and toxic. Therefore, in the medium
that the epoxide is formed the parent compounds are being transformed
into another toxic chemical. This means that the half-lives of the
parent compounds in the epoxidizing medium may underestimate the
concern for the parent compounds since they are converted to another
toxic chemical that also persists and bioaccumulates. This could be
characterized as extending the persistence of a toxic chemical in that
media. Often these compounds are considered together and listed as
aldrin/dieldrin, isodrin/endrin, and heptachlor/heptachlor epoxide.
The rates of transformation from the parent chemical to the epoxide
have not been well-characterized in all relevant media. However, it is
important to consider that transformation of these parent compounds to
their epoxides, regardless of the rate, results in the formation of
products that are of concern for their persistence, bioaccumulation
potential, and toxicity.
3. Multimedia modeling results. The results of the modified version
of the EQC multimedia modeling runs were presented as ``total
persistence half-lives'' (Ref. 76). The EQC model defines ``overall
persistence'' or ``residence time'' as the ratio of the amount of
chemical present in the evaluative environment at steady state to the
total rate of loss. Total persistence is also expressed as the
reciprocal of the total removal rate constant. The total persistence
half-lives are calculated by multiplying the overall persistence by ln
2.
The use of the medium (i.e., the midpoint of the half-life range)
and high half-life values for each medium resulted in overall
persistence half-lives of greater than 2 months for all chemicals in
Table 1 of this unit except 7,12-dimethylbenz(a)anthracene, heptachlor,
methoxychlor, and trifluralin.
7,12-Dimethylbenz(a)anthracene was modeled using half-life ranges
of 24 minutes to 4 hours for air, 1 to 6 years for water and sediment,
and 20 to 28 days for soil. The results of the modified EQC model
suggest that at steady state, sufficient quantities of this chemical
will volatilize to the atmosphere and undergo hydroxy radical
oxidation, and partition to soils with subsequent biodegradation that
the overall environmental persistence will be 1 month.
Half-life ranges used for heptachlor were 1 to 10.5 hours for air,
23 hours to 5 days for water, and 8 days to 4 years for soil and
sediment. Half-life ranges used for methoxychlor were 1 to 12 hours for
air, 5 to 15.2 days for water and sediment, and 81 to 136 days for
soil. Trifluralin was modeled using half-life ranges of 25 minutes to
3.2 hours for air, and 99 to 394 days for water, soil, and sediment.
The modified EQC model predicts that at steady state, sufficient
quantities of these chemicals will volatilize to the atmosphere and
undergo hydroxy radical oxidation that the overall environmental
persistence will be 0.03 months for heptachlor, 0.7 months for
methoxychlor, and 0.6 months for trifluralin.
It should be noted that all of these compounds are expected to
enter the atmosphere associated with particulate
[[Page 710]]
matter or in particulate form. The method used for the estimation of
hydroxy radical oxidation half-lives is applicable to chemicals in the
vapor phase. Rates of oxidation for chemicals in particulate form or
associated with particulate matter may be overestimated, but the extent
is unknown and thus there is some question as to the accuracy of the
data used in the modeling. Also, since sediment half-lives were not
available for these chemicals, the sediment half-lives used in the
modeling were that same as the surface water half-lives. Since sediment
half-lives are usually longer than surface water half-lives this may
result in an underestimation of the ``total persistence half-lives''
generated by the modified EQC model. In fact, when modeled using
sediment half-lives four times that of the surface water half-lives,
the ``total persistence half-lives' for these chemicals did increase
(Ref. 76). For heptachlor there is also the issue of the epoxidation to
heptachlor epoxide and how that transformation affects the overall
persistence of heptachlor/heptachlor epoxide. Also, since 7,12-
dimethylbenz(a)anthracene is a member of the polycyclic aromatic
compounds category EPA believes that it would be best not to separate
it out from the other 20 carcinogenic members of the category.
As stated in section A.5. of this unit, EPA intends to only use
multimedia modeling results to override the medium-specific persistence
data if all model inputs are judged to be accurate. Because of the
uncertainties associated with the air half-lives for these chemicals
and the lack of data on sediment half-lives, which could affect the
modified EQC modeling results, EPA does not believe that the modeling
results should be used to override the medium-specific persistence data
for these chemicals.
EPA requests comments on how the results of the modified EQC
multimedia modeling for these chemicals should affect their status as
PBT chemicals for purposes of EPCRA section 313.
VI. Modifications to Proposed Dioxin and Dioxin-Like Compounds
Category
In response to a petition from Communities For A Better
Environment, EPA issued a proposed rule (62 FR 24887) to add a category
of dioxin and dioxin-like compounds to the EPCRA section 313 list of
toxic chemicals. As part of that action, EPA proposed to move 11 co-
planar PCBs from their listing under CAS number 1336-36-3 to a dioxin
and dioxin-like compounds category. To accomplish this, EPA proposed to
add a qualifier to the current PCB listing so that it would read
``polychlorinated biphenyls (PCBs) (excluding those PCBs listed under
the dioxin and dioxin-like compounds category)'' and to list each of
the 11 PCBs by name and CAS number in the proposed dioxin and dioxin-
like compounds category. As discussed in Unit V.C. of this preamble,
EPA has determined that all PCBs persist and bioaccumulate. Since PCBs
persist and bioaccumulate, EPA believes that they should be subject to
lower reporting thresholds, and thus there is no need to move the 11
co-planar PCBs to the proposed dioxin and dioxin-like compounds
category. Therefore, EPA has decided to withdraw its proposal to modify
the current listing for PCBs and instead proposes to lower the
reporting thresholds for the current PCB listing which covers all PCBs.
EPA believes that, since all PCBs persist and bioaccumulate, it is
appropriate to lower the reporting threshold for this class of
chemicals and that this proposal is less burdensome than requiring
separate reporting on the dioxin-like PCBs as part of the proposed
dioxin and dioxin-like compounds category. Because of this change, the
proposed dioxin and dioxin-like compounds category would include only
the 7 polychlorinated dibenzo-p-dioxins and the 10 polychlorinated
dibenzofurans identified in the proposed rule.
EPA requests comment on its withdrawal of the proposal to modify
the current listing for PCBs by adding the qualifier described above.
In addition to the above modification to the dioxin and dioxin-like
compounds category, EPA is proposing to add an activity qualifier to
the category that limits reporting to facilities that manufacture these
chemicals. These dioxin and dioxin-like compounds are ubiquitous in the
environment and thus under the very low reporting thresholds necessary
to get reports from any sources (see discussion in Unit VII.A.2. of
this preamble), facilities that process raw materials would be required
to report simply because the raw material contains background levels of
these chemicals. In order to focus reporting on those facilities that
actually add to the environmental loading of these chemicals, EPA is
proposing to add the activity qualifier ``manufacture only'' to the
category. This will mean that only those dioxin and dioxin-like
compounds that are manufactured at the facility, including those
coincidentally manufactured, will be the subject of reporting under
section 313. This will not only focus attention on activities that add
to the loading of these chemicals in the environment but it also
significantly reduces the reporting burden for industry that would
result without the activity qualifier.
EPA requests comment on this proposed qualifier for the dioxin and
dioxin-like compounds category.
VII. Proposed Changes to Reporting Requirements for PBT Chemicals
A. Changes to Reporting Thresholds
1. Selection of lower reporting thresholds. In selecting potential
lower reporting thresholds for PBT chemicals, EPA considered not only
their persistence and bioaccumulation but also the potential burden
that might be imposed on the regulated community. Each of these
important considerations is discussed below.
a. Persistence and bioaccumulation. Because all PBT chemicals
persist and bioaccumulate in the environment, they have the potential
to pose human health and environmental risks over a longer period of
time. Thus, even small amounts that enter the environment can lead to
elevated concentrations in the environment and in organisms which can
result in adverse effects on human health and the environment. The
nature of PBT chemicals indicates that small quantities of such
chemicals are of concern, which provides strong support for setting
lower reporting thresholds than the current section 313 thresholds of
25,000 and 10,000 pounds. For determining how low reporting thresholds
should be set for these chemicals, EPA has adopted a two-tiered
approach. This approach recognizes that toxic chemicals that have very
high persistence and bioaccumulation potentials (e.g., chemicals with
half-lives of 6 months or more and BAF/BCF values of 5,000 or more),
like those that have been widely recognized as PBT chemicals, are of
greatest concern. EPA believes that for toxic chemicals that are highly
persistent and bioaccumulative, any release of the toxic chemical can
result in elevated concentrations in the environment and organisms
because of their very high persistence and bioaccumulation potentials.
As a result, consideration of persistence and bioaccumulation alone
would lead EPA to set a reporting threshold for the subset of highly
persistent bioaccumulative chemicals that approaches zero in order to
provide relevant data to communities. Thus, EPA believes that it is
appropriate to set a low threshold for toxic chemicals that persist and
bioaccumulate and to set a lower threshold for toxic chemical that are
highly persistent and
[[Page 711]]
bioaccumulative. EPA has made this distinction between persistent
bioaccumulative chemicals and highly persistent bioaccumulative
chemicals by proposing to set lower reporting thresholds based on two
levels of persistence and bioaccumulation potential. The two levels are
for those PBT chemicals included in this rule that persist in the
environment with a half-life of 2 months or greater but less than 6
months and that have BAF or BCF values of 1,000 or greater but less
than 5,000 (the 2-month and 1,000 group) and for those chemicals that
persist in the environment with a half-life of 6 months or greater and
that have BAF or BCF values of 5,000 or greater (the 6-month and 5,000
group). EPA believes that based solely on the degree of persistence and
bioaccumulation it would be appropriate to set section 313 manufacture,
process, and otherwise use thresholds to 10 pounds for chemicals
meeting the 2- to 6-month and 1,000 to 5,000 criteria and to 1 pound
for chemicals meeting both the 6-month or greater and 5,000 or greater
criteria. One exception to this is the reporting threshold for the
dioxin and dioxin-like compounds category. See Unit VII.A.3. below.
EPA believes that it is appropriate to set two thresholds based on
the degree of persistence and bioaccumulation of the chemicals because
chemicals with a half-life of 6 months or greater and a BAF/BCF of
5,000 or greater have a higher exposure potential than chemicals with a
half-life of 2 months or greater and a BAF/BCF of 1,000. EPA believes
that communities have a greater right-to-know about chemicals which can
reasonably be anticipated to be present in the community at higher
levels. This greater exposure potential is illustrated in the examples
below.
More of a given quantity of a chemical with a half-life of 6 months
will exist in the environment 1 year after release than of a given
quantity of a chemical with a half-life of 2 months. Specifically, on
January 1, a facility releases 100 pounds of a chemical with a half-
life of 6 months. On July 1, 50 pounds will remain in the environment;
on December 31, 25 pounds will remain in the environment. On January 1,
the same facility releases 100 pounds of a chemical with a half-life of
2 months. On July 1, 12.5 pounds will remain in the environment; on
December 31, 1.6 pounds of the chemical will remain in the environment.
The chemical with the half-life of 6 months will result in long-term
elevated quantities of the chemical in the environment. Further,
releases of persistent toxic chemicals that occur more frequently than
once a year can rapidly result in large increases in the amounts of the
chemicals present at any one time in the environment because the
environment does not have sufficient time to remove these chemicals
through degradation. This example is somewhat oversimplified because a
chemical's biodegradation rate is dependent on so many environmental
conditions and may fluctuate during the year depending on changes in
environmental conditions. However, all conditions being equal, the
chemical with the longer half-life will be present in the environment
for a longer period of time.
The increased exposure potential also applies to chemicals with
different BCFs. The identical amount of two different chemicals,
chemical A with a BCF of 1,000 to fish and chemical B with a fish BCF
of 5,000 will result in different exposures to fish that consume other
organisms lower in the food chain, that have also been exposed to these
chemicals. For example, organisms that consume the fish exposed to
chemical B will usually be exposed to greater quantities of the
chemical than organisms that consume the fish that was exposed to
chemical A, assuming identical feeding rates and other conditions. Due
to concerns for its higher accumulation potential, a lower threshold
will be set for Chemical B.
b. Consideration of burden in threshold selection. As discussed
above, in determining the appropriate reporting thresholds to propose
for PBT chemicals, EPA started with the premise that low or very low
reporting thresholds may be appropriate for this class of chemicals
based on their persistence and bioaccumulation potentials only. EPA
then considered the burden that would be imposed by four sets of
reporting thresholds. The thresholds considered were: (1) the 1 and 10
pound thresholds discussed above; (2) 10 pounds for chemicals in the 6-
month and 5,000 group with 100 pounds for chemicals in the 2-month and
1,000 group; (3) 100 pounds for chemicals in the 6-month and 5,000
group with 1,000 pounds for chemicals in the 2-month and 1,000 group;
and (4) 1,000 pounds for both groups of chemicals. For each set of
thresholds EPA estimated the number of facilities that might be
required to report for the various PBT chemicals (see Table 4 in Unit
X.E.4. of this preamble). Based on the potential burdens, EPA believes
it is appropriate to lower the reporting thresholds to a level that
would capture significantly more information about PBT chemicals than
current thresholds but that would not be unduly burdensome on industry.
Therefore, EPA is proposing to lower the manufacture, process, and
otherwise use thresholds to 100 pounds for toxic chemicals meeting the
2- to 6-month and 1,000 to 5,000 criteria and to 10 pounds for toxic
chemicals meeting the 6-month or greater and 5,000 or greater criteria.
EPA requests comment on its consideration of industry burden in
establishing lower reporting thresholds, including the extent to which
burden should be considered in EPA's decision. EPA requests comment on
whether the Agency should lower the reporting thresholds to 1 pound for
the 6-month and 5,000 group and 10 pounds for the 2-month and 1,000
group rather than the 10 and 100 pound reporting thresholds proposed in
this document. EPA requests comment on whether there are any policy
reasons for selecting the 1 and 10 pound reporting thresholds rather
than the 10 and 100 pound reporting thresholds. Such policy reasons
could include the fact that the 10 pound reporting threshold for the
chemicals in the 6-month and 5,000 group, i.e., the chemicals that are
highly persistent and bioaccumulative, may not capture all releases
that are of concern to local communities. Alternatively, EPA also seeks
comment on reasons for selecting reporting thresholds of 100 pounds and
1,000 pounds.
For purposes of this rulemaking the Agency has focused on
persistence and bioaccumulation as a basis for setting lower reporting
thresholds. EPA believes it has discretion to use other factors as part
of its basis for modifying the reporting thresholds. For example, EPA
could consider biomagnification, relative toxicity, persistence only or
bioaccumulation only. EPA requests comment on these factors and on
other factors that the Agency could consider in selecting reporting
thresholds in the future.
c. Relationship of TRI reporting thresholds to other statutory
thresholds. For purposes of establishing EPCRA section 313 reporting
thresholds, Congress has expressed a clear intent to obtain reporting
on a substantial majority of total releases of the chemical at all
facilities subject to the requirements of the section, and to assure
that this information is reported to EPA and the states and provided to
the user community. In this action, by proposing to lower the reporting
thresholds for certain persistent and bioaccumulative chemicals listed
on EPCRA section 313, EPA is working to assure that communities are
provided with data on these toxic chemicals, which are frequently
manufactured, processed, or otherwise used in
[[Page 712]]
quantities well below the existing reporting thresholds of 25,000
pounds and 10,000 pounds and consequently are not reported to EPA and
the states. In choosing the proposed EPCRA section 313 thresholds for
these PBT chemicals EPA took into consideration a number of factors
including small business impacts, overall reporting burden, and report
generation in addition to utility of the information. It has been EPA's
goal, under the EPCRA section 313 program, to maintain a balance
between community right-to-know and overall reporting burden for the
affected industry.
EPCRA section 313 provides one of several authorities through which
EPA collects data. Each of these authorities has different criteria and
different purposes. Many are aimed at supporting environmental
decisionmaking and standard setting with community involvement in these
processes. The thresholds established under EPCRA section 313 are
designed to meet the statutory requirements of the Act as well as the
overarching goal of informing the public about chemical releases and
other waste management practices in their communities. Other EPA
statutes such as the Clean Water Act (CWA), the Clean Air Act (CAA),
and Resource Conservation and Recovery Act (RCRA) also have information
collection provisions, whose criteria, coverage, scope and purpose may
be different from that of EPCRA section 313. The thresholds proposed
here, for purposes of EPCRA section 313, should not be construed to
limit or expand the data collection goals or authorities of other EPA
programs.
For example, the Office of Air and Radiation (OAR) may require any
sector to provide data as necessary to support the further
implementation of the CAA. Under section 114 (a) of the CAA, the
Administrator of EPA has the authority to write letters requesting and
requiring the submission of data from CAA covered sources. A CAA data
collection, may in part, be focused on the need to address questions
about a specific industry sector or a particular type of emission. In
such an instance, EPA may decide to base its information request on
different facility sizes, thresholds of release, or burden of
reporting. EPA has submitted an Information Collection Request to the
Office of Management and Budget for an information collection effort
under Section 114 of the CAA that would require all coal fired power
plants over 25 MW to submit to EPA the results of analyses (coal
sampling and for a representative sample of plants stack testing). This
would allow a calculation of facility-specific mercury emissions for
each coal fired plant. Unlike this proposed rule, the information
collection effort under the CAA would require that analysis be
performed that power plant operators may not be currently performing
and thus would allow emissions estimates that may be more precise than
those that would otherwise be provided under this proposed rule.
2. Special reporting threshold for dioxin and dioxin-like
compounds. Based on the persistence and bioaccumulation data for the
category of dioxin and dioxin-like compounds that EPA has proposed for
addition to section 313, they would ordinarily be included in the 6-
month and 5,000 group. However, this category of chemicals poses unique
problems with regard to setting section 313 reporting thresholds. These
chemicals are generally produced in extremely small amounts compared to
other section 313 chemicals. Thus, in order to capture any release data
at all, a much lower reporting threshold than those proposed above is
required. EPA has received numerous comments suggesting that the
reporting threshold for this category be set at zero. However, EPA does
not believe that a zero threshold would be practical. Attempting to
require facilities to determine if they manufacture, process, or
otherwise use any amount whatsoever of these chemicals would be
extremely burdensome and perhaps technically impossible. Without an
actual numerical reporting threshold, many facilities might report some
amount of these chemicals just to make sure that they are in
compliance. This could lead to misleading and inaccurate data on the
actual sources of these chemicals as well as imposing increased burden
on reporting facilities. EPA believes that rather than setting a zero
reporting threshold it would be better to set a very low threshold that
provides facilities with a clear indicator of when they are required to
report. EPA believes that a manufacture, process, or otherwise use
reporting threshold of 0.1 gram for the category would capture the
majority of releases likely to come from section 313 facilities. Since
the current section 313 reporting instructions and forms do not require
the reporting of amounts less than 1 pound, they would be modified to
allow for the reporting of amounts less than 1 pound. EPA intends to
develop reporting guidance for industries that may fall within this
reporting category.
The guidance developed will be consistent with the methods and
procedures that EPA has developed for determining if dioxin and dioxin-
like compounds are present in various industrial processes, including
Method 23 (Ref. 77) developed for electric utilities. In developing the
reporting guidance for the dioxin and dioxin-like compounds category
EPA will work with interested parties to provide the best possible
guidance for reporting facilities.
EPA requests comment on whether reporting at this level would
provide meaningful information to communities.
In addition to the proposed lower reporting threshold for the
dioxin and dioxin-like compounds category, EPA is considering an
alternative way of reporting release and other waste management data
for this category. The toxicity of dioxin-like compounds is often
expressed in terms of toxicity equivalents or TEQs. TEQs are determined
by summing the products of multiplying concentrations of individual
dioxin-like compounds times the corresponding toxicity equivalence
factor (TEF) for that compound. Because of their common mechanism of
action, TEFs have been established for dioxin-like compounds. TEFs
represent order of magnitude estimates of the relative potency of
dioxin-like compounds compared to 2,3,7,8-tetrachloro-p-dioxin (i.e.,
dioxin), and have been considered by EPA and the international
scientific community to be a valid and scientifically sound approach
for assessing the likely health hazard of dioxin-like compounds (Ref.
78). TEFs for the dioxin-like compounds included in the proposed dioxin
and dioxin-like compounds category range from 0.5 to 0.001. Reporting
release and other waste management information as a sum of all of the
grams of the individual members of the dioxin and dioxin-like compounds
category would not provide any information to determine the TEQs unless
the distribution of the dioxin and dioxin-like compounds were otherwise
known for any reported quantity. Without the distribution data the
public would not be able to determine the relative hazard associated
with such release and other waste management information. In addition,
Agency reports concerning dioxin and dioxin-like compounds commonly
describe dioxin emissions in terms of TEQs. Therefore, as an
alternative to reporting release and other waste management data for
the dioxin and dioxin-like compounds category as a grams-only sum of
all members, EPA is proposing to have this information reported in
terms of grams of TEQs. However, there are three significant
disadvantages to reporting in TEQs. First, revisions in TEF factors for
individual dioxin-like compounds in future years would require changes
to
[[Page 713]]
the calculations in the reported release and other waste management
quantities, thus making year to year comparisons more difficult, unless
the particular dioxin-like compounds are identified. Second, some
facilities may not be able to report in TEQs, since, although they may
be able to estimate a mass quantity for the category as a whole, they
may not have enough information to estimate the relative distribution
of all category members. Third, TEQ reporting would be different from
all other TRI reporting, which is mass-based, and may cause additional
confusion. However, if these problems can be resolved then reporting in
terms of TEQs may provide more useful data to the public. Under this
alternative method of reporting release and other waste management
information, reporting thresholds would still be based on the total
absolute weight of the members of the dioxin and dioxin-like compounds
category, not on the equivalent weight of TEQs.
EPA requests comments on this alternative method of reporting
release and waste management information for the dioxin and dioxin-like
compounds category.
3. Proposed reporting thresholds by chemical/category. Table 2
contains the proposed section 313 reporting thresholds for each of the
PBT chemicals included in this proposed rule. For purposes of section
313 reporting, threshold determinations for chemical categories must be
based on the total of all toxic chemicals in the category (see 40 CFR
372.25(d)). For example, a facility that manufactures three members of
a toxic chemical category would count the total amount of all three
toxic chemicals manufactured towards the manufacturing threshold for
that category. One report is filed for the category and all releases
are reported on one Form R (the form for filing reports under EPCRA
section 313 and PPA section 6607).
Table 2.--Reporting Thresholds for EPCRA Section 313 Listed PBT
Chemicals
------------------------------------------------------------------------
Section 313
Reporting
Chemical Name or Chemical CASRN Threshold (in
Category Name pounds unless
noted otherwise)
------------------------------------------------------------------------
Aldrin 309-00-2 100
------------------------------------------------------------------------
Benzo(g,h,i)perylene 191-24-2 10
------------------------------------------------------------------------
Chlordane 57-74-9 10
------------------------------------------------------------------------
Dicofol 115-32-2 10
------------------------------------------------------------------------
Dioxin and dioxin-like compounds NA 0.1 grams
category (manufacture only)
------------------------------------------------------------------------
Heptachlor 76-44-8 10
------------------------------------------------------------------------
Hexachlorobenzene 118-74-1 10
------------------------------------------------------------------------
Isodrin 465-73-6 10
------------------------------------------------------------------------
Methoxychlor 72-43-5 100
------------------------------------------------------------------------
Octachlorostyrene 29082-74-4 10
------------------------------------------------------------------------
Pendimethalin 40487-42-1 100
------------------------------------------------------------------------
Pentachlorobenzene 608-93-5 10
------------------------------------------------------------------------
Polycyclic aromatic compounds NA 10
category
------------------------------------------------------------------------
Polychlorinated biphenyl (PCBs) 1336-36-3 10
------------------------------------------------------------------------
Tetrabromobisphenol A 79-94-7 100
------------------------------------------------------------------------
Toxaphene 8001-35-2 10
------------------------------------------------------------------------
Trifluralin 1582-09-8 100
------------------------------------------------------------------------
Mercury 7439-97-6 10
------------------------------------------------------------------------
Mercury compounds NA 10
------------------------------------------------------------------------
------------------------------------------------------------------------
B. Proposed Changes to the Use of the de minimis Exemption
As part of the final rule implementing the reporting provisions of
EPCRA section 313 (53 FR 4500, February 16, 1988), EPA adopted a
limited de minimis exemption for listed toxic chemicals in mixtures.
The de minimis exemption allows facilities to disregard certain
concentrations of chemicals in mixtures or other trade name products
they import, process, or otherwise use in making threshold calculations
and release and other waste management determinations for section 313
reporting. This exemption does not apply to the manufacture of a toxic
chemical unless the toxic chemical is manufactured as an impurity or is
imported.
EPA adopted this exemption in response to comments requesting some
type of concentration limitation for listed toxic chemicals in mixtures
or other trade name products as a burden reducing measure. Commenters
contended that it would be extremely
[[Page 714]]
burdensome for suppliers, processors, and other users of mixtures or
trade name products to have to account for quantities below a de
minimis level. Most of these commenters requested that EPA adopt a de
minimis concentration limitation consistent with the Occupational
Safety and Health Administration (OSHA) Hazard Communication Standard
(HCS) requirement. The HCS provides that a supplier does not have to
list a ``hazardous chemical'' component in a mixture if that chemical
comprises less than 1.0% of the mixture or 0.1% where the chemical is a
carcinogen as defined in 29 CFR 1910.1200(d)(4). OSHA chose the 1% and
0.1% limits because the Agency believed that they generally appeared to
be protective of workers and were considered reasonable by a number of
commenters.
EPA adopted the de minimis exemption primarily as a means of
reducing burden associated with the new (at the time) EPCRA section 313
reporting requirements. The Agency chose the HCS levels because: (1)
They were consistent with the existing OSHA requirements for developing
Material Safety Data Sheet (MSDS) information and with other
requirements under EPCRA sections 311 and 312; (2) suppliers of
products were familiar with these levels; (3) for the first 2 years of
reporting, users of these mixtures are only likely to be able to rely
on the product MSDS for information about the content and percentage
composition of covered toxic chemicals in these products; and (4) EPA
did not expect that the processing and otherwise use of toxic chemicals
at less than the de minimis concentration in mixtures would, in most
instances, contribute significantly to the threshold determinations or
releases of listed toxic chemicals from any given facility.
When determining whether the de minimis exemption applies to a
listed toxic chemical, the facility must consider only the
concentration of the toxic chemical in mixtures and trade name products
in process streams in which the toxic chemical is involved in a
reportable activity. If the toxic chemical in a process stream is
manufactured as an impurity, imported, processed, or otherwise used and
is below the appropriate de minimis concentration level, then the
quantity of the toxic chemical in that process stream does not have to
be applied to threshold determinations nor included in release or other
waste management determinations. If a toxic chemical in a process
stream is below the appropriate de minimis level, all releases and
other waste management activities associated with the toxic chemical in
that stream are exempt from EPCRA section 313 reporting. It is possible
to meet an activity (e.g., processing) threshold for a toxic chemical
on a facility-wide basis, but not be required to calculate releases or
other waste management quantities associated with a particular process
because that process involves only mixtures or trade name products
containing the toxic chemical below the de minimis level.
As stated above, the intent of the de minimis exemption was
primarily burden reduction. The de minimis exemption was not intended
to be a general small quantity exemption, but rather an exemption based
on the limited information likely to be readily available to facilities
newly affected by EPCRA section 313. EPA did not expect in 1988 that
``the processing and [otherwise] use of mixtures containing less than
the de minimis concentration would, in most instances, contribute
significantly to the threshold determinations or releases of listed
toxic chemicals from any given facility'' (53 FR 4509). However, given
10 years of experience with the program, EPA believes that there are
many instances where a PBT chemical may exist in a mixture at a
concentration below the 1% (or 0.1% for OSHA carcinogens) de minimis
but where the manufacture, process, or otherwise use of the PBT
chemical in that mixture would otherwise contribute significantly to or
exceed the reporting thresholds proposed in this rule.
For example, a raw material is processed that contains less than
the de minimis level of a PBT chemical. The quantity of raw material
processed results in significantly more than the threshold quantity of
the PBT chemical being processed. Also, during the processing of the
PBT chemical, its concentration in the process stream remains below the
de minimis level. However, the concentration of the PBT chemical in the
wastestream that results from that processing activity is above the de
minimis concentration level for that PBT chemical and the wastestream
containing that PBT chemical is released to the land. In this example,
because the concentration of the PBT chemical in the process stream is
below the de minimis concentration, the de minimis exemption can be
taken. As a result, (1) The quantities processed do not have to be
applied to the processing threshold for that PBT chemical at the
facility, and (2) quantities of the PBT chemical that are released or
otherwise managed as waste as a result of this specific processing
activity are exempt from release and other waste management
determinations. The exemption applies even though the PBT chemical is
concentrated above the de minimis level in the wastestream. This
information would not be included in that facility's Form R.
In addition, EPA believes that the information available to the
typical EPCRA section 313 reporter is generally greater than it was 10
years ago. Since 1987, the Air Pollution Emission Factors (AP-42)
guidance document has been repeatedly updated and expanded. For example
several new sections were added in 1996, including a section specific
to electroplating. In the early 1990s, the Factor Information Retrieval
data base (FIRE) was developed. EPA has developed several additional
guidance documents and software programs, including Air CHIEF CD-ROM,
TANKS, CHEMDAT8, and WATER8 (this is an analytical model for estimating
chemical-specific air emissions from wastewater collection and
treatment systems) to aid facilities in estimating releases. Facilities
also have access to guidance from trade associations, e.g., National
Council of the Paper Industry for Air and Stream Improvement, Inc.
(NCASI).
Given that there may be significant releases of PBT chemicals in
mixtures when the PBT chemicals exist below the de minimis limit and
that even minimal releases of persistent bioaccumulative chemicals may
result in elevated concentrations in the environment or in an organism
that reasonably can be anticipated to result in significant adverse
effects, EPA believes that allowing facilities to continue to take the
de minimis exemption for PBT chemicals would deprive communities of
important information on PBT chemicals. While these chemicals may exist
in mixtures at below the de minimis levels they will concentrate in the
environment and in organisms. Further, many of the PBT chemicals
addressed in today's action have been shown to cause adverse effects at
concentrations far less than the de minimis levels. For example,
dioxins have been shown to cause adverse effects at concentration
levels in the parts per trillion. Thus, because PBT chemicals can cause
adverse effects at concentrations well below de minimis levels, EPA
believes that the de minimis principle may no longer apply. See
Environmental Defense Fund v. EPA, 82 F.2d 451, 466 (D.C. Cir. 1996);
Alabama Power Co. V. Costle, 636 F.2d 323, 360 (D.C. Cir 1979). In
addition, for the reasons articulated above, EPA is concerned about
whether other similar regulatory exemptions continue to be
[[Page 715]]
supportable for PBT chemicals. See e.g., 40 CFR 372.38(c).
Further, EPA believes that lowering the reporting thresholds for
these chemicals while leaving the de minimis exemption in place may
result in very limited reporting and undermine the very purpose of this
action. Without a concomitant change in the de minimis exemption,
lowering the reporting thresholds would not increase reporting for some
of the PBT chemicals because much of their releases would be exempt due
to their generally low concentrations in mixtures or other trade name
products that are processed or otherwise used. The facility may exceed
the reporting threshold based on some processes that involve the PBT
chemical in a mixture where the PBT chemical is above the de minimis
level or on activities for which the de minimis exemption is not
applicable. However, EPA expects there will be significant numbers of
activities that occur for which the de minimis exemption could
otherwise be taken. All releases and other waste management activities
associated with these activities would therefore be exempt.
Given that use of the de minimis exemption could significantly
limit the amount of reporting on PBT chemicals for which lower
reporting thresholds are being proposed in today's notice. EPA is
proposing to eliminate the de minimis exemption for those toxic
chemicals.
Therefore, EPA is proposing to modify 40 CFR 372.38(a) to add the
following sentence to the end thereof:
This exemption does not apply to toxic chemicals listed in
Sec. 372.28 (i.e., the chemicals for which thresholds have been
lowered), except for purposes of Sec. 372.45(d)(1).
EPA is not proposing to extend this modification to 40 CFR
372.45(d)(1) because the Agency believes that there is sufficient
information available on PBT chemicals by suppliers. Requirement of
additional information in this case would result in redundancies.
In past expansion actions, EPA has tried to retain burden reducing
options wherever feasible. However, as the TRI program evolves to meet
emerging community needs, EPA will need to reassess these exemptions
and modify them as appropriate. EPA notes that the increase in burden
resulting from eliminating the de minimis exemption for PBT chemicals
would be limited to facilities that import, process, otherwise use or
manufacture as impurities these chemicals. Many of the chemicals
identified as persistent and bioaccumulative in today's action are not
imported, processed, or otherwise used but are manufactured as
byproducts. In the preamble to the 1988 final rule implementing the
reporting provisions of EPCRA section 313 (53 FR 4500, February 16,
1988), EPA explained, that the ``de minimis limitation does not apply
to the byproducts produced coincidentally as a result of manufacturing,
processing, use, waste treatment, or disposal'' (see 53 FR 4501, column
1). EPA further explains on page 4504, column 3, its decision about the
application of the de minimis exemption to impurities and byproducts:
EPA has distinguished between toxic chemicals which are
impurities that remain with another chemical that is processed,
distributed, or used, from toxic chemicals that are byproducts
either sent to disposal or processed, distributed, or used in their
own right. EPA also considers that it would be reasonable to apply a
de minimis concentration limitation to toxic chemicals that are
impurities in another chemical or mixture. . . .Because the covered
toxic chemical as an impurity ends up in a product, most producers
of the product will frequently know whether the chemical is present
in concentrations that exceed the de minimis level, and, thus may be
listed on the Material Safety Data Sheet (MSDS) for that product
under the OSHA HCS.
This final rule does not adopt a de minimis concentration
limitation in connection with the production of a byproduct. EPA
believes that the facility should be able to quantify the annual
aggregate pounds of production of a byproduct which is not an
impurity because the substance is separated from the production
stream and used, sold, or disposed of, unlike an impurity which
remains in the product. (53 FR 4500, February 16, 1988).
Because many of the PBT chemicals being addressed in today's action
are manufactured as byproducts and the de minimis exemption does not
apply to such chemicals, eliminating it would have no effect on the
reporting of those chemicals.
For toxic chemicals in mixtures that are imported, processed, or
otherwise used, the increase in burden resulting from the elimination
of the de minimis exemption would be limited because EPCRA does not
require additional monitoring or sampling in order to comply with the
reporting requirements under EPCRA section 313. EPCRA section 313(g)(2)
states:
In order to provide the information required under this section,
the owner or operator of a facility may use readily available data
(including monitoring data) collected pursuant to other provisions
of law, or, where such data are not readily available, reasonable
estimates of the amounts involved. Nothing in this section requires
the monitoring or measurement of the quantities, concentration, or
frequency of any toxic chemical released in the environment beyond
the monitoring and measurement required under other provisions of
law or regulation.
Information used should be based on production records, monitoring, or
analytical data, guidance documents provided by EPA and trade
associations and reasonable judgement on the part of the facility's
management. No further monitoring or analysis of production, process,
or use is required.
EPA requests comment on its proposed modification of the de minimis
exemption. EPA also requests comments on whether the Agency should
modify the exemptions at 40 CFR 372.38(c) (e.g., the laboratory
exemption, and the otherwise use exemptions, including the structural
component exemption, the routine janitorial or facility grounds
maintenance exemption; the personal use exemption, the motor vehicle
maintenance exemption, and the intake air and water exemption) such
that they will not apply to PBT chemicals. The legal authority for
these exemptions is also the de minimis principle, and as noted above,
EPA is concerned that this doctrine may not be applicable to PBT
chemicals.
C. Proposed Changes to the Use of the Alternate Threshold and Form A
On November 30, 1994, EPA published a final rule (59 FR 61488) that
provides that facilities that have 500 pounds or less of production-
related waste (the sum of sections 8.1 through 8.7 of Form R) may apply
an alternate manufacture, process, and otherwise use reporting
threshold of 1 million pounds. Facilities that have less than 500
pounds of production-related waste of a listed toxic chemical and that
do not manufacture, process, or otherwise use more than 1 million
pounds of that listed toxic chemical may file a Form A certification
statement certifying that they do not exceed either of these quantities
for the toxic chemical. This certification statement includes facility
identification information and chemical identification information. EPA
adopted the alternate threshold and the Form A as a means of reducing
the burden associated with EPCRA section 313.
EPA believes that use of the existing alternate threshold and
reportable quantity for Form A would be inconsistent with the intent of
expanded PBT chemical reporting proposed in this rule. While the Form A
does provide some general information on the quantities of the chemical
that the facility manages as waste, this information is insufficient
for conducting analyses on PBT chemicals
[[Page 716]]
and would be virtually useless for communities interested in assessing
risk from releases of PBT chemicals. First, the threshold category for
amounts managed as waste does not include quantities released to the
environment as a result of remedial actions or catastrophic events not
associated with production processes (section 8.8 of Form R). Thus, the
waste threshold category will not include all releases. Given that even
small quantities of PBT chemicals may result in elevated concentrations
in the environment or in an organism, that reasonably can be
anticipated to result in significant adverse effects, EPA believes it
would be inappropriate to allow an option that would exclude
information on some releases. Second, the 500 pound waste threshold
category could be interpreted by some users, as a worst-case, to mean
that greater than 500 pounds of the chemical has been released into the
environment (i.e., 500 pounds of production-related waste as release
and some quantity of catastrophic release). Other users may assume that
the facility had no catastrophic releases and all of the toxic chemical
in waste was managed in a manner other than as release, e.g., the toxic
chemical in waste was recycled. For chemicals where any release is a
concern, an uncertainty level of 500 pounds will result in data that
are virtually unusable. As a result, EPA is proposing to exclude all
PBT chemicals from the alternate threshold of 1 million pounds.
Therefore, EPA proposes to modify 40 CFR 372.27 to add a new paragraph
(e) to read as follows:
(e) The provisions of this section do not apply to any toxic
chemicals listed in Sec. 372.28.
EPA requests comment on this limitation to the use of the Form A
certification statement.
D. Proposed Changes to the Use of Range Reporting
For releases and off-site transfers for further waste management of
less than 1,000 pounds of the toxic chemical, EPA allows facilities to
report the amount either as a whole number or by using range codes. The
reporting ranges are: 1-10 pounds; 11-499 pounds; and 500-999 pounds.
For larger releases and off-site transfers for further waste management
of the toxic chemical, the facility may report only the whole number.
While EPA provided range reporting primarily as a burden reducing
measure focused on small businesses, the Agency notes a number of
drawbacks. Use of ranges could misrepresent data accuracy because the
low or the high end range numbers may not really be that close to the
estimated value, even taking into account its inherent error (i.e.,
errors in measurements and developing estimates). The user of the data
must make a determination on whether to use the low end of the range,
the mid-point, or the upper end. For example, a release of 501 pounds
could be misinterpreted as 999 pounds if reported as a range of 500 to
999. This represents a 100 percent error. This uncertainty severely
limits the applicability of release information where the majority of
releases, particularly for PBT chemicals, are expected to be within the
amounts eligible for range reporting. Given that the large uncertainty
that would be part of these data would severely limit their utility,
EPA believes that facilities should report numerical values, not
ranges, for PBT chemicals. EPA, therefore, proposes to modify 40 CFR
372.85(b)(16)(i) to read as follows:
An estimate of the total releases in pounds per year (releases
of toxic chemicals of less than 1,000 pounds per year may be
indicated in ranges, except for toxic chemicals set forth in
Sec. 372.28) from the facility plus an indication of the basis of
estimate:
EPA also proposes to modify 40 CFR 372.85(b)(16)(ii)(B) to read as
follows:
An estimate of the amount of the chemical in waste transferred
in pounds per year (transfers of toxic chemicals of less than 1,000
pounds per year may be indicated in ranges, except for toxic
chemicals set forth in Sec. 372.28) to each off-site location, and
an indication of the basis for the estimate and an indication of the
type of treatment or disposal used.
EPA requests comment on its proposal to not allow the use of range
reporting in Form Rs for PBT chemicals.
E. Proposed Changes to the Use of the Half-Pound Rule and Whole Numbers
EPA requires that facilities report numerical quantities in
sections 5, 6, and 8 of Form R as whole numbers and does not require
more than two significant digits (except where the Agency allows range
reporting; see Unit VII.D. of this preamble). EPA currently allows
facilities to round releases of 0.5 pounds or less to zero (see Toxic
Chemical Release Inventory Reporting Forms and Instructions: Revised
1997 Version (EPA 745-K-98-001), p. 27). The combination of requiring
the reporting of whole numbers and allowing rounding to zero would
result in a significant number of facilities reporting their releases
of some PBT chemicals, notably dioxins, as zero. EPA, therefore, is
proposing that all releases or other waste management quantities
greater than a tenth of a pound of PBT chemicals (except dioxin) be
reported, provided that the appropriate activity threshold has been
exceeded. Releases and other waste management activities would continue
to be reported to two significant digits. For quantities of 10 pounds
or greater only whole numbers would be required to be reported. For
quantities less than 10 pounds, fractional quantities, e.g., 6.2
pounds, rather than whole numbers would be required, provided the
accuracy in the underlying data on which the estimate is based supports
this level of precision. For the category of dioxin and dioxin-like
compounds, which have a proposed reporting threshold of 0.1 gram, EPA
is proposing that facilities report all releases and other waste
management activities greater than 100 micrograms (i.e., 0.0001 gram).
Remember, EPCRA only requires reporting to be based on the best readily
available information or reasonable estimates.
EPA requests comment on the proposed requirement that, other than
for the dioxin and dioxin-like compounds category, all non-zero
releases of PBT chemicals greater than one tenth of a pound be
reported. EPA also requests comment on using fractional quantities for
reports under 10 pounds. EPA also requests comment on the proposed
requirement that all non-zero releases of dioxin and dioxin-like
compounds greater than 100 micrograms be reported.
VIII. Proposed Changes to Other EPCRA Reporting Requirements
A. Individual Reporting of Tetraethyl and Tetramethyl Lead
The alkyl lead compounds tetraethyl lead (CAS No. 78-00-2) and
tetramethyl lead (CAS No. 75-74-1) are currently reportable under the
EPCRA section 313 category listing for lead compounds. These alkyl lead
compounds appear on the Binational Level 1 list of chemicals that have
been identified for virtual elimination from the Great Lakes and are
thus of special concern. It is not currently possible to individually
track these two alkyl lead compounds under section 313 since they are
not specifically identified in reports submitted under the lead
compounds category. In order to track these alkyl lead compounds, EPA
is proposing that separate reports be filed for these two members of
the lead compounds category, which will allow identification of
facilities that have these specific lead compounds. EPA believes that
this method of reporting is consistent with the purpose and legislative
history of EPCRA section
[[Page 717]]
313, as illustrated in the following passage from the Conference
report:
In cases where the list of chemicals for which reporting is
required refers to compounds of a ``chemical'' which is a group of
related chemicals rather than a specific chemical with accompanying
Chemical Abstracts Service (CAS) number, the person submitting the
form may include aggregate data including all releases of those
individual chemicals on one reporting form rather than listing data
separately for each individual chemical in the group. Thus, for
example, a single form can be submitted for ``polybrominated
biphenyls'' as listed in Senate Environment and Public Works
Committee Print No. 99-169 without identifying the individual
polybrominated biphenyls being released or reporting release data
separately for each one. This does not preclude the Administrator
from requiring reporting on individual chemicals for which aggregate
reporting otherwise would be required. (H. Rep. 99-962, 99th Cong.,
2nd Sess., p. 296 (Oct. 3, 1986)).
As the last sentence in this passage clearly indicates, EPA is not
precluded from requiring that members of a chemical category be
reported separately.
Under this proposal, if any of the current manufacture, process, or
otherwise use reporting thresholds for the lead compounds category are
met, a facility would file one report for all members of the category
excluding the two alkyl lead compounds. If the facility has 1 pound or
more of tetraethyl or tetramethyl lead applicable toward the threshold
determinations for the lead compounds category then separate reports
would be filed for tetraethyl and tetramethyl lead. As an alternative
proposal, the amounts of tetraethyl and tetramethyl lead could be
combined and included in a single separate report.
EPA requests comment on whether this provision is appropriate, and
if so, whether two separate reports should be filed for each of these
alkyl lead compounds or whether one report that includes the amounts of
both tetraethyl and tetramethyl lead should be required.
For this initial rulemaking on PBT chemicals, EPA reviewed the
persistence and bioaccumulation data for tetraethyl lead and
tetramethyl lead but not the available data for elemental lead or other
lead compounds. EPA is aware of additional available data that may
indicate that lead and/or lead compounds meet the bioaccumulation
criteria discussed in this proposed rule. EPA intends to review these
additional data to determine if lead and/or lead compounds should be
considered PBT chemicals and whether it would be appropriate to
establish lower reporting thresholds for these chemicals. Any such
determination will be made part of an additional rulemaking activity.
B. Reporting Limitation for Cobalt and Vanadium in Alloys
EPA is proposing to list ``vanadium'' and ``vanadium compounds''
and delete the EPCRA section 313 listing for ``vanadium (fume or
dust).'' EPA is also requesting comment on the adequacy of existing
studies for determining the bioaccumulation potential of cobalt and
cobalt compounds. Depending on the comments received, EPA may lower the
reporting thresholds for cobalt and cobalt compounds. Both of these
metals can be found in various types of alloys and are subject to
reporting under section 313 when contained in these alloys. In response
to several petitions that EPA has received, the Agency has been
reviewing the issue of how metals contained in alloys should be
reported under section 313. Because this issue is currently being
reviewed, EPA does not believe that, at this time, it would be
appropriate to increase reporting for those facilities that must submit
reports for these metals when contained in alloys. EPA is therefore
proposing to limit the reporting for vanadium and cobalt to exclude
alloys that contain these metals from the lower reporting thresholds.
Since vanadium without the fume or dust qualifier would be a new
section 313 listing EPA does not believe that, at this time, facilities
should be subject to any additional reporting on alloys containing
vanadium. EPA is therefore proposing to include the qualifier ``except
when contained in an alloy'' in the new listing for vanadium. Including
this qualifier will effectively exclude vanadium from reporting when
contained in an alloy. EPA requests comment on the proposed qualifier
to the vanadium listing.
If EPA lowers reporting thresholds for cobalt and cobalt compounds
the situation would be somewhat more complicated since, unlike the
proposed revised listing for vanadium, it is already a listed section
313 chemical and thus facilities must currently report on cobalt when
contained in alloys. Since EPA has not made any final decisions
concerning the reporting of cobalt or other metals in alloys EPA would
not be prepared to make any changes, including lowering thresholds, to
the current reporting requirements for cobalt when contained in alloys.
If the reporting threshold for cobalt and cobalt compounds is lowered
after considering comments, EPA would propose to exclude cobalt
contained in alloys from the lower reporting thresholds and retain the
current reporting thresholds for cobalt when contained in alloys. This
would result in no changes to the reporting requirements for cobalt
contained in alloys until EPA makes a final determination on whether
there should be any changes to the reporting requirements for metals
contained in alloys. However, EPA would not simply add the same
qualifier to the listing for cobalt that is proposed to be added to
vanadium since the alloy forms of cobalt will still be reportable but
only under the current reporting thresholds. Therefore, EPA would make
this distinction at 40 CFR 372.28, which is the new section of the CFR
that will set forth the lower section 313 reporting thresholds being
proposed in this action. This section would indicate that only cobalt
not contained in an alloy would be subject to the lower reporting
thresholds. As with the lower reporting thresholds proposed for other
chemicals, EPA would also make this distinction clear in the section
313 Form R and Form A reporting instructions and other documents.
For purposes of section 313 reporting, EPA considers metal
compounds that are used to make alloys to exist as the parent metal in
the alloys. Under this proposed limitation for alloys, reporting
facilities that use vanadium or cobalt to make alloys would still
report for these metals since they are being used to manufacture an
alloy. However, once incorporated into the alloy vanadium would not be
reportable. Similarly, if EPA lowers the reporting threshold for cobalt
and cobalt compounds in the final rule, cobalt incorporated in an alloy
would not be subject to the lower reporting thresholds. Thus, the
limitation on alloys reporting for vanadium and cobalt would apply to
vanadium and cobalt compounds once they are incorporated into an alloy.
The cutting, grinding, shaving, etc. of an alloy does not negate the
reporting limitations for alloys containing vanadium and cobalt.
IX. Request for Comment
EPA recognizes that as the TRI Program has expanded, total
reporting burden on the regulated community has increased. EPA is
genuinely interested in reducing TRI reporting burden, while assuring
that the goals and objectives of EPCRA section 313 continue to be met.
During the inter-agency review process, EPA received several
suggestions that, if implemented, may alter TRI reporting burden. In
many cases, burden might decrease; in others it might increase. EPA
welcomes comments on the following suggestions, particularly with
respect to the resulting impacts on total burden and the Agency's
ability to
[[Page 718]]
continue to meet the goals and objectives of EPCRA section 313.
During the inter-agency review process the issue of using other
factors in identifying PBT chemicals and/or in setting alternative
reporting thresholds was raised. For example, it was suggested that EPA
use throughput data and emissions factors to estimate the releases that
would be reported at an ``average'' facility at each of the identified
options for a lowered threshold and that EPA then use those estimates
to select the lowered threshold that would capture some overall
percentage of releases, e.g., 75-80%. EPA has not estimated the total
national releases to all media for the toxic chemicals in this proposed
rule (and in previously proposed and final rules) because EPA believes
that (1) there is insufficient information currently available for
these chemicals and (2) there is insufficient information on the
numerous processes employed by all the sectors involved to calculate a
comprehensive release estimate for the sector. While there are data
available for some chemicals for some sectors, comprehensive data for
all sectors and chemicals are unavailable and consequently, decisions
would need to be based on an incomplete data set. It was also suggested
that EPA might consider ``throughput'' (i.e., manufacture, processing,
and use) in setting reporting thresholds. While data are generally more
available on throughput than on releases, EPA also did not attempt to
estimate the proportion of throughput covered by alternative reporting
thresholds because of its concern that these estimates may not be of
sufficient quality and completeness to help inform the selection of
appropriate reporting thresholds with sufficient scientific certainty.
EPA invites comment on these approaches and requests comment as well on
appropriate methodologies for estimating releases and/or throughput,
and on estimating releases from throughput data. EPA welcomes
suggestions as well on other approaches that may assist the Agency when
it is developing options for lowering TRI reporting thresholds, adding
new facilities or adding additional chemicals.
In this proposal, EPA is using two criteria--the persistence and
bioaccumulative characteristics--to identify those TRI-listed chemicals
that would be subject to the lower PBT reporting thresholds. These
criteria were also primary factors in developing the proposed
thresholds. EPA believes it has discretion to use other factors as part
of its basis for setting lower reporting thresholds. During the inter-
agency review process the issue of using alternative criteria in
identifying PBT chemicals and/or in setting alternative reporting
thresholds was raised. These include, among others, degree of toxicity,
environmental presence, and biomagnification. For example, it has been
suggested that EPA should consider a chemical's potential to biomagnify
(i.e., to increase in the tissues of organisms as it moves up the food
chain) in determining if reporting thresholds should be lowered for PBT
chemicals. EPA requests comment on whether these other factors should
be considered in establishing reporting thresholds for PBT chemicals,
and on what data might be available to use in considering such factors.
For this issue, EPA specifically requests comment on the state of the
science related to biomagnification and the current capability to
establish appropriate quantitative criteria for biomagnification.
It has also been suggested that EPA should consider lowering the
reporting thresholds for toxic chemicals that are either persistent or
bioaccumulative. It has been suggested that if a toxic chemical meets
either criteria, the toxic chemical is of concern if it can result in
elevated concentrations in either the environment or in organisms. For
example, metals are persistent and releases of metals will result in
elevated concentrations in the environment because they do not degrade.
This is independent of whether or not the metal is also
bioaccumulative. EPA requests comment on whether it should consider
lowering the reporting thresholds for EPCRA section 313 chemicals that
are either persistent or bioaccumulative based on the criteria proposed
in this rule.
During the inter-agency review process it was also suggested that
EPA propose other mechanisms for further minimizing the potential
impacts associated with lowering the reporting thresholds for PBT
chemicals. For example, it was suggested that EPA develop a modified
Form A with thresholds more appropriate for the PBT chemicals.
Specifically, it was suggested that EPA develop an alternate threshold
and a reportable quantity lower than the current Form A for the PBT
chemicals. This could also be done in conjunction with other changes to
the Form A that EPA is considering. While not adverse to considering
such an approach, EPA believes that, in order to consider such an
alternate threshold and reportable quantity for PBT chemicals, it may
be appropriate for the Agency to collect and analyze several years
worth of data at the lowered thresholds, including data from the
recently added industry sectors, before it considers developing an
alternate Form A threshold and reportable quantity appropriate for PBT
chemicals. EPA requests comment on whether it should consider an
alternate threshold and reportable quantity for PBT chemicals, as well
as any suggestion on what should be considered if the Agency were to
move forward with such a proposal.
There may also be other ways to minimize the burden associated
with lowering the threshold. For example, one alternative to
eliminating the de minimis exemption altogether would be to establish
lower de minimis thresholds for PBT chemicals. EPA believes that such a
modified exemption would need to be structured to ensure reporting on
the majority of releases for the PBTs covered by this rule, while still
providing burden relief for those facilities which import, process, use
or manufacture extremely small concentrations (as impurities) of these
chemicals. It has also been suggested by others that EPA might consider
an activity qualifier restricting the lower reporting threshold to the
manufacture of the PBTs, retaining the higher current thresholds with
respect to import, process, or use activities. This would extend the
approach EPA is proposing for dioxin to other PBT chemicals. EPA
requests comment on these options and other similar approaches that
might be adopted to reduce the burden associated with this PBT
proposal.
It has also been suggested that EPA modulate the thresholds for
reporting, requiring reporting at the lower thresholds every other year
and reporting at the current thresholds in the out years. Because this
would have the effect of modifying the reporting frequency for many
facilities, EPA believes that it must comply with the EPCRA section
313(i) requirements for modifying the EPCRA section 313 reporting
frequency. EPA is requesting comment on the utility of a modulated
approach and whether that approach would provide for significant burden
reduction for affected facilities. Specifically, EPA is interested in
the comments on the approach itself as well as comments on whether EPA
should modify the reporting frequency pursuant to EPCRA section 313(i)
for either a select group of chemicals, such as the PBTs, or for a
subset of facilities. In providing comments on this issue, commenters
are encouraged to focus on the procedures laid out in section 313(i) of
EPCRA. They are as follows:
[[Page 719]]
To modify the reporting frequency, EPA must first notify
Congress and then delay initiating the rulemaking for at least 12
months. In addition, EPA must find:
(A) ...that the modification is consistent with the provisions
of subsection (h) of [section 313] based on -
(i) experience from previously submitted toxic chemical release
forms,
(ii) determinations made under paragraph (3).]
Paragraph (3), in turn, provides that EPA must determine
(A) The extent to which information relating to the proposed
modification provided on the toxic chemical release forms has been
used by the Administrator or other agencies of the Federal
government, States, local governments, health professionals and the
public.
(B) The extent to which information is (i) readily available to
potential users from other sources, such as State reporting
programs, and (ii) provided to the Administrator under another
Federal law or through as State program.
(C) The extent to which the modification would impose additional
and unreasonable burdens on facilities subject to the reporting
requirements under this section.
EPA welcomes comment on the availability of information that would
allow the Agency to make the requisite findings under paragraph 3(B),
especially how consideration of alternate reporting requirements should
pertain to the recently added SIC codes for which reporting has not yet
been received, the lack of readily available information on PBT
chemicals from existing sources, and what available information may
exist to allow EPA to address the requirements of the law. Therefore,
EPA would be particularly interested in information relating to the
findings required under paragraph 3(B).
X. Economic Analysis
EPA has prepared an economic analysis of the impact of this
proposed action, which is contained in a document entitled ``Economic
Analysis of the Proposed Rule to Modify Reporting of Persistent
Bioaccumulative Toxic Chemicals under EPCRA Section 313'' (Ref. 79).
This document is available in the public docket for this rulemaking.
The analysis assesses the costs, benefits, and associated impacts of
the proposed rule, including potential effects on small entities. The
major findings of the analysis are briefly summarized here.
The estimates included in the following discussion reflect the
estimated impacts associated with the PBT chemicals identified in the
proposed regulatory text. However, as indicated previously, the Agency
is also considering and seeking comment on lowering the reporting
thresholds for cobalt and cobalt compounds. The estimated effect of
lowering the reporting thresholds for cobalt and cobalt compounds would
result in an estimated 3,500 reports, at an estimated burden of 370,000
hours (at a cost of $25 million) in the first year and an estimated
burden of 208,000 hours (at a cost of $14 million) in each subsequent
year. EPA estimates that 2 small businesses may experience impacts
between 1% and 3% in subsequent years. Additional information about the
potential effects associated with lowering the reporting thresholds for
cobalt and cobalt compounds is included in the economic analysis (see
Ref. 79).
A. Need for the Rule
Federal regulations exist, in part, to address significant market
failures. Markets fail to achieve socially efficient outcomes when
differences exist between market values and social values. Two causes
of market failure are externalities and information asymmetries. In the
case of negative externalities, the actions of one economic entity
impose costs on parties that are external'' to any market transaction.
For example, a facility may release toxic chemicals without accounting
for the consequences to other parties, such as the surrounding
community, and the prices of that facility's goods or services thus
will fail to reflect those costs. The market may also fail to
efficiently allocate resources in cases where consumers lack
information. For example, where information is insufficient regarding
toxic releases, individuals' choices regarding where to live and work
may not be the same as if they had more complete information. Since
firms ordinarily have little or no incentive to provide information on
their releases and other waste management activities involving toxic
chemicals, the market fails to allocate society's resources in the most
efficient manner.
This proposed rule is intended to address the market failures
arising from private choices about PBT chemicals that have societal
costs, and the market failures created by the limited information
available to the public about the release and other waste management
activities involving PBT chemicals. Through the collection and
distribution of facility-specific data on toxic chemicals, TRI
overcomes firms' lack of incentive to provide certain information, and
thereby serves to inform the public of releases and other waste
management of PBT chemicals. This information enables individuals to
make choices that enhance their overall well-being. Choices made by a
more informed public, including consumers, corporate lenders, and
communities, may lead firms to internalize into their business
decisions at least some of the costs to society relating to their
releases and other waste management activities involving PBT chemicals.
In addition, by helping to identify areas of concern, set priorities
and monitor trends, TRI data can also be used to make more informed
decisions regarding the design of more efficient regulations and
voluntary programs, which also moves society towards an optimal
allocation of resources.
If EPA were not to take this proposed action adding certain PBT
chemicals to TRI and lowering reporting thresholds, the market failure
(and the associated social costs) resulting from the limited
information on the release and disposition of PBT chemicals would
continue. EPA believes that today's action will improve the scope of
multi-media data on the release and disposition of PBT chemicals. This,
in turn, will provide information to the public, empower communities to
play a meaningful role in environmental decision-making, and improve
the quality of environmental decision-making by government officials.
In addition, this action will serve to generate information that
reporting facilities themselves may find useful in such areas as
highlighting opportunities to reduce chemical use or release and
thereby lower costs of production and/or waste management. EPA believes
that these are sound rationales for adding PBT chemicals to the TRI
program and lowering reporting thresholds.
B. Regulatory Options
EPA evaluated a number of options in the development of this
proposed rule. The options were created by varying the reporting
thresholds for the PBT chemicals from their current levels of 25,000
pounds for manufacture and processing, and 10,000 pounds for otherwise
use of EPCRA Section 313 chemicals. The options in table 3 summarize
the scope of EPA's analysis.
[[Page 720]]
Table 3.--Summary of Options Considered
------------------------------------------------------------------------
Regulatory Option Description of Option
------------------------------------------------------------------------
Option 1 Reporting threshold of 1 pound
manufactured, processed, or
otherwise used for the highly
persistent bioaccumulative
chemicals. Reporting threshold of
10 pounds manufactured, processed,
or otherwise used for the
persistent bioaccumulative
chemicals. Reporting threshold of
0.1 gram manufactured for the
dioxin and dioxin-like compounds
category.
------------------------------------------------------------------------
Option 2 Reporting threshold of 10 pounds
manufactured, processed, or
otherwise used for the highly
persistent bioaccumulative
chemicals. Reporting threshold of
100 pounds manufactured,
processed, or otherwise used for
the persistent bioaccumulative
chemicals. Reporting threshold of
0.1 gram manufactured for the
dioxin and dioxin-like compounds
category. This is the preferred
option presented in the regulatory
text.
------------------------------------------------------------------------
Option 3 Reporting threshold of 100 pounds
manufactured, processed, or
otherwise used for the highly
persistent bioaccumulative
chemicals. Reporting threshold of
1,000 pounds manufactured,
processed, or otherwise used for
the persistent bioaccumulative
chemicals. Reporting threshold of
0.1 gram manufactured for the
dioxin and dioxin-like compounds
category.
------------------------------------------------------------------------
Option 4 Reporting threshold of 1,000 pounds
manufactured, processed, or
otherwise used for the highly
persistent bioaccumulative
chemicals and the persistent
bioaccumulative chemicals.
Reporting threshold of 1.0 gram
manufactured for the dioxin and
dioxin-like compounds category.
------------------------------------------------------------------------
Reporting under all four options is affected by other proposed
changes in reporting requirements for PBT chemicals. These proposed
changes include the elimination of the de minimis exemption for PBT
chemicals with lower thresholds and a requirement for all facilities to
report on PBT chemicals using the Form R. The effect of the other
proposed changes on reporting is described in chapter 2 of the economic
analysis (Ref. 79).
Table 4 in section E.4. of this unit displays, for each option, the
estimated number of additional reports for PBT chemicals expected under
EPCRA section 313.
In proposing this rule, EPA has sought to balance the public's
right to know about toxic chemical releases and other waste management
practices in their neighborhoods and the benefits provided by this
expanded knowledge with the costs the rule will likely impose on
industry, including the impact on small entities.
C. Costs
The proposed rule will result in the expenditure of resources that,
in the absence of the regulation, could be used for other purposes. The
cost of the proposed rule is the value of these resources in their best
alternative use. Most of the costs of the proposed rule result from
requirements on industry. Table 5 in section E.4. of this unit displays
the industry costs for each option based on the estimated number of
facilities affected and the estimated number of additional reports.
Under the option presented in the regulatory text (Option 2),
approximately 9,500 facilities will submit approximately 17,000
additional Form R reports annually. As shown, aggregate industry costs
in the first year for the proposed alternative are estimated to be $126
million; in subsequent years they are estimated to be $70 million per
year. Industry costs are lower after the first year because facilities
will be familiar with the reporting requirements, and many will be able
to update or modify information from the previous year's report. EPA is
expected to expend $1.8 million in the first year, and $1.4 million in
subsequent years as a result of the proposed rule.
D. Benefits
In enacting EPCRA and PPA, Congress recognized the significant
benefits of providing the public with information on toxic chemical
releases and other waste management practices. TRI has empowered the
Federal government, State governments, industry, environmental groups
and the general public to fully participate in an informed dialogue
about the environmental impacts of toxic chemicals in the United
States. TRI's publicly available data base provides quantitative
information on toxic chemical releases and other waste management
practices. Since TRI's inception in 1987, the public, government, and
the regulated community have had the ability to understand the
magnitude of chemical releases in the United States, and to assess the
need to reduce the uses and releases of toxic chemicals. TRI enables
all interested parties to establish credible baselines, to set
realistic goals for environmental progress over time, and to measure
progress in meeting these goals over time. The TRI system is a neutral
yardstick by which progress can be measured by all stakeholders.
The information reported to TRI increases knowledge of the amount
of toxic chemicals released to the environment and the potential
pathways of exposure, improving scientific understanding of the health
and environmental risks of toxic chemicals; allows the public to make
informed decisions on where to work and live; enhances the ability of
corporate leaders and purchasers to more accurately gauge a facility's
potential environmental liabilities; provides reporting facilities with
information that can be used to save money as well as reduce emissions;
and assists Federal, State, and local authorities in making better
decisions on acceptable levels of toxic chemicals in the environment.
There are two types of benefits associated with TRI reporting those
resulting from the actions required by the rule (such as reporting and
recordkeeping), and those derived from follow-on activities that are
not required by the rule. Benefits of activities required by the rule
include the value of improved knowledge about the release and waste
management of toxic chemicals, which leads to improvements in
understanding, awareness and decisionmaking. It is expected that this
rulemaking will generate such benefits by providing readily accessible
information that otherwise would not be available to the public. The
proposed rule will benefit ongoing research efforts to understand the
risks posed by PBT chemicals and to evaluate policy strategies that
address the risks.
The second type of benefits derive from changes in behavior that
may
[[Page 721]]
result from the information reported to EPCRA section 313. These
changes in behavior, including reductions in releases of and changes in
the waste management practices for toxic chemicals may yield health and
environmental benefits. These changes in behavior come at some cost,
and the net benefits of the follow-on activities are the difference
between the benefits of decreased chemical releases and transfers and
the costs of the actions needed to achieve the decreases.
Because the state of knowledge about the economics of information
is not highly developed, EPA has not attempted to quantify the benefits
of adding chemicals to TRI or changing reporting thresholds.
Furthermore, because of the inherent uncertainty in the subsequent
chain of events, EPA has also not attempted to predict the changes in
behavior that result from the information, or the resultant net
benefits, (i.e., the difference between benefits and costs). EPA does
not believe that there are adequate methodologies to make reasonable
monetary estimates of either the benefits of the activities required by
the proposed rule, or the follow-on activities. The economic analysis
of the proposed rule, however, does provide illustrative examples of
how the proposed rule will improve the availability of information on
PBT chemicals (Ref. 79).
E. Impacts on Small Entities
In accordance with the Regulatory Flexibility Act (RFA) and the
Agency's longstanding policy of always considering whether there may be
a potential for adverse impacts on small entities, the Agency has also
evaluated the potential impacts of this proposed rule on small
entities. The Agency's analysis of potentially adverse economic impacts
is included in the Economic Analysis for this proposed rule (Ref. 79).
The following is a brief overview of EPA's findings.
1. Overall methodology. This proposed rule may affect both small
businesses and small governments. For the purpose of its analysis for
the proposed rule, EPA defined a small business using the small
business size standards established by the Small Business
Administration (SBA). (For example, the SBA size standard is 500
employees for approximately 75% of the manufacturing industries, and
either 750, 1,000 or 1,500 for the remaining manufacturing industries,
which would mean that more than 98.5 percent of the manufacturing firms
are classified as small businesses (Ref. 80)). EPA is interested in
receiving comments on its use of the SBA size standards for defining
small businesses. EPA defined small governments using the RFA
definition of jurisdictions with a population of less than 50,000. No
small organizations are expected to be affected by the proposed rule.
Only those small entities that are expected to submit at least one
report are considered to be affected for the purpose of the small
entity analysis, although EPA recognizes that other small entities will
conduct compliance determinations under lower thresholds. The number of
affected entities will be smaller than the number of affected
facilities, because many entities operate more than one facility.
Impacts were calculated for both the first year of reporting and
subsequent years. First year costs are typically higher than continuing
costs because firms must familiarize themselves with the requirements.
Once firms have become familiar with how the reporting requirements
apply to their operations, costs fall. EPA believes that subsequent
year impacts present the best measure to judge the impact on small
entities because these continuing costs are more representative of the
costs firms face to comply with the proposed rule.
EPA analyzed the potential cost impact of the proposed rule on
small businesses and governments for the manufacturing sector and in
each of the recently added industry sectors separately in order to
obtain the most accurate assessment for each. EPA then aggregated the
analyses for the purpose of determining whether it could certify that
the proposed rule will not, if promulgated, have a significant economic
impact on a substantial number of small entities.'' RFA section 605(b)
provides an exemption from the requirement to prepare a regulatory
flexibility analysis for a rule where an agency makes and supports the
certification statement quoted above. EPA believes that the statutory
test for certifying a rule and the statutory consequences of not
certifying a rule all indicate that certification determinations may be
based on an aggregated analysis of the rule's impact on all of the
small entities subject to it.
2. Small businesses. EPA used annual compliance costs as a
percentage of annual company sales to assess the potential impacts on
small businesses of this rule. EPA believes that this is a good measure
of a firm's ability to afford the costs attributable to a regulatory
requirement, because comparing compliance costs to revenues provides a
reasonable indication of the magnitude of the regulatory burden
relative to a commonly available measure of a company's business
volume. Where regulatory costs represent a small fraction of a typical
firm's revenue (for example, less than 1%, but not greater than 3%),
EPA believes that the financial impacts of the regulation may be
considered not significant. As discussed above, EPA also believes that
it is appropriate to apply this measure to subsequent year impacts.
Based on its estimates of additional reporting as a result of the
proposed rule, the Agency estimates that approximately 5,300 businesses
will be affected by the proposed rule, and that approximately 3,600 of
these businesses are classified as small based on the applicable SBA
size standards. For the first reporting year, EPA estimates that
approximately 16 small businesses may bear compliance costs between 1%
and 3% of revenues, and that no small businesses will bear costs
greater than 3%. In subsequent years, EPA estimates that approximately
4 small businesses may bear compliance costs between 1% and 3% of
revenues, and that no small businesses will bear costs greater than 3%.
As stated above, EPA believes that subsequent-year impacts are the
appropriate measure of small business impacts.
3. Small governments. To assess the potential impacts on small
governments, EPA used annual compliance costs as a percentage of annual
government revenues to measure potential impacts. Similar to the
methodology for small businesses, this measure was used because EPA
believes it provides a reasonable indication of the magnitude of the
regulatory burden relative to a government's ability to pay for the
costs, and is based on readily available data.
EPA estimates that 46 publicly owned electric utility facilities,
operated by a total of 37 municipalities, may be affected. Of these, an
estimated 17 are operated by small governments (i.e., those with
populations under 50,000). It is estimated that none of these small
governments will bear annual costs greater than 1% of annual government
revenues.
4. All small entities. As discussed above, approximately 4 small
businesses are expected to bear costs over 1% of revenues after the
first year of reporting. None of the affected small governments are
estimated to bear costs greater than 1% of revenues. No small
organizations are expected to be affected by the proposed rule. Thus,
the total number of small entities with impacts above 1% of revenues
does not change when the results are aggregated for all small entities
(i.e., small businesses, small governments, and small organizations).
[[Page 722]]
Table 4.--Summary of Reporting Under Regulatory Options
----------------------------------------------------------------------------------------------------------------
Estimated Number of Reports (Annual)
Chemical or Chemical Category -------------------------------------------------------------------------------
Option 1 Option 2 Option 3 Option 4
----------------------------------------------------------------------------------------------------------------
Alkyl lead (tetraethyl lead and 134 134 134 134
tetramethyl lead)
----------------------------------------------------------------------------------------------------------------
Benzo(g,h,i)perylene 798 353 6 0
----------------------------------------------------------------------------------------------------------------
Dioxin and dioxin-like compounds 1,863 1,863 1,863 812
category
----------------------------------------------------------------------------------------------------------------
Hexachlorobenzene 3,772 778 73 3
----------------------------------------------------------------------------------------------------------------
Mercury; mercury compounds 11,378 5,230 2,367 1,454
category
----------------------------------------------------------------------------------------------------------------
Octachlorostyrene 303 230 67 65
----------------------------------------------------------------------------------------------------------------
Pentachlorobenzene 3,314 707 36 11
----------------------------------------------------------------------------------------------------------------
Pesticides (Aldrin, Chlordane, 280 264 199 186
Dicofol, Heptachlor, Isodrin,
Methoxychlor, Pendimethalin,
Toxaphene, Trifluralin)
----------------------------------------------------------------------------------------------------------------
Polycyclic aromatic compounds 5,488 4,699 4,046 2,620
(PAC) category
----------------------------------------------------------------------------------------------------------------
Polychlorinated biphenyls (PCBs) 3,605 2,267 1,259 177
----------------------------------------------------------------------------------------------------------------
Tetrabromobisphenol A 150 150 150 150
----------------------------------------------------------------------------------------------------------------
Vanadium; vanadium compounds 654 654 654 654
category
----------------------------------------------------------------------------------------------------------------
Total 31,739 17,329 10,854 6,266
----------------------------------------------------------------------------------------------------------------
Table 5.--Summary of Reporting and Industry Cost of Regulatory Options
----------------------------------------------------------------------------------------------------------------
Annual Estimated Industry Costs ($ million
---------------------------------------- per year)
Regulatory Options Number of ---------------------------------------
Reporting Number of Reports
Facilities First Year Subsequent Years
----------------------------------------------------------------------------------------------------------------
1. Reporting threshold of 1 lb 18,082 31,739 $232 $127
for highly PB chemicals, 10 lb
for PB chemicals, 0.1 gram for
dioxin
----------------------------------------------------------------------------------------------------------------
2. Reporting threshold of 10 lb 9,515 17,329 $126 $70
for highly PB chemicals, 100 lb
for PB chemicals, 0.1 gram for
dioxin
----------------------------------------------------------------------------------------------------------------
3. Reporting threshold of 100 lb 6,187 10,854 $78 $44
for highly PB chemicals, 1,000
lb for PB chemicals, 0.1 gram
for dioxin
----------------------------------------------------------------------------------------------------------------
4. Reporting threshold of 1,000 3,748 6,266 $45 $25
lb for highly PB chemicals and
PB chemicals, 1 gram for dioxin
----------------------------------------------------------------------------------------------------------------
XI. References
1. The Great Lakes Binational Toxics Strategy, Canada -- United
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Substances in the Great Lakes, signed by Carol Browner, Administrator
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2. USEPA, OPPT. Support Document for the Addition of Certain
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to-Know Act. U.S. Environmental Protection Agency, Washington DC
(1998).
3. USEPA, OSWER. Waste Minimization Prioritization Tool Beta Test
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4. Atkinson, R., ``Kinetics and Mechanisms of the Gas-Phase
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5. Webster, E., Mackay, D. and F Wania, F, ``Evaluating
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[[Page 723]]
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7. Altshuller, A.P., ``Ambient Hydroxyl Radical Concentration:
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17. ICF Incorporated. Focus Chemicals for the Clean Air Act
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Paper presented at the SETAC Foundation workshop ``Environmental Risk
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Nottawasaga Inn, Alliston, ON, Canada.
19. Environment Canada. Towards a Toxic Substances Management
Policy for Canada: A Discussion Document. September 1994.
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Screening Criteria: Report to the U.S. EPA International Toxics
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21. NAFTA-CEC. Process for Identifying Candidate Substances for
Regional Action under the Sound Management of Chemicals Initiative.
Report to the North American working group on the sound management of
chemicals by the task force on criteria. Draft, July 1997.
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Persistent Organic Pollutants. United Nations Economic Commission for
Europe. EB.AIR/WG.5/R.72, March 10, 1997.
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Management for PTBs. Chemical Manufacturers Association. February 1996.
24. ICCA. Position on Persistent Organic Pollutants (POPs). In
letter to M. Mercier from International Council of Chemical
Associations, dated February 23, 1996.
25. USEPA. Fish BCF, OPPTS 850.1730. Ecological Effects Test
Guidelines (draft), United States Environmental Protection Agency,
Washington, DC, EPA report no. 712-C-96-129. April 1996.
26. USEPA. Oyster BCF, OPPTS 850.1710. Ecological Effects Test
Guidelines (draft), United States Environmental Protection Agency,
Washington, DC, EPA report no. 712-C-96-127. April 1996.
27. USEPA. Daphnid Chronic Toxicity Test, OPPTS 850.1300.
Ecological Effects Test Guidelines (draft), United States Environmental
Protection Agency, Washington, DC, EPA report no. 712-C-96-120. April
1996.
28. USEPA. Mysid Chronic Toxicity Test, OPPTS 850.1350. Ecological
Effects Test Guidelines (draft), United States Environmental Protection
Agency, Washington, DC, EPA report no. 712-C-96-166. April 1996.
29. USEPA. Fish Early-Life Stage Toxicity Test, OPPTS 850.1400.
Ecological Effects Test Guidelines (draft), United States Environmental
Protection Agency, Washington, DC, EPA report no. 712-C-96-121. April
1996.
30. USEPA. Tadpole Sediment Subchronic Toxicity Test, OPPTS
850.1800. Ecological Effects Test Guidelines (draft), United States
Environmental Protection Agency, Washington, DC, EPA report no. 712-C-
96-132. April 1996.
31. CITI. Biodegradation and Bioaccumulation: Data of Existing
Chemicals Based on the CSCL Japan. Edited by Chemicals Inspection
Testing Institute, Japan Chemical Industry Ecology-Toxicology
Information Center, Tokyo, Japan. October 1992. ISBN 4-89074-101-1.
32. USEPA. AQUIRE, the Aquatic Toxicity Information Retrieval
Database. September 22, 1995. http://www.epa.gov/medatwrk/databases/
aquire.html
33. USEPA, OPPT. Persistent, Bioaccumulative Substances on the
Toxics Release Inventory (TRI): Persistence Screening Criteria for Air,
Soil, Sediment. Boethling, R.S., U.S. Environmental Protection Agency.
(January 21, 1998).
34. Wania, F. and Mackay, D., ``Tracking the Distribution of
Persistent Organic Pollutants.'' Environ. Sci. Technol. v. 30, (1996)
pp. 390A-396A.
35. Mackay, D., DiGuardo, A., Paterson, S., and Cowan, C.E.,
``Evaluating the Environmental Fate of a Variety of Types of Chemicals
Using the EQC Model.'' Environ. Toxicol. Chem. v. 15, (1996), pp. 1627-
1637.
36. Mackay, D., ``Finding Fugacity Feasible.'' Environ. Sci.
Technol. v. 13, (1979), pp. 1218-1223.
37. Mackay, D., Multimedia Environmental Models: The Fugacity
Approach. Lewis: Chelsea, MI. (1991).
38. Mackay, D., Paterson, S., and Shiu, W.Y., ``Generic Models for
Evaluating the Regional Fate of Chemicals.'' Chemosphere v. 24, (1992),
pp. 695-717.
39. Rand, G.M., Fundamentals of Aquatic Toxicology, 2nd. Ed. Taylor
Francis, Washington, DC, (1995), 1125 pp.
40. Meylan, W.M., Howard, P.H., and Boethling, R.S., ``Improved
Method for Estimating Bioconcentration Factor from Octanol/Water
Partition Coefficient.'' Environ. Toxicol. Chem., in press.
41. USEPA, OPPT. Memorandum from Jerry Smrchek, Ph.D., Biologist,
Existing Chemicals Assessment Branch, Risk Assessment Division to Myra
L. Karstadt, Toxic Release Inventory Branch, Environmental Assistance
Division. August 25, 1997. Subject: PBT Project: Identification,
Support and
[[Page 724]]
Justification of Bioaccumulation Criteria.
42. Veith, G.D., Kosian, P., ``Estimating Bioconcentration
Potential from Octanol/Water Partition Coefficients.'' In Physical
Behaviour of PCBs in the Great Lakes. Mackay, D., et al, eds Ann Arbor
Science, Ann Arbor, MI, (1983), pp 269-282.
43. Barron, M.G., ``Bioconcentration.'' Environmental Science
Technology v. 24, (1990), pp. 1612-1618.
44. Bintein, S., Devillers, J., and Karcher, W. ``Nonlinear
Dependence of Fish Bioconcentration on Octanol/Water Partition
Coefficient.'' SAR QSAR Environ. Res. v. 1, (1993), pp. 29-39.
45. Syracuse Research Corporation BCF database for 694 chemicals.
46. USEPA, OW. Great Lakes Water Quality Initiative Technical
Support Document for the Procedure to Determine Bioaccumulation
Factors. EPA-820-B-95-005, March 1995.
47. USEPA/OPPT. Technical Support Document for Determination of
Bioaccumulation (BAF) and Bioconcentration (BCF) Values for Persistent
Bioaccumulative Toxic (PBT) Chemicals and for Identification of PBT
Chemicals. Jerry Smrchek, Ph.D., Biologist, Existing Chemicals
Assessment Branch, Risk Assessment Division. September 1998.
48. Hazardous Substances Data Bank (HSDB) (data base). National
Institutes of Health, National Library of Medicine, Bethesda, MD, USA.
(1995). http://toxnet.nlm.nih.gov
49. Howard, P.H., Sage, G.W., LaMacchia, A., and Colb, A., ``The
Development of an Environmental Fate Database.'' J. Chem. Inf. Comput.
Sci. v. 22, (1982), pp. 38-44.
50. Howard, P.H., et al., ``BIOLOG, BIODEG, and FATE/EXPOS: New
Files on Microbial Degradation and Toxicity as Well as Environmental
Fate/exposure of Chemicals.'' Environ. Toxicol. Chem. v. 5, (1986), pp.
:977-988.
51. Estimating the Hazard of Chemical Substances to Aquatic Life,
Cairns, J., Jr., Dickson, K.L., and Maki, A.W. (eds.). STP 657,
American Society for Testing and Materials, Phila., PA, (1978), 278 pp.
52. Cairns, J., Jr. and Dickson, K.L., ``Ecological Hazard/Risk
Assessment: Lessons Learned and New Directions.'' Hydrobiologia v. 312,
(1995), pp. 87-92.
53. USEPA, OTS. Testing For Environmental Effects Under the Toxic
Substances Control Act. U.S. Environmental Protection Agency, Office of
Toxic Substances, Health and Environmental Review Division,
Environmental Effects Branch, Washington, DC, (1983), 24 pp.
54. USEPA, OTS. Technical Support Document for the Environmental
Effects Testing Scheme. U.S. Environmental Protection Agency, Office of
Toxic Substances, Health and Environmental Review Division,
Environmental Effects Branch, Washington, DC, (1983), 31 pp.
55. Veith, G.D., DeFoe, D.L., and Bergstedt, B.V., ``Measuring and
Estimating the Bioconcentration Factor of Chemicals in Fish.'' J. Fish.
Res. Board Canada v. 36, (1979), pp. 1040-1048.
56. Veith, G.D., Macek, K.J., Petrocelli, S.R., and Carrol, J.,
``An Evaluation of Using Partition Coefficients and Water Solubility to
Estimate Bioconcentration Factors for Organic Chemicals in Fish'' In
Aquatic Toxicology, Eaton, J.G., Parrish, P.R., and Hendricks, A.C.,
(eds.). STP 707, American Society for Testing and Materials, Phila.,
PA. (1980) pp. 116-129.
57. Life Systems, Inc. Testing Triggers Workshop: Workshop Report,
Project 1247, Contract No. 68-01-6554. U.S. Environmental Protection
Agency, Office of Toxic Substances, Washington, DC, (1983), 62 pp.
58. Akerman, J.W. and Coppage, D.L., ``Hazard Assessment
Philosophy: A Regulatory Viewpoint.'' In Analyzing the Hazard
Evaluation Process, Dickson, K.L., Maki, A.W., and Cairns, J., Jr.,
(eds.). Water Quality Section, American Fisheries Society, Washington,
DC., (1979), pp. 68-73.
59. American Institute for Biological Sciences (AIBS). ``Criteria
and Rationale for Decision Making in Aquatic Hazard Evaluation (Third
Draft),'' Aquatic Hazards of Pesticides Task Group of the American
Institute of Biological Sciences. In Estimating the Hazard of Chemical
Substances to Aquatic Life, Cairns, J., Jr., Dickson, K.L., and Maki,
A.W. (eds.). STP 657, American Society for Testing and Materials,
Phila., PA., (1978), pp. 241-273.
60. American Society for Testing and Materials (ASTM). ``Proposed
Working Document for the Development of an ASTM Draft Standard on
Standard Practice for a Laboratory Testing Scheme to Evaluate Hazard to
Non-Target Aquatic Organisms,'' ASTM Subcommittee E35.21 on Safety to
Man and Environment. In Estimating the Hazard of Chemical Substances to
Aquatic Life, Cairns, J., Jr., Dickson, K.L., and Maki, A.W. (eds.),
STP 657, American Society for Testing and Materials, Phila., PA.,
(1978), pp. 202-237.
61. Kimerle, R.A., Gledhill, W.E., and Levinskas, G.J.,
``Environmental Safety Assessment of New Materials,'' In Estimating the
Hazard of Chemical Substances to Aquatic Life, Cairns, J., Jr.,
Dickson, K.L., and Maki, A.W. (eds.) . STP 657, American Society for
Testing and Materials, Phila., PA., (1978), pp. 132-146.
62. Maki, A.W. and Duthie, J.R., ``Summary of Proposed Procedures
for the Evaluation of Aquatic Hazard,'' In Estimating the Hazard of
Chemical Substances to Aquatic Life, Cairns, J., Jr., Dickson, K.L.,
and Maki, A.W. (eds.). STP 657, American Society for Testing and
Materials, Phila., PA., (1978), pp. 153-163.
63. Stern, A.M. and Walker, C.R., ``Hazard Assessment of Toxic
Substances: Environmental Fate Testing of Organic Chemicals and
Ecological Effects Testing,'' In Estimating the Hazard of Chemical
Substances to Aquatic Life, Cairns, J., Jr., Dickson, K.L., and Maki,
A.W. (eds.). STP 657, American Society for Testing and Materials,
Phila., PA. (1978), pp. 81-131.
64. International Joint Commission. A Strategy for the Virtual
Elimination of Persistent Toxic Substances. Vol. 1. Report of the
Virtual Elimination Task Force to the International Joint Commission:
Windsor, Ontario, Canada, 1993.
65. Ontario Ministry of Environment and Energy. Candidate
Substances for Bans, Phase-outs or Reductions - Multimedia Revision.
Ontario, Canada, October 1993.
66. Aronson, D. et.al., Chemical Fate Half-Lives and Persistence
Evaluation for Toxics Release Inventory PBT Rule Chemicals. prepared by
Syracuse Research Corp. for Robert S. Boethling, USEPA Office of
Pollution Prevention and Toxics, Washington, DC. Contract Number
68D50012 Task 451(1998).
67. USEPA, OPPT. Rationale for Classification of Chemicals Crossing
Persistence Categories. prepared by Dave G. Lynch, Economics Exposure
and Technology Division, Office of Pollution Prevention and Toxics,
U.S. Environmental Protection Agency, 401 M St., SW., Washington, DC
20460 (1998).
68. Menzie, C.M., Metabolism of Pesticides Update III. U.S. Fish
and Wildlife Service, Special Scientific Report No. 232 (1980).
69. Lichtenstein, E.P. and Schultz, K.R., ``Epoxidation of Aldrin
and Heptachlor in Soils as Influenced by Autoclaving, Moisture, and
Soil Types.'' J. Econ. Entomol. v. 53(2), (1960), pp. 192-197.
70. Miles, J.R., Tu, C.M., and Harris, C.R., ``Metabolism of
Heptachlor and its Degradation Products by Soil Microorganisms.'' J.
Econ. Entomol. v. 62, (1969), pp. 1332-1338.
71. Carlson, G.P., ``Epoxidation of Aldrin to Dieldrin by
Lobsters.'' Bull.
[[Page 725]]
Environ. Centime. Toxicol. v. 11, (1974), p. 577.
72. Sanborn, J.R., Francis, B.M., Metcalf, R.L., The Degradation of
Selected Pesticides in Soil: a Review of the Published Literature. U.S.
NTIS, PB-272352, (1977), 633 pp.
73. Rosenblatt, D.H. et al.. Appendix K- Aldrin/Dieldrin.
Preliminary assessment of ecological hazards and toxicology of
environmental pollutants at Rocky Mountain Arsenal. (1975).
74. Tu, C.M., Miles, J.R., and Harris, C.R., ``Soil Microbial
Degradation of Aldrin.'' Life Sci. v. 7, (1968), pp. 311-323.
75. IRIS, 1998. U.S. Environmental Protection Agency's Integrated
Risk Information System file pertaining to endrin, dieldrin, and
heptachlor epoxide.
76. Boethling, R.S., EQC Model Output for Toxics Release Inventory
PBT Rule Chemicals. USEPA Office of Pollution Prevention and Toxics,
Washington, DC. Syracuse Research Corp. Contract Number 68D50012 Task
451, (1998).
77. USEPA. Method 23 - Determination of Polychlorinated Dibenzo-p-
Dioxins and Polychlorinated Dibenzofurans from Stationary Sources.
Standards of Performance for New Stationary Sources. 40 CFR Part 60
Appendix A.
78. Safe, S.; ``Polychlorinated Biphenyls, Dibenzo-p-dioxin and
Dibenzofurans and Related Compounds: Environmental and Mechanistic
Considerations Which Support the Development of Toxic Equivalency
Factors.'' CRC Crit. Rev. Toxicol. v. 21, (1990), pp. 51-88.
79. USEPA, OPPT. Economic Analysis of the Proposed Rule to Modify
Reporting of Persistent Bioaccumulative Toxic Chemicals under EPCRA
Section 313, (1998).
80. USSBA. Office of Advocacy - Statistics - Major Industry, Firms,
Establishment, Employment, Payroll and Receipts, 1995. Information from
the Small Business Administration on the Internet. http://www.sba.gov/
advo/stats/us_ind95.html. Downloaded on December 10, 1998.
XII. Regulatory Assessment Requirements
A. Executive Order 12866
Under Executive Order 12866 (58 FR 51735, October 4, 1993), it has
been determined that this is an economically ``significant regulatory
action'' because it is likely to have an annual effect of $100 million
or more. This action therefore was submitted to the Office of
Management and Budget (OMB) for review, and any substantive comments or
changes made during that review have been documented in the public
record.
B. Regulatory Flexibility Act
For the reasons explained in Unit X of this preamble, pursuant to
section 605(b) of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.), the Agency hereby certifies that this proposed rule will not
have a significant economic impact on a substantial number of small
entities. In brief, the factual basis of this determination is as
follows: there are 17 small governments that may be affected by the
proposed rule (i.e., will have to file reports under the proposed
rule), none of which will bear annual costs greater than 1% of annual
government revenues. EPA estimates that 4 of the approximately 3,600
small businesses potentially affected by the proposed rule will
experience annual compliance costs above 1% of annual sales after the
first year of reporting. Given these relatively small estimated
impacts, for purposes of the RFA, EPA believes that the proposed rule
will not have a significant economic impact on a substantial number of
small entities. EPA's estimates are based on the economic analysis
(Ref. 79), and are also discussed in Unit X. of this preamble. This
determination is for the entire population of small entities
potentially affected by this proposed rule, since the test for
certification is whether the rule as a whole has a significant economic
impact on a substantial number of small entities.
Notwithstanding the Agency's certification of this rule under
section 605(b) of the RFA, EPA remains committed to minimizing real
impacts on small entities where this does not unacceptably compromise
the informational benefits of the rule. Although not required, EPA
intends to prepare guidance for reporting on dioxin that will assist
facilities in determining their compliance needs and in properly
completing the form, which will help ensure that small entities receive
assistance to ease their burden of compliance. EPA has prepared such
documents for current reporters and has received positive feedback on
their utility from the targeted facilities. In addition, the Agency is
always interested in any comments regarding the economic impacts that
this regulatory action would impose on small entities, particularly
suggestions for minimizing that impact. Such comments may be submitted
to the Agency at any time, to the address listed above. To ensure
consideration during the development of the final rule, comments must
be received by the data indicated in the ``DATES'' section.
Information relating to this determination has been provided to the
Chief Counsel for Advocacy of the Small Business Administration, and is
included in the docket for this rulemaking.
C. Paperwork Reduction Act
The information collection requirements contained in this proposed
rule have been submitted to OMB under the Paperwork Reduction Act
(PRA), 44 U.S.C. 3501 et seq., and in accordance with the procedures at
5 CFR 1320.11. An Information Collection Request (ICR) document has
been prepared by EPA (EPA ICR No. 1363) and a copy may be obtained from
Sandy Farmer, OPPE Regulatory Information Division; U.S. Environmental
Protection Agency (2137); 401 M St., SW.; Washington, DC 20460, by
calling (202) 260-2740, or electronically by sending an e-mail message
to ``[email protected].'' An electronic copy has also been posted
with this Federal Register document on EPA's homepage with other
information related to this action. The information requirements
contained in this proposal would not become effective until OMB
approves them. An Agency may not conduct or sponsor, and a person is
not required to respond to a collection of information subject to OMB
approval under the PRA unless it displays a currently valid OMB control
number. The OMB control numbers for EPA's regulations, after initial
publication in the Federal Register, are maintained in a list at 40 CFR
part 9.
Provision of this information is mandatory, upon promulgation of a
final rule, pursuant to EPCRA section 313 (42 U.S.C. 11023) and PPA
section 6607 (42 U.S.C. 13106). EPCRA section 313 requires owners or
operators of certain facilities manufacturing, processing, or otherwise
using any of over 600 listed toxic chemicals and chemical categories
(hereinafter toxic chemicals) in excess of the applicable threshold
quantities, and meeting certain requirements (i.e., at least 10 FTEs or
the equivalent), to report environmental releases and transfers of and
waste management activities for such chemicals annually. Under section
6607 of the PPA, facilities must also provide information on the
quantities of the toxic chemicals in waste streams and the efforts made
to manage those waste quantities. The regulations codifying the EPCRA
section 313 reporting requirements appear at 40 CFR part 372.
Respondents may designate the specific chemical identity of a substance
as a trade secret, pursuant to
[[Page 726]]
EPCRA section 322 (42 U.S.C. 11042). Regulations codifying the trade
secret provisions can be found at 40 CFR part 350.
Under the proposed rule, all facilities reporting to TRI on PBT
chemicals would have to use the EPA Toxic Chemical Release Inventory
Form R (EPA Form No. 9350-1). OMB has approved the existing reporting
and recordkeeping requirements related to Form R, supplier
notification, and petitions under OMB Control No. 2070-0093 (EPA ICR
No. 1363).
For Form R, EPA estimates the industry reporting burden for
collecting this information (including recordkeeping) to average 74
hours per report in the first year, at an estimated cost of $5,079 per
Form R. In subsequent years, the burden is estimated to average 52.1
hours per report, at an estimated cost of $3,557 per Form R. These
estimates include the time needed to review instructions; search
existing data sources; gather and maintain the data needed; complete
and review the collection of information; and transmit or otherwise
disclose the information. The actual burden on any specific facility
may be different from this estimate depending on the complexity of the
facility's operations and the profile of the releases at the facility.
This proposed rule is estimated to result in reports from 9,500
respondents. Of these, 2,600 facilities are estimated to be reporting
to TRI for the first time as a result of the rule, while 6,900 are
currently reporting facilities that will be submitting additional
reports. These facilities will submit an estimated additional 17,000
Form Rs. This proposed rule therefore results in an estimated total
burden of 1.8 million hours in the first year, and 1 million hours in
subsequent years, at a total estimated industry cost of $126 million in
the first year and $70 million in subsequent years.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes, where
applicable, the time needed to review instructions; develop, acquire,
install, and utilize technology and systems for the purposes of
collecting, validating, and verifying information, processing and
maintaining information, and disclosing and providing information;
adjust the existing ways to comply with any previously applicable
instructions and requirements; train personnel to be able to respond to
a collection of information; search data sources; complete and review
the collection of information; and transmit or otherwise disclose the
information. EPA's burden estimates for the rule take into account all
of the above elements, considering that under section 313, no
additional measurement or monitoring may be imposed for purposes of
reporting.
Comments are requested on the Agency's need for this information,
the accuracy of the provided burden estimates, and any suggested
methods for minimizing respondent burden, including through the use of
automated collection techniques. Send comments on the ICR to EPA at the
address provided above, with a copy to the Office of Information and
Regulatory Affairs, Office of Management and Budget, 725 17th St., NW.,
Washington, DC 20503, marked ``Attention: Desk Officer for EPA.''
Please remember to include the ICR number in any correspondence. The
final rule will respond to any comments on the information collection
requirements contained in this proposal.
D. Unfunded Mandates Reform Act and Executive Order 12875
Pursuant to Title II of the Unfunded Mandates Reform Act of 1995
(UMRA) (Pub. L. 104-4), EPA has determined that this action contains a
Federal mandate'' that may result in expenditures of $100 million or
more for the private sector in any 1 year, but that it will not result
in such expenditures for State, local, and tribal governments, in the
aggregate. Accordingly, EPA has prepared a written statement for this
proposed rule pursuant to section 202 of UMRA, and that statement is
available in the public docket for this rulemaking. The costs
associated with this action are estimated in the economic analysis
prepared for this proposed rule (Ref. 79), which is included in the
public docket and summarized in Unit X. of this preamble. The following
is a brief summary of the UMRA statement for the proposed rule.
This proposed rule is being promulgated pursuant to sections
313(b)(1)(B) and (d) of EPCRA, 42 U.S.C. section 11023(b)(1)(B) and
(d), and section 6607 of the Pollution Prevention Act, 42 U.S.C.
section 13106. The economic analysis contains an analysis of the
benefits and costs of this proposed rule, which estimates that the
total industry costs of the proposed rule will be $126 million in the
first year and $70 million per year thereafter, and concludes that the
benefits will be significant but cannot be assigned a dollar value due
to the lack of adequate methodologies. This information is also
summarized above in Unit X of this preamble. EPA believes that the
benefits provided by the information to be reported under this proposed
rule will significantly outweigh the costs imposed by today's action.
The benefits of the information will in turn have positive effects on
health, safety, and the natural environment through the behavioral
changes that may result from that information.
EPA has not identified any Federal financial resources that are
available to cover the costs of this proposed rule. As set forth in the
economic analysis, EPA has estimated the future industry compliance
costs (after the first year) of this proposed rule to be $70 million
annually. Of those entities affected by today's action, EPA has not
identified any disproportionate budgetary impact on any particular
region, government, or community, or on any segment of the private
sector. Based on the economic analysis, EPA has concluded that it is
highly unlikely that this proposed rule will have an appreciable effect
on the national economy.
EPA has determined that it is not required to develop a small
government agency plan as specified by section 203 of UMRA or to
conduct prior consultation with State, local, or tribal governments
under section 204 of UMRA, because the proposed rule will not
significantly or uniquely affect small governments and does not contain
a significant Federal intergovernmental mandate.
Finally, EPA believes this proposed rule complies with section
205(a) of UMRA. The objective of this proposed rule is to expand the
public benefits of the TRI program by exercising EPA's discretionary
authority to add chemicals to the program and to lower reporting
thresholds, thereby increasing the amount of information available to
the public regarding the use, management and disposition of listed
toxic chemicals. In making additional information available through
TRI, the Agency increases the utility of TRI data as an effective tool
for empowering local communities, the public sector, industry, other
agencies, and State and local governments to better evaluate risks to
public health and the environment, particularly at the local level.
As described in Unit VII.A.1.ii. of this preamble, EPA considered
burden in the threshold selection. The rule also contains reporting
requirements that will limit burden (e.g., reporting limitations for
vanadium in alloys and a ``manufacture only'' activity qualifier for
dioxin). In addition, existing burden-reducing measures (e.g., the
laboratory exemption, and the otherwise use exemptions, which include
the routine
[[Page 727]]
janitorial or facility grounds maintenance exemption, motor vehicle
maintenance exemption, structural component exemption, intake air and
water exemption and the personal use exemption) will apply to the
facilities that file new reports as a result of this proposed rule. EPA
also will be assisting small entities subject to the proposed rule, by
such means as providing meetings, training, and compliance guides in
the future, which also will ease the burdens of compliance.
Many steps have been and will be taken to further reduce the burden
associated with this proposed rule, and to EPA's knowledge there is no
available alternative to the proposed rule that would obtain the
equivalent information in a less burdensome manner. For all of these
reasons, EPA believes the rule complies with UMRA section 205(a).
E. Executive Orders 12898 and 13045
Pursuant to Executive Order 12898 (59 FR 7629, February 16, 1994),
entitled ``Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations,'' the Agency must consider
environmental justice related issues with regard to the potential
impacts of this action on environmental and health conditions in low-
income populations and minority populations. Pursuant to Executive
Order 13045 (62 FR 19885, April 23, 1997), entitled ``Protection of
Children from Environmental Health Risks and Safety Risks,'' if an
action is economically significant under Executive Order 12866, the
Agency must, to the extent permitted by law and consistent with the
agency's mission, identify and assess the environmental health risks
and safety risks that may disproportionately affect children.
By lowering the section 313 reporting thresholds for PBT chemicals,
EPA is providing communities across the United States (including low-
income populations and minority populations) with access to data that
may assist them in lowering exposures and consequently reducing
chemical risks for themselves and their children. This information can
also be used by government agencies and others to identify potential
problems, set priorities, and take appropriate steps to reduce any
potential risks to human health and the environment. Therefore, the
informational benefits of the proposed rule will have a positive impact
on the human health and environmental impacts of minority populations,
low-income populations, and children.
List of Subjects in 40 CFR Part 372
Environmental protection, Community right-to-know, Reporting and
recordkeeping requirements, and Toxic chemicals.
Dated: December 24, 1998.
Carol M. Browner,
Administrator.
Therefore, it is proposed that 40 CFR part 372 be amended as
follows:
PART 372--[AMENDED]
1. The authority citation for part 372 would continue to read as
follows:
Authority: 42 U.S.C. 11023 and 11048.
Sec. 372.22 [Amended]
2. In Sec. 372.22(c), by removing the phrase ``Sec. 372.25 or
Sec. 372.27.'' and adding in its place ``Sec. 372.25, Sec. 372.27, or
Sec. 372.28.''
Sec. 372.25 [Amended]
3. In the introductory text of Sec. 372.25, by removing the first
clause ``Except as provided in Sec. 372.27,'' and adding in its place
``Except as provided in Sec. 372.27 and Sec. 372.28,''.
4. In Sec. 372.27, by adding a new paragraph (e) to read as
follows:
Sec. 372.27 Alternate threshold and certification.
* * * * *
(e) The provisions of this section do not apply to any chemicals
listed in Sec. 372.28.
5. By adding a new Sec. 372.28 to subpart B to read as follows:
Sec. 372.28 Lower thresholds for chemicals of special concern.
(a) Notwithstanding Sec. 372.25 or Sec. 372.27, for the toxic
chemicals set forth in this section, the threshold amounts for
manufacturing (including importing), processing, and otherwise using
such toxic chemicals are as set forth in this section.
(1) Chemical listing in alphabetic order.
------------------------------------------------------------------------
Reporting
Chemical name CAS No. threshold
------------------------------------------------------------------------
Aldrin.......................... 00309-00-2 100
Benzo(g,h,i)perylene............ 00191-24-2 10
Chlordane....................... 00057-74-9 10
Dicofol......................... 00115-32-2 10
Heptachlor...................... 00076-44-8 10
Hexachlorobenzene............... 00118-74-1 10
Isodrin......................... 00465-73-6 10
Mercury......................... 07439-97-6 10
Methoxychlor.................... 00072-43-5 100
Octachlorostyrene............... 29082-74-4 10
Pendimethalin................... 40487-42-1 100
Pentachlorobenzene.............. 00608-93-5 10
Polychlorinated Biphenyl (PCBs). 01336-36-3 10
Tetrabromobisphenol A........... 00079-94-7 100
Toxaphene....................... 08001-35-2 10
Trifluralin..................... 01582-09-8 100
------------------------------------------------------------------------
(2) Chemical categories in alphabetic order.
------------------------------------------------------------------------
Category name Reporting threshold
------------------------------------------------------------------------
Dioxin and Dioxin-Like Compounds 0.1 grams
(manufacture only): (This category
includes only those chemicals listed
below).
67562-39-4 1,2,3,4,6,7,8-
Heptachlorodibenzofuran
55673-89-7 1,2,3,4,7,8,9-
Heptachlorodibenzofuran
70648-26-9 1,2,3,4,7,8-
Hexachlorodibenzofuran
57117-44-9 1,2,3,6,7,8-
Hexachlorodibenzofuran
72918-21-9 1,2,3,7,8,9-
Hexachlorodibenzofuran
60851-34-5 2,3,4,6,7,8-
Hexachlorodibenzofuran
39227-28-6 1,2,3,4,7,8-
Hexachlorodibenzo-p-dioxin
57653-85-7 1,2,3,6,7,8-
Hexachlorodibenzo-p-dioxin
19408-74-3 1,2,3,7,8,9-
Hexachlorodibenzo-p-dioxin
35822-46-9 1,2,3,4,6,7,8-
Heptachlorodibenzo-p-dioxin
39001-02-0 1,2,3,4,6,7,8,9-
Octachlorodibenzofuran
03268-87-9 1,2,3,4,6,7,8,9-
Octachlorodibenzo-p-dioxin
57117-41-6 1,2,3,7,8-
Pentachlorodibenzofuran
57117-31-4 2,3,4,7,8-
Pentachlorodibenzofuran
40321-76-4 1,2,3,7,8-
Pentachlorodibenzo-p-dioxin
[[Page 728]]
51207-31-9 2,3,7,8-
Tetrachlorodibenzofuran
01746-01-6 2,3,7,8-Tetrachlorodibenzo-
p-dioxin
Mercury compounds......................... 10
Polycyclic aromatic compounds (PACs): 10
(This category includes only those
chemicals listed below).
00056-55-3 Benz(a)anthracene
00205-99-2 Benzo(b)fluoranthene
00205-82-3 Benzo(j)fluoranthene
00207-08-9 Benzo(k)fluoranthene
00206-44-0 Benzo(j,k)fluorene
00189-55-9 Benzo(r,s,t)pentaphene
00218-01-9 Benzo(a)phenanthrene
00050-32-8 Benzo(a)pyrene
00226-36-8 Dibenz(a,h)acridine
00224-42-0 Dibenz(a,j)acridine
00053-70-3 Dibenzo(a,h)anthracene
00194-59-2 7H-Dibenzo(c,g)carbazole
05385-75-1 Dibenzo(a,e)fluoranthene
00192-65-4 Dibenzo(a,e)pyrene
00189-64-0 Dibenzo(a,h)pyrene
00191-30-0 Dibenzo(a,l)pyrene
00057-97-6 7,12-
Dimethylbenz(a)anthracene
00193-39-5 Indeno[1,2,3-cd]pyrene
00056-49-5 3-Methylcholanthrene
03697-24-3 5-Methylchrysene
05522-43-0 1-Nitropyrene
------------------------------------------------------------------------
(b) The threshold determination provisions at Sec. 372.25(c)-(h)
and the exemptions at Sec. 372.38(b)-(h) are applicable to the toxic
chemicals listed in paragraph (a) of this section.
Sec. 372.30 [Amended]
6. In Sec. 372.30(a), by removing the phrase ``in Sec. 372.25 at''
and adding in its place ``in Sec. 372.25, Sec. 372.27, or Sec. 372.28
at''.
7. In Sec. 372.38(a), by adding the following sentence at the end
of the paragraph to read as follows:
Sec. 372.38 Exemptions.
(a) * * * This exemption does not apply to toxic chemicals
listed in Sec. 372.28, except for purposes of Sec. 372.45(d)(1).
* * * * *
8. In Sec. 372.65,
i. By removing in paragraph (a) the entry ``Vanadium (fume or
dust)'' and adding in its place ``Vanadium (except when contained in an
alloy)''.
ii. By removing in paragraph (b) for CAS no. 7440-62-2, the entry
``Vanadium (fume or dust)'' and adding in its place ``Vanadium (except
when contained in an alloy)''.
iii. By adding chemicals to paragraph (a) alphabetically.
iv. By adding chemicals to paragraph (b) by CAS no. sequence.
v. By adding two categories to paragraph (c) alphabetically.
vi. By adding two chemicals to paragraph (c) under the polycyclic
aromatic compounds (PACs) category.
The amendments and additions read as follows:
Sec. 372.65 Chemicals and chemical categories to which the part
applies.
* * * * *
(a) * * *
------------------------------------------------------------------------
Chemical name CAS No. Effective date
------------------------------------------------------------------------
* * * * * * *
Benzo(g,h,i)perylene 00191-24-2 1/00
* * * * * * *
Octachlorostyrene 29082-74-4 1/00
* * * * * * *
Pentachlorobenzene 00608-93-5 1/00
* * * * * * *
Tetrabromobisphenol A 00079-94-7 1/00
* * * * * * *
------------------------------------------------------------------------
(b) * * *
------------------------------------------------------------------------
CAS No. Chemical name Effective date
------------------------------------------------------------------------
* * * * * * *
00079-94-7 Tetrabromobispheno 1/00
l A.
* * * * * * *
00191-24-2 Benzo(g,h,i)peryle 1/00
ne.
[[Page 729]]
* * * * * * *
00608-93-5 Pentachlorobenzene 1/00
* * * * * * *
29082-74-4 Octachlorostyrene. 1/00
* * * * * * *
------------------------------------------------------------------------
(c) * * *
------------------------------------------------------------------------
Category name Effective date
------------------------------------------------------------------------
* * * * * * *
Dioxin and Dioxin-Like Compounds (manufacture only):
(This category includes only those chemicals listed
below).............................................. 1/00
67562-39-4 1,2,3,4,6,7,8-Heptachlorodibenzofuran
55673-89-7 1,2,3,4,7,8,9-Heptachlorodibenzofuran
70648-26-9 1,2,3,4,7,8-Hexachlorodibenzofuran
57117-44-9 1,2,3,6,7,8-Hexachlorodibenzofuran
72918-21-9 1,2,3,7,8,9-Hexachlorodibenzofuran
60851-34-5 2,3,4,6,7,8-Hexachlorodibenzofuran
39227-28-6 1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin
57653-85-7 1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin
19408-74-3 1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin
35822-46-9 1,2,3,4,6,7,8-Heptachlorodibenzo-p-
dioxin
39001-02-0 1,2,3,4,6,7,8,9-Octachlorodibenzofuran
03268-87-9 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-
dioxin
57117-41-6 1,2,3,7,8-Pentachlorodibenzofuran
57117-31-4 2,3,4,7,8-Pentachlorodibenzofuran
40321-76-4 1,2,3,7,8-Pentachlorodibenzo-p-dioxin
51207-31-9 2,3,7,8-Tetrachlorodibenzofuran
01746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin
* * * * * * *
Polycyclic aromatic compounds (PACs): This category
includes only those chemicals listed below).........
* * * * * * *
00206-44-0 Benzo(j,k)fluorene 1/00
* * * * * * *
00056-49-5 3-Methylcholanthrene 1/00
* * * * * * *
Vanadium compounds 1/00
* * * * * * *
------------------------------------------------------------------------
Sec. 372.85 [Amended]
9. In Sec. 372.85,
i. By removing in paragraphs (b)(15)(i) introductory text and
(b)(16)(ii)(B) the phrase ``may be indicated in ranges'' and adding in
its place ``may be indicated in ranges, except for chemicals set forth
in Sec. 372.28''.
ii. By removing in paragraph (b)(16)(i)(B) the phrase ``may be
indicated as a range'' and adding in its place ``may be indicated as a
range, except for chemicals set forth in Sec. 372.28''.
[FR Doc. 98-34835 Filed 12-30-98; 4:17 pm]
BILLING CODE 6560-50-F