[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]



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Part VI





Environmental Protection Agency





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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.

-----------------------------------------------------------------------

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

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``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.

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    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

[[Page 693]]

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

[[Page 694]]

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,

[[Page 696]]

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

[[Page 697]]

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 
States Strategy for the Virtual Elimination of Persistent Toxic 
Substances in the Great Lakes, signed by Carol Browner, Administrator 
U.S. Environmental Protection Agency and Sergio Marchi, Minister of the 
Environment Government of Canada. 1997.
    2. USEPA, OPPT. Support Document for the Addition of Certain 
Chemicals to Section 313 of the Emergency Planning and Community Right-
to-Know Act. U.S. Environmental Protection Agency, Washington DC 
(1998).
    3. USEPA, OSWER. Waste Minimization Prioritization Tool Beta Test 
Version 1.0 User's Guide and System Documentation (Draft). Appendix D 
Draft Prioritized Chemical List. U.S. Environmental Protection Agency, 
Washington DC, EPA530-R-97-019, June 1997.
    4. Atkinson, R., ``Kinetics and Mechanisms of the Gas-Phase 
Reactions of the Hydroxyl Radical with Organic Compounds.'' J. Phys. 
Chem. Ref. Data Monograph No. 1 1989.
    5. Webster, E., Mackay, D. and F Wania, F, ``Evaluating 
Environmental Persistence.'' Environ. Toxicol. Chem., in press (1998).
    6. Anderson, P.N. and RA Hites, R.A., ``OH Radical Reactions: The 
Major Removal Pathway for Polychlorinated

[[Page 723]]

Biphenyls in the Atmosphere.'' Environ. Sci. Technol. v. 30, (1996), 
pp. 1756-1763.
    7. Altshuller, A.P., ``Ambient Hydroxyl Radical Concentration: 
Measurements and Model Predictions.'' J. Air Pollut. Contr. Assoc. v. 
39, (1989), pp. 704-708.
    8. Ngabe, B., Bidleman, T.F., and Falconer, R.L., ``Base Hydrolysis 
of Alpha- and Delta-hexachlorocyclohexane.'' Environ. Sci. Technol. v. 
27, (1993), pp. 1930-1933.
    9. Vink, J.P.M. and Van Der Zee, E.A.T.M., ``Pesticide 
Biotransformation in Surface Waters: Multivariate Analyses of 
Environmental Factors at Field Sites.'' Water Res. v. 31, (1997), pp. 
2858-2868.
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Lindane in the Aquatic Environment: Rate Constants of Physical and 
Chemical Processes.'' Environ. Toxicol. Chem. v. 1, (1982), pp. 289-
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    11. Meylan, W.M. and Howard, P.H., ``Computer Estimation of the 
Atmospheric Gas-phase Reaction of Organic Compounds with Hydroxyl 
Radicals and Ozone.'' Chemosphere v. 26, (1993), pp. 2293-2299.
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Structure-reactivity Relationship: an Update.'' Atmos. Environ. v. 29, 
(1995), pp. 1685-1695.
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M.E., ``Factors for Intermedia Extrapolation in Biodegradability 
Assessment.'' Chemosphere v. 30, (1995), pp. 741-752.
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Mineralization Rates from the Ready CO2 Screening Test to Activated 
Sludge, River Water and Soil.'' Environ. Toxicol. Chem. v. 16, (1997), 
pp. 127-134.
    15. USEPA, OPPT. Persistent, Bioaccumulative Substances on the 
Toxics Release Inventory (TRI): Report on Persistence Screening 
Criteria. Boethling, R. S., U.S. Environmental Protection Agency. 
(September 4, 1997).
    16. USEPA, OW. Bioaccumulation Testing and Interpretation for the 
Purpose of Sediment Quality Assessment: a White Paper. First draft, 
dated July 1996. Report prepared for the USEPA Bioaccumulation Analysis 
Workgroup. Prepared for the USEPA Office of Water.
    17. ICF Incorporated. Focus Chemicals for the Clean Air Act 
Amendments Great Waters Study. Draft report, dated 15 Aug 1991. 
Prepared for the USEPA Office of Air Quality Planning and Standards.
    18. Clements, R.G., Boethling, R.S., Zeeman, M., and Auer, C.M., 
``Persistent Bioaccumulative Chemicals: Screening the TSCA Inventory.'' 
Paper presented at the SETAC Foundation workshop ``Environmental Risk 
Assessment for Organochlorine Chemicals,'' July 24-29, 1994, 
Nottawasaga Inn, Alliston, ON, Canada.
    19. Environment Canada. Towards a Toxic Substances Management 
Policy for Canada: A Discussion Document. September 1994.
    20. Rodan, B. and Eckley, N., Science-Policy Assessment of POPs 
Screening Criteria: Report to the U.S. EPA International Toxics 
Coordinating Committee. Draft report dated August 21, 1997.
    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.
    22. UNECE-LRTAP. Draft Composite Negotiating Text for a Protocol on 
Persistent Organic Pollutants. United Nations Economic Commission for 
Europe. EB.AIR/WG.5/R.72, March 10, 1997.
    23. CMA. PTB Policy Implementation Guidance. Product Risk 
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