[Federal Register Volume 63, Number 216 (Monday, November 9, 1998)]
[Notices]
[Pages 60332-60343]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-29952]


=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

[FRL-6186-7]


Notice of Availability of Draft RCRA Waste Minimization PBT 
Chemical List

AGENCY: Environmental Protection Agency.

ACTION: Notice of data availability.

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

SUMMARY: Today's notice makes available for public comment a list of 53 
persistent, bioaccumulative, and toxic (PBT) chemicals and chemical 
categories which may be found in hazardous wastes regulated under the 
Resource Conservation and Recovery Act (RCRA). This notice responds to 
States, industry organizations, environmental groups, and individuals 
who commented on the EPA's national RCRA waste minimization policy, and 
it will be used to promote voluntary waste minimization efforts which 
reduce the generation of PBT chemicals found in RCRA hazardous waste by 
at least half by the year 2005.
    EPA requests comment on today's RCRA Waste Minimization PBT 
Chemical List (also referred to as the RCRA PBT List) and the 
methodology used to develop today's List. EPA is not seeking comment on 
the Waste Minimization Prioritization Tool (WMPT), which is discussed 
in today's notice, because the Agency has sought extensive public 
review and comment on the WMPT in a previous notice. Particular issues 
for comment are identified in the discussion that follows.
    EPA will publish a final RCRA PBT List in 1999. This notice and the 
final RCRA PBT List are a significant component of an overall PBT 
strategy being developed by Agency. The overall strategy will encompass 
the PBT priorities and programs identified by other EPA offices, 
particularly those that cannot be addressed by single media controls 
and approaches.

DATES: Please submit written comments by January 8, 1999 to the address 
below.

TO OBTAIN COPIES: Copies of the draft list and all documents cited in 
this notice can be obtained by calling the RCRA/Superfund/CERCLA 
Hotline at (800) 424-9346, TDD (800) 553-7672 (hearing impaired), or 
(703) 412-9810 in the Washington, DC metropolitan area, from 9:00 a.m. 
until 6:00 p.m. Eastern time.
    The draft list and supporting documents are also available in 
electronic format on the Internet, and can be obtained by accessing:

WWW: http://www.epa.gov/wastemin
FTP: ftp.epa/gov
Login: anonymous

[[Page 60333]]

Password: your Internet address

TO SUBMIT COMMENTS: Please send an original and two copies of comments, 
referencing docket number F-98-MMLP-FFFFF, to: RCRA Docket Information 
Center, Office of Solid Waste (5305G), U.S. Environmental Protection 
Agency Headquarters (EPA, HQ), 401 M Street, SW, Washington, DC 20460. 
Hand deliveries of comments should be made to the Arlington, VA, 
address provided below. Comments may also be submitted electronically 
by sending electronic mail through the Internet to: rcra-
[email protected]. Comments in electronic format should also be 
identified by the docket number F-98-MMLP-FFFFF. All electronic 
comments must be submitted as an ASCII file that contains no special 
characters or any form of encryption.
    Commenters should not submit electronically any confidential 
business information (CBI). CBI submissions must be sent under separate 
cover, and must include an original and two copies. CBI must be 
addressed to: RCRA CBI Document Control Officer, Office of Solid Waste 
(5305W), U.S. EPA, 401 M Street SW, Washington, DC 20460.
    Public comments (not including CBI) and supporting materials are 
available for viewing in the RCRA Information Center (RIC), located at 
Crystal Gateway I, First Floor, 1235 Jefferson Davis Highway, 
Arlington, VA. The RIC is open from 9 a.m. to 4 p.m., Monday through 
Friday, excluding federal holidays. To review docket materials, it is 
recommended that the public make an appointment by calling (703) 603-
9230. The public may copy a maximum of 100 pages from any regulatory 
docket at no charge. Additional copies cost $0.15/page.

FOR FURTHER INFORMATION CONTACT: For further information on waste 
minimization, specific aspects of this notice, or public meetings 
regarding this notice, contact the RCRA/Superfund/EPCRA Hotline at the 
address and telephone numbers cited above, or Newman Smith at the U.S. 
Environmental Protection Agency, Office of Solid Waste, Waste 
Minimization Branch, 401 M Street, SW (5302W), Washington, DC 20460; 
telephone: (703) 308-8757, fax: (703) 308-8433.

SUPPLEMENTARY INFORMATION:

I. Background

A. Why Is EPA Taking This Action?

    EPA regulates thousands of chemicals and wastes under its multiple 
environmental authorities, and has worked with States, the regulated 
community, environmental groups, and individuals to make significant 
progress in controlling harmful chemical releases to the environment. 
Notwithstanding this important progress, recent national and 
international attention has focused on persistent, bioaccumulative and 
toxic (PBT) chemicals which can pose long-term problems when released 
to the environment. Today's notice focuses national attention on 
identifying ways to reduce the generation of PBT chemicals which may be 
found in hazardous wastes regulated under RCRA.
    Today's notice provides a mechanism for implementing the national 
waste minimization policy of RCRA--to reduce or eliminate the 
generation of hazardous waste, wherever feasible, and as expeditiously 
as possible. This national policy sets a clear preference for source 
reduction and recycling methods over end-of-pipe waste treatment and 
disposal methods to reduce releases of harmful chemicals to the 
environment. In 1988, the General Accounting Office (GAO) encouraged 
EPA to focus on reducing the toxicity as well as the volume of 
hazardous waste, and recommended that EPA ``establish specific, 
quantifiable waste minimization goals.1 ''
---------------------------------------------------------------------------

    \1\ New Approach Needed to Manage the Resource Conservation and 
Recovery Act; p. 57; United States General Accounting Office Report 
to Congress; July 1988.
---------------------------------------------------------------------------

    Congress expanded this national policy in the Pollution Prevention 
Act of 1990, and in Clean Air Act amendments of 1990. As Congress 
stated in the Pollution Prevention Act, ``there are significant 
opportunities for industry to reduce or prevent pollution at the source 
through cost effective changes in production, operation, and raw 
materials use. Such changes offer industry substantial savings in 
reduced raw material, pollution control, and liability costs as well as 
help protect the environment and reduce risks to worker health and 
safety.'' The Clean Air Act promotes pollution prevention as a national 
goal, and includes pollution prevention as an important element in 
setting and achieving industrial emissions control standards.
    EPA recognizes that progress has been made in reducing volumes of 
hazardous wastes. However, today's notice expands EPA's focus to 
reducing the toxicity of hazardous wastes, in addition to the volume, 
by reducing RCRA PBT chemical generation at the source, rather than 
relying on reducing the volume and/or toxicity of hazardous waste 
through waste treatment alone. This ``PBT chemical'' approach, which is 
now being addressed at the international level, recognizes that small 
releases of PBT chemicals, even releases that are in compliance with 
existing regulations, may nevertheless cause a build up of human health 
or ecological problems over the long term.
    Today's notice also responds to extensive comments EPA received 
from industry organizations, environmental groups, government agencies, 
and individuals during stakeholder meetings held during 1993 and 1994 
to develop RCRA's Waste Minimization National Plan. Six principles for 
reducing hazardous waste generation on a national level emerged from 
those discussions:
     Focus on source reduction as the preferred means of 
environmental management, and recycling as the second preference, over 
treatment and disposal of hazardous wastes;
     Set environmental priorities based on risk;
     Focus on reducing the chemical composition of hazardous 
waste, not the volume of hazardous wastes, and carefully consider the 
interrelationships between hazardous waste reduction and the reduction 
of toxic releases to air and water;
     Set environmental goals for source reduction and recycling 
of priority chemicals, and track progress toward these goals. Promote 
accountability and recognition for regulated companies, government 
agencies, and other stakeholders involved in the process;
     Provide flexibility to industry and States in the 
selection of chemical priorities, goals for source reduction and 
recycling of priority chemicals, and in selecting approaches for 
achieving source reduction and recycling goals; and
     Involve the public.
    As a result of these discussions, EPA published the Waste 
Minimization National Plan 2 (WMNP), which commits the 
Agency to implementing a national waste minimization program centered 
around these principles. Most importantly, the WMNP sets national goals 
to:
---------------------------------------------------------------------------

    \2\ Waste Minimization National Plan, US EPA, 1994. EPA530-R-94-
045.
---------------------------------------------------------------------------

     Reduce, as a nation, the presence of the most persistent, 
bioaccumulative, and toxic (PBT) chemicals in RCRA hazardous wastes 10% 
by the year 2000, and at least 50 percent by the year 2005 (from a 1991 
baseline);
     Promote source reduction (and recycling where RCRA PBT 
chemicals can not be reduced at the source) over treatment and disposal 
technologies; and

[[Page 60334]]

     Avoid the transfer of RCRA PBT chemicals across 
environmental media.
    EPA believes today's notice provides a strong foundation for 
achieving these goals. The next section describes more specifically how 
EPA, State governments, industry organizations, environmental groups 
and citizens may participate in achieving these goals.

B. What Are Persistent, Bioaccumulative, and Toxic (PBT) Chemicals, and 
Why Are They an Environmental Concern?

    PBT chemicals exhibit varying degrees of three properties: 
Persistent (P) chemicals do not readily break down in the environment; 
bioaccumulative (B) chemicals are not easily metabolized and can 
accumulate in human or ecological foodchains through consumption or 
uptake; toxic (T) chemicals may be hazardous to human health or the 
environment in a variety of ways, depending on the chemical and the 
organism that is exposed. Examples of toxic effects include cancer and 
birth defects in humans and reduced populations and altered community 
structures within ecosystems. Individual chemicals may exhibit none, 
some, or all of these characteristics. Chemicals which exhibit PBT 
characteristics, once released to the environment, may present 
increasing long-term toxic effects to human health and the environment, 
even when these chemicals are released in small quantities.
    RCRA PBT chemicals could be released to the environment from 
several types of sources, including: Leaks from hazardous waste 
treatment, storage or disposal units, authorized releases of PBTs in 
treated hazardous wastes (e.g., combustion emissions or residues which 
must be treated to levels which minimize threats to human health and 
the environment prior to land disposal), or the combined effect of de 
minimis releases of PBT chemicals permitted under multiple permitting 
authorities. Because of the potential risks posed by these chemicals, 
the international community recognizes the chemicals as a global 
environmental concern. EPA is creating a priority in its hazardous 
waste minimization program for these chemicals.

C. How Will EPA and Other Stakeholders Use the RCRA PBT List?

    EPA will use the RCRA PBT List to:
     Measure progress toward the national goal of reducing the 
generation of RCRA PBT chemicals by at least half by the year 2005. EPA 
will measure progress using data reported to the national Toxics 
Release Inventory (TRI) and other nationally available data;
     Report national progress on a periodic basis;
     Identify and acknowledge industrial sectors which 
contribute to national progress; and
     Promote coordinated waste minimization programs at the 
Federal, State, and local level.
    EPA's 1986 Waste Minimization Report to Congress 3 
concluded that promoting voluntary (rather than mandatory) waste 
minimization mechanisms would be the most effective means of reducing 
the volume and/or toxicity of RCRA regulated hazardous waste stream 
generation. Therefore, EPA will rely on voluntary activities to promote 
the reductions of RCRA PBT chemicals in hazardous waste, recognizing 
that some voluntary activities may ultimately take place in conjunction 
with a regulatory activity (e.g., voluntarily implementing pollution 
prevention measures to meet permit compliance requirements).
---------------------------------------------------------------------------

    \3\ Minimization of Hazardous Waste Report to Congress, October 
1986, EPA-530-SW-86-033.
---------------------------------------------------------------------------

    EPA will use the TRI as its primary source of data to measure and 
evaluate progress toward the national goal of reducing the presence of 
PBT chemicals in RCRA hazardous wastes by at least half by 2005. The 
BRS will be used to provide supplemental information and analysis. As 
discussed further below, the method for reporting progress is under 
development, and will build on the method described in today's notice 
for estimating the presence of PBT chemicals in RCRA hazardous wastes.
    EPA is committing to its national RCRA PBT reduction goal to meet 
the requirements of the Government Performance and Results Act (GPRA). 
The GPRA sets government-wide requirements to improve performance of 
government programs by ``managing for results'' and linking 
programmatic budgets to performance. EPA believes its effort to reduce 
long term human health and ecological problems by reducing the 
generation of RCRA related PBT chemicals at the source is a crucial 
GPRA goal.
    EPA will work with interested States, industry organizations, 
environmental groups, and citizens to promote a variety of source 
reduction opportunities and programs which reduce the generation of 
RCRA PBT chemicals at the source. For example, during informal 
discussions, some States, companies, citizens, and other interested 
parties indicated they could use the RCRA PBT List as a guide for 
setting waste minimization priorities for wastes which are currently 
treated or disposed. Government agencies could use the List as a 
starting point to identify industrial sectors or particular chemicals 
for focusing voluntary pollution prevention technical assistance 
resources. Industry trade associations or individual companies could 
use the list for setting waste minimization priorities and reducing 
waste management costs. Individual organizations or a consortium of 
organizations could use the RCRA PBT list to develop Project XL 
proposals in cases where significant reductions in the generation of 
RCRA PBT chemicals are possible, but regulatory flexibility is needed 
to achieve the reductions (information on Project XL is available on 
the Internet at www.epa.gov/projectxl). Citizen groups might use the 
RCRA PBT list to promote pollution prevention as a preferred 
environmental solution over waste treatment or disposal at siting 
hearings or other public comment or waste management forums.
    EPA will also report national progress toward meeting national 
goals publicly, on a periodic basis, to encourage accountability.

D. How Will EPA Measure Progress Toward the National RCRA Hazardous 
Waste PBT Reduction Goal?

    EPA is considering several alternatives for developing a national 
RCRA hazardous waste PBT chemical reduction measurement method. One of 
the key factors in developing a measurement method is the selection of 
an appropriate national database for reporting, storing and retrieving 
data on PBT chemicals found in RCRA hazardous waste. EPA considered, 
among others, two widely used national databases, the RCRA hazardous 
waste Biennial Reporting System (BRS) and the Toxics Release Inventory 
(TRI), and selected the TRI as the primary database for measuring 
national PBT chemical reductions in hazardous waste. The TRI is a 
publicly accepted and widely used source of data on toxic chemicals 
being used, manufactured, treated, transported, and/or released to the 
environment. TRI reports information on specific chemicals which may be 
contained in waste. Using chemical-specific TRI information enables EPA 
to measure reductions of chemical quantities found in wastes over time. 
In contrast, the Biennial Reporting System provides information on 
waste stream volumes, rather than chemical specific data, and will be 
used for supplemental analysis in cases for chemicals which are on the 
RCRA PBT List, but which are not reported in the TRI.

[[Page 60335]]

    The measurement method will include only those facilities which 
report data to the TRI data, and who are also RCRA hazardous waste 
generators. EPA will publish and seek public comment on its draft 
measurement method in 1999.
    EPA will submit national interim progress reports as part of its 
environmental performance reporting under the Government Performance 
and Results Act. A final national progress report will be submitted for 
the year 2005.

E. How Will EPA Encourage Progress Toward the National RCRA PBT 
Reduction Goals?

    EPA will work with States, industry, environmental groups and other 
stakeholders to identify and implement a variety of implementation 
approaches, including workshops, technical assistance, progress 
reporting, partnership agreements, and regulatory reinvention and pilot 
projects, to promote progress toward the national RCRA PBT reduction 
goal. To encourage stakeholder input, EPA will conduct public meetings 
to listen to stakeholder comments on the List and on technical and 
programmatic measures which could be used to reduce the generation of 
PBT chemicals. Information regarding public meetings can be obtained by 
contacting Newman Smith by phone at (703) 308-8757, or on the Internet 
at [email protected]. EPA will combine the efforts of these 
interested parties into a draft national RCRA PBT reduction 
implementation strategy in mid-1999. EPA will solicit public comment on 
the draft strategy and will publish a final implementation strategy 
later in 1999.
    After publication of the final implementation strategy, EPA will 
continue to work with interested parties to promote and document source 
reduction and recycling successes, and measure and report progress, as 
stated above.

F. How is Today's RCRA PBT List Different From Other Chemical Lists?

    Today's draft RCRA PBT list differs from other lists, including 
those used in the RCRA program, because of its purpose and design. 
Today's draft RCRA PBT list:
     Focuses on reducing RCRA PBT chemicals at the point of 
generation, before they are stored, transported, treated, recycled, or 
disposed on the land. Other regulatory lists are often used to set 
treatment technology standards, or concentration based limits on 
chemicals after treatment;
     Focuses on long-term human health and ecological problems, 
rather than more short term or acute human health or ecological 
effects.
     Will be used as a voluntary guide for identifying national 
waste minimization priorities and measuring national reduction 
progress, and may be used flexibly by other government agencies and 
companies. It is not a regulatory list that must be adhered to by all 
stakeholders.
    The basis for developing the RCRA PBT list is explained in the 
following sections of this notice.

G. Why Focus on the Reduction of RCRA PBT Wastes at the Point of 
Hazardous Waste Generation Rather Than After Treatment?

    Nearly all of the regulations promulgated under the RCRA program 
set standards for safe management or cleanup of hazardous wastes after 
they are generated or managed. To meet these standards, the regulated 
community has frequently used ``end-of-pipe'' treatment and control 
technologies. Significant progress has been made using ``end-of-pipe'' 
technologies, even though the costs are significant, and they do not 
completely eliminate releases of toxic chemicals to the environment.
    To address these issues, government agencies and the regulated 
community have increased their focus on the use of source reduction and 
recycling measures in place of, or as a supplement to, end-of-pipe 
technologies to meet or exceed regulatory requirements and to reduce 
the costs of waste management.
    The organizations and individuals involved in the development of 
the Waste Minimization National Plan strongly urged EPA to promote 
source reduction and recycling over waste treatment and disposal to 
reduce or eliminate the potential long term effects of RCRA PBT 
chemicals which may build up in the environment. They recognized that, 
even with stringent waste management standards, waste management units 
may fail, accidents may occur during transport and handling, and de 
minimis authorized releases may, nevertheless, occur. As a result, 
although many sources of these chemicals may individually be in 
compliance with hazardous waste and other regulations, RCRA PBT 
chemicals may continue to be released and build up in the environment. 
Reducing RCRA PBT chemical generation at the source is a more certain 
way of reducing or eliminating potential RCRA PBT risks to the 
environment, while reducing or eliminating the costs of managing 
wastes.

H. How Will EPA Work With States, Industries, and Other Interested 
Parties Who Have Different Priorities?

    EPA encourages Federal government agencies, States, the regulated 
community and other organizations to incorporate the priorities 
contained in today's proposed RCRA PBT list in their current 
environmental priorities and programs. EPA is aware that some 
organizations have chemical reduction priorities which differ in 
varying degrees from today's List. Examples of chemical priority lists 
from 15 State, tribal and international organizations are in the docket 
for today's notice. Based on a comparison of these lists with today's 
draft RCRA PBT List, EPA believes many organizations will find 
chemicals that are common to their own and today's List.
    EPA believes establishing common priorities provides an opportunity 
for progress toward the national RCRA PBT reduction goal. Therefore, 
EPA will actively work with States, industry, environmental groups and 
other interested parties to identify and integrate, to the extent 
possible, common RCRA PBT reduction priorities and multimedia 
implementation approaches to promote progress toward the national RCRA 
PBT chemical reduction goals.
    EPA believes States should use flexibility available through the 
National Environmental Performance Partnership System (NEPPS) to 
address priorities for multi-media, multi-programmatic environmental 
protection, including the priorities contained in today's List. EPA has 
included a goal, similar to the WMNP goal, as a Core Performance 
Measure in the NEPPS program. This goal seeks to ``decrease the 
quantity of waste generated, decrease the toxicity of waste generated, 
and increase recycling of wastes.

II. Waste Minimization Prioritization Tool Revisions and 
Information Stewardship

A. What is the Waste Minimization Prioritization Tool? When and How Was 
it Revised?

    The Waste Minimization Prioritization Tool (WMPT), a Windows-based 
chemical hazard screening tool developed by EPA, generates relative 
rankings of chemicals based on their potential to cause chronic human 
health and ecological problems. The WMPT generates rankings based on 
four sets of chemical properties, including: Chemical persistence, 
bioaccumulation potential, chronic human and ecological toxicity, and 
chemical mass. The last property,

[[Page 60336]]

chemical mass, is an optional variable that can be used at the user's 
discretion to generate rankings.
    This section outlines the process EPA used to seek public review of 
the WMPT, an outline of comments received, and a summary of the changes 
made to the WMPT in response to the comments. EPA used WMPT rankings 
based on the first three of the four properties noted above as input to 
the development of the RCRA PBT List. The reasons for this are 
described in the following sections.
    EPA released Beta Version 1.0 of the WMPT software \4\ and the 
accompanying User's Guide \5\ for public comment on June 23, 1997.\6\ 
In addition to the public comments received in the docket, EPA received 
comments from several other sources during the public comment period, 
including: peer review comments obtained from technical experts in 
industry, environmental groups, and states during a focus group meeting 
in September 1997; comments from an intra-Agency technical workgroup 
that reviewed the WMPT as a means of identifying ``PBT'' chemicals; and 
comments from a WMPT pilot project conducted by EPA Region 9 in the 
Santa Clara Valley, California. Comments were received on many facets 
of the WMPT. EPA received a variety of comments, including 
recommendations to:
---------------------------------------------------------------------------

    \4\ EPA530-C-97-003.
    \5\ Waste Minimization Prioritization Tool (Beta Test Version 
1.0): User's Guide and System Documentation (EPA530-R-97-019).
    \6\ 62 FR 33868.
---------------------------------------------------------------------------

     Modify the weighting and aggregation of persistence, 
bioaccumulation, human toxicity, and ecological toxicity scores in the 
WMPT.
     Modify the WMPT to better represent actual risk, as 
opposed to hazard.
     Revise the data quality hierarchies for persistence and 
bioaccumulation data to place preference on measured data (e.g., data 
gathered in laboratory tests and field studies) rather than predicted 
data (i.e., data derived from predictive models).
     Improve the quality of data that are used as the basis for 
scoring by updating existing Agency data sources (e.g., the Integrated 
Risk Information System) and by incorporating new sources of data 
currently available to EPA or obtainable from non-EPA sources.
     Provide the rationale behind the ``fenceline values'' 
(i.e., thresholds) that separate low, medium, and high scores.
     Score metals based on bioavailability rather than 
environmental persistence.
     Modify the persistence scoring approach to consider 
partitioning to media other than water (e.g., to air).
     Modify the current low/medium/high ``binning'' approach to 
include more than three bins and better discriminate among chemicals in 
scoring.
     Provide a better indication of the uncertainty associated 
with chemical values and scores by providing additional information on 
the sources of data used in the WMPT and on the quality of the data.
     Complete a peer review of the WMPT.
     Provide a process for modifying data values and scores in 
the WMPT as new data become available.
    An intra-Agency WMPT Workgroup was established to review the 
comments and provide recommendations on changes to the WMPT. With the 
purpose in mind of preparing chemical rankings for development of the 
RCRA PBT List, the Workgroup focused on addressing technical and 
scientific comments that would potentially affect RCRA PBT chemical 
scores. Comments that would not affect RCRA PBT chemical scores (e.g., 
comments recommending improving the user-friendliness of the Tool and 
User's Guide) were deferred until a later time.
    EPA considered the comments and recommendations. As a result, the 
following changes were made to the WMPT:
     For each chemical, the higher of the human health and 
ecological concern scores (previously referred to as human health and 
ecological risk potential scores) was used to indicate overall concern 
for the purpose of developing the RCRA PBT List, rather than adding the 
two scores together.
     Measured data were given preference over predicted data in 
deriving persistence and bioaccumulation scores. Adjustments in data 
preferences were made in scoring bioaccumulation potential, (i.e., 
bioaccumulation factors were given preference over bioconcentration 
factors, and the log of the octanol-water partition coefficient was no 
longer used).
     New persistence, bioaccumulation, human toxicity, and 
ecological toxicity data (which meet our data quality standards) from a 
number of sources were included in the WMPT.
     The fenceline values separating low, medium, and high 
scores for persistence, bioaccumulation, and toxicity were better 
documented; in some cases, the fenceline values were recalculated.
     A multimedia partitioning model was used to estimate the 
partitioning of chemicals to air, water, soils, and sediments and to 
calculate overall environmental persistence, rather than estimating 
persistence in surface water alone.
     Data transparency was improved by better documenting data 
sources and indicating the preference levels for the underlying data 
used for scoring; some data that could not be sufficiently documented 
for the purpose of the WMPT were removed.
    The comments received and EPA's responses are discussed in detail 
in the Waste Minimization Prioritization Tool Comment Response Document 
for the RCRA Waste Minimization PBT Chemical List Docket (referred to 
as the WMPT Comment Response Document below). This document is 
available in RCRA docket #F-98-MMLP-FFFFF and at EPA's Internet home 
page at www.epa.gov/wastemin.
    After making the changes to the WMPT outlined above, EPA prepared 
spreadsheets containing revised data and scoring information. This 
information was used as input for developing the RCRA PBT List. As a 
result of the expanded and improved data used in the WMPT, 
approximately 2,900 chemicals receive human health or ecological 
concern scores, compared with approximately 1,800 chemicals in the beta 
version of the WMPT. Of the 2,900 chemicals, 122 chemicals score from 7 
to 9 (i.e., relatively high) for human health concern and 666 score 
from 7 to 9 for ecological concern. Some score from 7 to 9 for both 
criteria. Altogether, 681 chemicals score from 7 to 9 for one or both 
of the two scores.
    EPA has placed in the docket (F-98-MMLP-FFFFF) 
a document titled Waste Minimization Prioritization Tool Spreadsheet 
Document for the RCRA Waste Minimization PBT Chemical List Docket 
(referred to below as the WMPT Spreadsheet Document) that: (1) explains 
changes made to the WMPT as a result of the public and peer review 
processes, and (2) displays spreadsheets and scoring information for 
1,300 chemicals which received a score of 6 or above for human health 
or ecological concern. This document is also available at EPA's 
Internet home page at www.epa.gov/wastemin.
    Information on the approximately 3,900 chemicals that scored from 3 
to 5 or that are unscored is not included in the docket, since these 
chemicals did not appear to be appropriate candidates for the RCRA PBT 
List. Information on these chemicals will be provided in a future 
version of the WMPT.

[[Page 60337]]

    The WMPT Comment Response Document and WMPT Spreadsheet Document 
are included in today's docket to provide the reader with background 
information on changes made to the WMPT and its use as a foundation for 
the development of today's draft RCRA PBT List. The WMPT spreadsheets 
contained in the docket are not intended to support other applications 
at this time. EPA is not requesting public comment on this information, 
since the WMPT has already received widespread and comprehensive public 
review. Additional applications beyond supporting the development of 
today's draft RCRA PBT List will be discussed when the WMPT is re-
released in 1999. That release of the WMPT revisions will include the 
scoring changes used in today's notice and improvements to the tool's 
software features.

B. How Will Ensure Stewardship of the Waste Minimization Prioritization 
Tool and Underlying Scientific Information?

    EPA is committed to coordinating the collection of environmental 
data and to making it available to the public through the Agency's 
``Reinventing Environmental Information Initiative.'' In 1997,\7\ EPA 
announced three important information management reforms, which:
---------------------------------------------------------------------------

    \7\ Administrator Carol Browner and Deputy Administrator Fred 
Hansen. EPA Common Sense Initiative Meeting. July 21, 1997.
---------------------------------------------------------------------------

     Establish key data standards to improve the value of 
environmental information, data sharing and integration;
     Provide universal voluntary access to electronic reporting 
to reduce burdens and improve data quality and timeliness; and
     Implement these data standards and electronic reporting 
reforms in the Agency's national systems in partnership with the states 
through the One Stop Program.
    Consistent with these principles, EPA commits to maintaining sound 
scientific information as a foundation for reducing RCRA PBT 
generation. The EPA has taken measures to practice principles of 
information stewardship in the development of today's draft RCRA PBT 
List by:
     Identifying the most up to date and documented information 
that is readily available;
     Excluding undocumented scientific information;
     Seeking expert advice to make assumptions, assess data 
quality and weigh contradictory information;
     Making information about data sources, data quality, 
assumptions publicly known;
     Inviting public review and comment on the data used; and
     Making appropriate adjustments to information.
    The Office of Solid Waste intends to follow these principles of 
information stewardship to ensure the integrity of data used in the 
Waste Minimization Prioritization Tool. As noted above, EPA will 
release an updated, user-friendly version of the WMPT in 1999, and will 
discuss how best to maintain stewardship of this tool and the 
underlying data with interested organizations and individuals at that 
time.

III. Development of Today's Draft RCRA PBT List

    The Agency followed several steps to develop today's draft RCRA 
Waste Minimization PBT Chemical List (referred to as the RCRA PBT List 
below). Each of these steps is discussed in more detail below.

A. How Were Initial Candidates for the RCRA PBT List Identified?

    The first step in developing today's draft RCRA PBT List was to 
assemble an initial list of candidate chemicals for further 
examination. EPA drew from two sources to establish this initial 
candidate chemical list: (1) The Waste Minimization Prioritization Tool 
discussed above, and (2) a composite list of PBT chemicals identified 
as priorities by other EPA program offices. This step is discussed 
below, and is described in the Chemical Screening Report for the RCRA 
PBT List Docket (referred to below as the Screening Report), which is 
located in RCRA docket number F-98-MMLP-FFFFF.
1. Candidates From the Waste Minimization Prioritization Tool
    EPA selected as candidates from the WMPT those chemicals which 
scored 7 or higher (on a scale of 3-9) for either human health concern 
or ecological concern. A total of 681 chemicals scored in the WMPT met 
this criterion. EPA then grouped certain polycyclic aromatic 
hydrocarbons into a single polycyclic aromatic hydrocarbons category, 
and grouped individually listed polychlorinated biphenyls with the 
existing polychlorinated biphenyls category, resulting in a total of 
660 candidate chemicals and chemical groups.
    EPA selected the cut-off score of 7 for human health or ecological 
concern in order to ensure that chemical candidates represent at least 
moderately high concern for PBT. In order to attain a score of 7, a 
chemical must receive the highest WMPT score for at least two of the 
three factors (P, B and T) or the highest score for one factor and 
moderate scores for the other two factors. EPA believes that a higher 
cut-off score would be overly restrictive, eliminating from further 
consideration many chemicals of significant RCRA PBT concern, while a 
lower cut-off score would be unnecessarily expansive, drawing in many 
chemicals which would not represent a sufficiently high level of RCRA 
PBT concern for this national PBT waste minimization effort.
2. PBT Priorities Identified by Other EPA Programs
    In addition to drawing candidate chemicals from the WMPT, EPA 
considered PBT chemical priorities identified by other EPA programs 
through internal PBT coordination efforts. This list of 34 chemicals 
included 18 chemicals which scored below 7 for human health or 
ecological concern in the WMPT, and 16 chemicals that were either not 
included in the WMPT, or were included, but were not scored because 
there were insufficient data. These chemicals were included in the 
candidate pool for development of the RCRA PBT List to determine the 
extent to which they may also be a RCRA PBT waste minimization 
candidate. Including these 34 chemicals in the candidate pool brought 
the total number of candidate chemicals and chemical groups to 694.

B. What Inclusion/Elimination Criteria Were First Applied to the 
Candidate Chemicals?

    After assembling the initial candidate chemical list, EPA 
eliminated chemicals that would not be good candidates for RCRA waste 
minimization efforts because they are unlikely to be present in RCRA 
hazardous waste in significant quantities, or are present, but are not 
highly toxic. Three criteria were used to screen out these chemicals: 
pesticides which are banned from production and use; chemicals with 
zero reported quantities in waste; and chemicals with low WMPT toxicity 
scores. This step is summarized below, and is described in detail in 
the Screening Report.
1. Banned Pesticides
    EPA first eliminated those chemicals that are pesticides banned 
from use in the United States and are not known to have other, non-
pesticidal sources or uses. This screen eliminated 28 chemicals from 
further consideration, including a number of well-known PBT chemical 
priorities such as DDT. EPA

[[Page 60338]]

did not eliminate from further consideration pesticides that are 
``severely restricted,'' but not banned in the U.S.
2. Chemicals Not Present in RCRA Wastes
    EPA also eliminated from further consideration chemicals that are 
not likely to be found in RCRA hazardous waste, based on quantities 
reported in the Agency's Toxics Release Inventory (TRI) database \8\ 
and the National Hazardous Waste Constituent Survey (NHWCS).\9\ 
Chemical quantities reported in the TRI were adjusted to estimate 
quantities present in hazardous waste streams by: including only TRI 
reporters who had RCRA ID numbers; in the case of underground injected 
wastes, including only TRI reporters with RCRA ID numbers who also had 
RCRA UIC (Underground Injection [well] Code) ID numbers; and excluding 
air and water releases from TRI production-related wastes. This screen 
eliminated 510 candidate chemicals, leaving 156 chemicals to be 
considered further in developing the RCRA waste minimization list. Some 
highly PBT chemicals were eliminated in this step (e.g., dioxin) 
because they are generated in very small quantities, which are not 
reported in the TRI. These were flagged and re-examined in the last 
step, described below in Section E.
---------------------------------------------------------------------------

    \8\ U.S. EPA. 1997. 1991 and 1995 Toxic Release Inventory (TRI) 
Data.
    \9\ U.S. EPA. 1998. National Hazardous Waste Constituent Survey. 
Office of Solid Waste. Washington, DC. This is a survey of chemical 
constituent presence in hazardous waste streams managed by RCRA 
treatment, storage and disposal facilities.
---------------------------------------------------------------------------

3. Chemicals With Low Toxicity
    Finally, EPA checked to ensure that none of the 156 chemicals 
passing the above screens became a candidate based on high P and/or B 
scores, but had a low score for human health or ecological toxicity. 
The rationale for this screen was that, even though some chemicals may 
persist or bioaccumulate in the environment, they should not be a 
candidate for the national RCRA PBT List if the chemical is not likely 
to be at least moderately toxic in the environment. None of the 156 
candidate chemicals had low toxicity scores.

C. How Were the Remaining Candidate Chemicals Ranked?

    To identify the best candidate chemicals for RCRA source reduction 
and recycling efforts, EPA developed four ``primary'' criteria for 
ranking the remaining chemicals. These criteria included: (1) Each 
chemical's PBT score from the WMPT; (2) chemical quantity and 
prevalence (or frequency of occurrence) in hazardous waste; (3) 
evidence that the chemical is present in the environment, particularly 
at levels of concern; and (4) the degree to which the chemical is a 
concern to the RCRA program.
    Ranking the candidate chemicals was completed by: Summing 
subcriteria scores within each of the four primary criteria discussed 
above; converting the scores for each primary criterion to a 25 point 
scale (i.e., the Agency gave equal weight to the four primary 
criteria); summing scores for each chemical; and arranging the 
chemicals in rank order on a scale of 1-100. The individual subcriteria 
were scored on a 0, 1, 2, 3 scale (except where noted). The values on 
this scale were assigned to different ranges of data values by 
examining the underlying data distributions and using natural breaks in 
the distributions or creating comparably sized groups. The process used 
to score and rank chemicals in this step is summarized below and is 
described in detail in the Chemical Ranking Report for the RCRA PBT 
List Docket (referred to below as the Ranking Report), located in RCRA 
docket number F-98-MMLP-FFFFF.
1. PBT Scores
    In this step, each candidate chemical was scored based on the 
higher of its WMPT human or ecological concern scores. The scoring 
approach is provided in Table 1 below. Each chemical with a WMPT score 
was assigned a subcriterion score from 0-3. Chemicals not scored in the 
WMPT were ranked by summing and normalizing scores for the remaining 
three primary criteria, to compensate for the missing WMPT score.

                  Table 1.--PBT Characteristics Scoring
------------------------------------------------------------------------
                                                                  Sub-
               PBT characteristics subcriterion                criterion
                                                                 score
------------------------------------------------------------------------
Higher of WMPT human health and ecological concern scores
 equals 9....................................................         3
Higher of WMPT human health and ecological concern scores
 equals 8....................................................         2
Higher of WMPT human health and ecological concern scores
 equals 7....................................................         1
WMPT human health and ecological concern scores are both less
 than 7......................................................         0
------------------------------------------------------------------------

2. Quantity and Prevalence
    The Agency believes that RCRA PBT chemicals which occur in greater 
quantities, or are more prevalent, in hazardous waste should be given a 
higher national priority for RCRA waste minimization than other PBT 
chemicals. Therefore, EPA assigned higher scores to chemicals with 
greater quantity, or prevalence, in hazardous waste.
    EPA used TRI and NHWCS data to determine chemical quantities in 
waste and used Biennial Reporting System (BRS) data 10 to 
determine waste stream quantities associated with each chemical. EPA 
also used TRI, NHWCS, and BRS data to determine the number of 
facilities generating or managing each chemical in hazardous waste.
---------------------------------------------------------------------------

    \10\ U.S. EPA. 1997. Biennial Reporting System Flat Files. 
Office of Solid Waste and Emergency Response, Washington, DC.
---------------------------------------------------------------------------

    TRI quantity and prevalence data were adjusted to identify and 
estimate chemical quantities and prevalence in RCRA hazardous waste by: 
(1) Including only TRI reporters who had RCRA ID numbers; (2) in the 
case of underground injected wastes, including only TRI reporters with 
RCRA ID numbers who also had RCRA UIC ID numbers; and (3) excluding air 
and water releases from TRI production-related waste. NHWCS quantity 
and prevalence data were used only where TRI quantity and prevalence 
data were unavailable. To estimate the quantities of BRS waste streams 
and number of generators associated with particular chemicals, EPA used 
the RCRA Chemical-Waste Code Crosswalk,11 which identifies 
hazardous waste codes that may be associated with particular chemicals.
---------------------------------------------------------------------------

    \11\ The RCRA Chemical-Waste Code Crosswalk (EPA530-D-97-005) is 
from the beta version of the WMPT; it is included in RCRA Docket #F-
98-MMLP-FFFFF. Chemicals not listed in the crosswalk were not 
evaluated on the BRS-based criteria.
---------------------------------------------------------------------------

    The TRI reports quantity information on both metals and metal 
compounds. The quantity information reported for a metal compound only 
includes the metal component of the compound. In keeping with this 
approach for metal reporting, EPA added together the quantities 
reported in TRI as metals and metal compounds.
    The TRI/NHWCS score and the BRS score were weighted equally (i.e., 
were added together and divided by two) in deriving both the quantity 
and prevalence subcriteria scores. If the BRS score was missing for a 
chemical, the TRI/NHWCS score was used as the quantity or prevalence 
subscriterion score. The quantity subcriterion score was added to the 
prevalence subcriterion score in deriving the

[[Page 60339]]

quantity/prevalence criterion score for each chemical. The scoring for 
quantity and prevalence is presented in Table 2 below.

                Table 2.--Quantity and Prevalence Scoring
------------------------------------------------------------------------
                                                            Subcriterion
Quantity/prevalence subcriterion         Value range            score
------------------------------------------------------------------------
TRI chemical quantity (pounds/    Greater than 10,000,000.             3
 yr).
                                  1,000,000-10,000,000....             2
                                  1-1,000,000.............             1
                                  Less than 1.............             0
NHWCS chemical quantity (pounds/  Greater than 1,000,000..             3
 yr).
                                  100,000-1,000,000.......             2
                                  1-100,000...............             1
                                  Less than 1.............             0
BRS waste stream quantity (tons/  Greater than 100,000,000             3
 yr).
                                  10,000,000-100,000,000..             2
                                  1-10,000,000............             1
                                  Less than 1.............             0
TRI number of generators........  More than 99............             3
                                  10-99...................             2
                                  1-9.....................             1
                                  0.......................             0
NHWCS number of handlers \12\...  More than 10............             3
                                  5-10....................             2
                                  1-4.....................             1
                                  0.......................             0
BRS number of generators........  More than 9,999.........             3
                                  1,000-9,999.............             2
                                  1-999...................             1
                                  0.......................             0
------------------------------------------------------------------------

3. Environmental Presence12
    The Agency believes that PBT chemicals which are detected in the 
environment more frequently than other chemicals should be given higher 
priority for reduction through source reduction and recycling. EPA 
ranked each chemical's ``presence in the environment'' using 
measurement indicators contained in the following three national 
databases: (1) EPA's Fish Advisory Database 13 (EPA used the 
most current year of fish advisory data in the U.S.--1997); (2) EPA's 
National Sediment Inventory 14 (EPA used data on sediment 
contamination in the U.S. for all years contained in the database; and 
(3) the Agency for Toxic Substances and Disease Registry's Hazdat 
Database 15 (EPA used data on chemicals found in the toxic 
cleanup sites identified on the EPA's Superfund National Priority List 
(NPL) covered under the Comprehensive Environmental Response, 
Compensation and Liability Act.
---------------------------------------------------------------------------

    \12\ The number of handlers is the number of RCRA treatment, 
storage, or disposal facilities that managed a chemical, rather than 
the number of generators of the chemical.
    \13\ U.S. EPA. 1998. 1997 National Listing of Fish Consumption 
Advisories. Office of Water, Washington, DC. www.epa.gov/OST/
fishadvice. June.
    \14\ U.S. EPA. 1997. The Incidence and Severity of Sediment 
Contamination in Surface Waters of the United States; Volume 1: The 
National Sediment Quality Survey. Office of Science and Technology, 
Washington, DC. EPA/823/R-97/006.
    \15\ Agency for Toxic Substances and Disease Registry. 1998. 
Hazardous Substance Release/Health Effects Database. website:
    atsdr1.atsdr.cdc.gov/8080/hazdat/html.
    EPA used the ATSDR data since no comparable data were readily 
available from RCRA corrective action sites.
---------------------------------------------------------------------------

    Scores were developed using the scoring approach in Table 3 below. 
Each environmental presence subcriterion was scored from 0-3. The 
scores for the three subcriteria were weighted equally (in this case 
being added together) in deriving an environmental presence criterion 
score for each PBT chemical.

                Table 3.--Environmental Presence Scoring
------------------------------------------------------------------------
     Environmental presence                                 Subcriterion
          subcriterion                   Value range            score
------------------------------------------------------------------------
Fish Advisory Database (1997      More than 99 advisories.             3
 data).
                                  10-99 advisories........             2
                                  1-9 advisories..........             1
                                  No advisories...........             0
National Sediment Inventory       More than 999 detections             3
 (1980-1993).
                                  100-999 detections......             2
                                  1-99 detections.........             1
                                  No detections...........             0
ATSDR HazDat Database (all NPL    More than 499 sites.....             3
 sites).
                                  100-499 sites...........             2
                                  1-99 sites..............             1
                                  No sites................             0
------------------------------------------------------------------------


[[Page 60340]]

4. RCRA Programmatic Concern
    EPA believes PBT chemicals that are of particular concern to the 
RCRA program should be given higher priority in developing today's 
draft RCRA PBT List than PBT chemicals identified in the WMPT or other 
programs that are not a particular concern to the RCRA program. To 
identify ``RCRA-relevant'' PBT chemicals, EPA selected the candidate 
PBT chemicals which are found on one or more regulatory lists used in 
the RCRA hazardous waste generation, management, and corrective action 
programs. The scoring scheme for these chemicals is provided in Table 4 
below.
    EPA used a wider subcriterion scoring range (0-4) for this 
criterion to reflect the broad range of RCRA programmatic concerns. 
This wider scoring range was then normalized (i.e., was converted to a 
25 point scale) so that the criterion was weighted equally with the 
other primary criteria.
    A score of 4 was assigned to PBT chemicals that: (1) Are capable of 
forming dense nonaqueous phase liquids (DNAPLs) that make groundwater 
cleanups particularly difficult; 16 (2) are identified as 
``difficult to treat'' chemicals under the Land Disposal Restrictions 
(LDR) program; 17 or (3) are targeted for co-regulation 
under RCRA and the Clean Air Act Section 112 in EPA's proposed maximum 
achievable control technology (MACT) combustion rule for hazardous 
waste incinerators, cement kilns or light weight aggregate kilns, or 
are currently regulated under the RCRA boilers and industrial furnaces 
(BIF) rule (since chemicals regulated under these rules could 
potentially be transferred to the air or soil media after 
combustion).18, 19
---------------------------------------------------------------------------

    \16\ See the following three references:
    Cohen, R.M., J.W. Mercer, and J. Matthews. 1993. DNAPL Site 
Evaluation. CRC Press, Boca Raton, FL.
    U.S. EPA. 1993. Evaluation of the Likelihood of DNAPL Presence 
at NPL Sites, National Results. Office of Solid Waste and Emergency 
Response, Washington, DC. EPA/540/R-93/073.
    U.S. EPA. 1991. Estimating Potential for Occurrence of DNAPL at 
Superfund Sites. Office of Solid Waste and Emergency Response, 
Environmental Research Laboratory, Washington, DC. EPA publication 
9355-4-07FS.
    \17\ Eby, E. 1998. Internal communication. Waste Treatment 
Branch, Office of Solid Waste, U.S. EPA. May.
    \18\ U.S EPA. 1991. Burning of Hazardous Waste in Boilers and 
Industrial Furnaces: Final Rule. 56 FR 7134. February 21.
    \19\ U.S. EPA. 1996. Revised Standards for Hazardous Waste 
Combustors: Proposed Rule. 61 FR 173858. April 19.
---------------------------------------------------------------------------

    Chemicals which are not on any of the regulatory lists discussed in 
the previous paragraph, but are on the Toxicity Characteristic (TC) 
list (40 CFR 261.24) or the Appendix VII list of chemicals, which is 
used as the basis for hazardous waste listings (40 CFR part 261), are 
assigned a score of 3. The Agency has historically taken regulatory 
actions in the RCRA program based on risk assessments and damage cases 
involving these chemicals.
    If a chemical was not on any of the lists noted above but is 
regulated under RCRA based on technological standards rather than risk-
based standards (i.e, chemicals covered by the Universal Treatment 
Standards (UTS) list (40 CFR 268.48), it was assigned a score of 2. If 
a chemical was not on any of the lists noted above, but was on the RCRA 
P list of acute hazardous waste (40 CFR 261.33), the U list of toxic 
waste (40 CFR 261.33), the Appendix VIII hazardous waste constituent 
list (40 CFR part 261), or the Appendix IX ground water monitoring list 
(40 CFR part 264), the chemical was assigned a score of 1. These 
chemicals are regulated under RCRA, but are of lesser concern. For 
instance, Appendix IX chemicals are used to set permit parameters. 
However, if they are not on the lists mentioned above, are of lesser 
concern. In addition, although P list chemicals are of concern due to 
their acute hazards, they are generated infrequently and usually in 
small quantities.
    Chemicals not found on any of the lists discussed above received a 
0 score. The scoring of subcriteria for RCRA Programmatic Concern is 
summarized in Table 4 below.

               Table 4.--RCRA Programmatic Concern Scoring
------------------------------------------------------------------------
                                                            Subcriterion
          RCRA programmatic concern subcriterion                score
------------------------------------------------------------------------
Chemicals contained on any of the following lists: (1)
 Chemicals that can form dense non-aqueous phase liquids;
 (2) chemicals identified as ``difficult to treat,'' or
 (3) chemicals regulated under the MACT rule for hazardous
 waste incinerators, cement kilns and light weight
 aggregate kilns, or the RCRA rule for boilers and
 industrial furnaces......................................           4
Presence on the toxicity characteristic list or the
 Appendix VII list of chemicals serving as the basis for
 hazardous waste listings.................................           3
Presence on the land disposal restrictions universal
 treatment standards list.................................           2
Presence on the RCRA P list of acute hazardous waste, the
 U list of toxic waste, the Appendix VIII hazardous waste
 constituent list, or the Appendix IX ground water
 monitoring list..........................................           1
Chemical not present on any of the above RCRA lists.......           0
------------------------------------------------------------------------


[[Page 60341]]

    The Agency conducted limited sensitivity testing of the ranking 
methodology by observing changes in the rankings in response to 
modifying the ranking criteria. Several scenarios were tested, 
including eliminating each of the primary criteria in turn and 
eliminating both the RCRA Relevance and Environmental Presence criteria 
together.
    In general, the methodology appeared to be fairly robust in its 
identification of the top ranking chemicals. Scenarios which 
alternatively dropped the RCRA Relevance, Quantity/Prevalence, and the 
PBT Score criteria each displaced roughly 10 chemicals from the top 50. 
Elimination of the Environmental Presence criterion had less of an 
impact on the rankings than dropping the other criteria. This indicates 
that, when one of the four criteria is removed from the ranking method, 
the remaining criteria and data support the ranking to a substantial 
degree.
    In a more drastic sensitivity scenario, dropping two of the 
criteria, RCRA Relevance and Environmental Presence, together 
substantially altered the rankings--30 chemicals in the top 50 were 
displaced, and several chemicals changed by more than 50 rank 
positions. These results are not surprising considering the substantial 
change to the scoring method (half of the criteria are removed). For 
further information, see the report Revised Chemical Ranking 
Methodology Testing Results in RCRA docket number F-98-MMLP-FFFFF.

D. What Cutoff Was Applied to the Ranked Chemicals to Obtain the Draft 
RCRA PBT List?

    After ranking the 150 candidate chemicals, EPA selected a cutoff 
value to identify the ``top tier'' of chemicals for tracking on a 
national level. EPA narrowed the candidate list to the 61 chemicals 
which had a score of 50 points (the half way point on the scoring 
scale) as a basis for inclusion in the draft RCRA PBT List proposed 
today. EPA determined that a national list of 50 to 60 chemicals was 
appropriate, given limited Agency, State, and private resources to 
reduce and measure these chemicals.

E. What Final Adjustments Were Made to the Draft RCRA PBT List?

    As a final step, EPA added and removed certain chemicals from the 
list for the particular reasons described below. Adding and removing 
chemicals reduced the draft RCRA PBT List from 61 to 53 chemicals.
1. U.S./Canada Binational Agreement Level 1 Chemicals
    EPA added dioxins, furans, and octachlorosytrene to the RCRA PBT 
List because of their high priority on the ``Level 1'' list of the 
U.S./Canada Binational Agreement.20 Four other Level 1 
chemicals were already among the top tier chemicals for the RCRA PBT 
List.21 Nine chemicals on the Level 1 list, including eight 
banned pesticides and alkyl lead, are excluded because they are either 
no longer produced (e.g., banned pesticides), or are found in very 
limited quantities in wastes from only a few production processes 
(e.g., alkyl lead).22 In either case, these chemicals are 
not very amenable to reductions through waste minimization. The 
Binational Agreement and the Level 1 list are available for review in 
RCRA docket number F-98-MMLP-FFFFF.
---------------------------------------------------------------------------

    \20\ U.S. EPA. 1997. Great Lakes Binational Toxics Strategy. 
Great Lakes National Program Office, Chicago, IL. www.epa.gov/
grtlakes/p2/bnsintro.html
    \21\ These four chemicals include hexachlorobenzene, mercury and 
compounds, PCBs, and benzo(a)pyrene. PCBs were subsequently removed 
from the proposed RCRA PBT List (see discussion below), and 
benzo(a)pyrene was included in the category polycyclic aromatic 
hydrocarbons.
    \22\ The eight banned pesticides include aldrin, dieldrin, 
chlordane, DDT, DDD, DDE, toxaphene, and mirex.
---------------------------------------------------------------------------

2. Chemicals With Low or no PBT Scores
    The Agency initially added chemicals identified by other EPA 
programs to the candidate list to provide a comprehensive starting 
point in the RCRA PBT List development process. At this final step in 
the RCRA PBT List development process, six chemicals were removed for 
the following reasons. Five of the chemicals--tetrachlorethylene, 
trichlorethylene, methylene chloride, 1,2-dichloroethane, and 1,1,2,2-
tetrachloroethane--were removed because their WMPT PBT scores are below 
7. Although individual States may wish to pursue reductions in these 
chemicals, EPA determined they are not among the most highly toxic for 
a national list. The sixth, silver, was removed because it has no PBT 
score.
3. PCBs
    The Agency removed the PCB chemical group from the RCRA PBT List 
because production of PCBs is banned in the U.S. and waste minimization 
opportunities for PCBs in process waste streams are believed to be very 
limited.
4. Di-n-octyl Phthalate and Butyl Benzyl Phthalate
    The Agency previously removed both of these chemicals from the 
EPCRA Section 313 List of Toxic Chemicals in response to delisting 
petitions. Consequently, the Agency examined these chemicals more 
closely to determine whether to continue to include them on the draft 
RCRA PBT List. The Agency decided to remove di-n-octyl phthalate from 
the draft RCRA PBT List because data developed in response to that 
delisting petition indicated that the human and ecological toxicity 
data were not conclusive. However, EPA has retained butyl benzyl 
phthalate on the draft RCRA PBT List because the ecological toxicity 
criteria considered for delisting from the EPCRA list were different 
than the criteria used in the WMPT for determining high levels of 
concern for ecological toxicity.
5. Hexachlorocyclohexane Isomers
    The Agency removed the alpha, beta, and delta hexachlorocyclohexane 
isomers and retained the gamma isomer. The gamma isomer is believed to 
be the predominant PBT isomer in waste streams, and achieving waste 
minimization for this isomer would result in reductions in the other 
isomers as well.

IV. EPA's Draft RCRA Waste Minimization PBT Chemical List and 
Issues for Public Comment

A. Which Chemicals Are Included on the Draft RCRA PBT List?

    Table 5 below presents EPA's draft RCRA PBT List. The chemicals are 
listed in alphabetical order. No rank ordering is intended in this 
List, and, in fact, the List treats these chemicals as equal 
environmental priorities. The Chemical Abstract Service Registry Number 
(CASRN) is also shown, where available.

                      Table 5.--Draft RCRA PBT List
------------------------------------------------------------------------
                                                               CASRN
------------------------------------------------------------------------
Dioxins and Furans:

[[Page 60342]]

    Dioxins (PCDD)......................................  ..............
    Furans (PCDF).......................................  ..............
Chlorinated Solvents:
    Chloroform..........................................         67-66-3
    1,1-Dichloroethane..................................         75-34-3
    1,1,1-Trichloroethane...............................         71-55-6
Chlorobenzenes:
    1,2-Dichlorobenzene.................................         95-50-1
    1,3-Dichlorobenzene.................................        541-73-1
    1,4-Dichlorobenzene.................................        106-46-7
    1,2,4-Trichlorobenzene..............................        120-82-1
    1,2,4,5-Tetrachlorobenzene..........................         95-94-3
    Pentachlorobenzene..................................        608-93-5
    Hexachlorobenzene...................................        118-74-1
Other Halogenated Organics:
    4-Bromophenyl phenyl ether..........................        101-55-3
    Hexachlorobutadiene.................................         87-68-3
    Octachlorostyrene...................................      29082-74-4
Pesticides
    alpha-Endosulfan....................................        959-98-8
    beta-Endosulfan.....................................      33213-65-9
    Heptachlor..........................................         76-44-8
    Heptachlor epoxide..................................       1024-57-3
    gamma-Hexachlorocyclohexane.........................         58-89-9
    Methoxychlor........................................         72-43-5
    Pentachloronitrobenzene.............................         82-68-8
    Pentachlorophenol...................................         87-86-5
    2,4,5-Trichlorophenol...............................         95-95-4
Organonitrogens:
    Nitrobenzene........................................         98-95-3
Nonhalogenated Phenolics:
    Phenol..............................................        108-95-2
    2,4,6-tris-(1,1-Dimethylethyl)phenol................        732-26-3
Phthalate esters:
    Bis-(2-ethylhexyl) phthalate........................        117-81-7
    Butylbenzyl phthalate...............................         85-68-7
    Dibutyl phthalate...................................         84-74-2
Polycyclic aromatic hydrocarbons**:
    Acenaphthene........................................         83-32-9
    Acenapthylene.......................................        208-96-8
    Anthracene..........................................        120-12-7
    Benzo(g,h,l)perylene................................        191-24-2
    Fluoranthene........................................        206-44-0
    Fluorene............................................         86-73-7
    2-Methylnaphthalene.................................         91-57-6
    Naphthalene.........................................         91-20-3
    PAH group (as defined in TRI).......................
    Phenanthrene........................................         85-01-8
    Pyrene..............................................        129-00-0
Metals
    Antimony............................................       7440-36-0
    Arsenic.............................................       7440-38-2
    Beryllium...........................................       7440-41-7
    Cadmium.............................................       7440-43-9
    Chromium............................................       7440-47-3
    Copper..............................................       7440-50-8
    Lead................................................       7439-92-1
    Mercury.............................................       7439-97-6
    Nickel..............................................       7440-02-0
    Selenium............................................       7782-49-2
    Zinc................................................       7440-66-6
     Cyanide............................................        57-12-5
------------------------------------------------------------------------
** The Toxics Release Inventory reports some polycyclic aromatic
  hydrocarbons (PAHs) as a group, and reports other PAHs individually.
  The 10 individual PAHs listed in this table are not included in the
  TRI PAH group. See the Screening Report for a list of PAHs included in
  the TRI PAH group.


[[Page 60343]]

B. What Issues is EPA Requesting Public Comment On?

    The Agency welcomes public comment on any aspect of the methodology 
used to develop the draft RCRA PBT List, including the data sources, 
ranking criteria and scoring schemes, the cutoff criteria, and the 
final adjustments to the List. The Agency also requests comment on the 
specific issues listed below. The Agency is not requesting comment on 
the data or methodology used to develop the WMPT, or the scoring 
results of the WMPT. The WMPT went through a thorough, comprehensive 
and constructive public review and comment process. EPA has 
incorporated its response to those comments in the underpinnings of 
today's notice and therefore does not believe comments regarding the 
WMPT are generally pertinent to this effort.
    Specific issues for comment include:
1. Banned Chemicals
    Is it appropriate to eliminate chemicals from consideration for the 
draft RCRA PBT List because they are no longer used in production or 
generated in hazardous waste, or are generated in very limited 
quantities from very few production processes, and therefore are not 
good candidates for future reductions through waste minimization? Is it 
appropriate to eliminate banned pesticides, PCBs, and alkyl lead for 
this reason, as the Agency has done in developing the List?
2. Waste Minimization Feasibility
    Should the agency eliminate from consideration PBT chemicals 
contained in hazardous waste for which there are few feasible waste 
minimization options available, or should the agency consider these as 
an incentive to encourage research and development of waste 
minimization methods for these chemicals?
3. ``Non-measurable'' Chemicals
    The draft RCRA PBT List includes 16 chemicals that were reported in 
the National Hazardous Waste Constituent Survey but are not reported in 
the Toxics Release Inventory, and therefore, cannot be easily tracked 
over time. Is it appropriate to include on the List chemicals for that 
TRI data, or other annual chemical-specific data, are not readily 
available for tracking national chemical reduction progress? Are there 
other reliable national sources of chemical reporting data that could 
be used to track generation and reductions of these chemicals?
4. Chemicals With Very High P, B, and/or T Values
    Should chemicals with very high data values for persistence, 
bioaccumulation potential, human toxicity, and/or ecological toxicity 
(e.g., with values at the top end of the data distributions) be 
considered for addition to the RCRA PBT List, even though TRI data are 
not available for tracking progress? How would progress be measured for 
these chemicals?
5. Chemicals With Low Reported Quantities
    Several chemicals on the RCRA PBT List are estimated in the 
National Hazardous Waste Constituent Survey to be generated in 
quantities of less than 100 pounds per year. The Agency did not use a 
specific quantity cutoff in developing the RCRA PBT List. Should a 
quantity cutoff be used? If so, what is the appropriate value for the 
cutoff? Should different cutoffs be used for chemicals which are the 
most toxic compared to others which are less toxic? If so, what should 
those cutoffs be?
6. Priorities Identified by Other Organizations.
    Should EPA add to the RCRA PBT List State or other organization's 
priority chemicals which do not already appear on the List? Among these 
chemicals, should those with low or no PBT scores (e.g., waste 
solvents), or those with low or no chemical quantities (e.g., some 
Level 1 U.S./Canada Binational Agreement chemicals) be included? A list 
of chemical priorities identified by several States is located in RCRA 
docket number F-98-MMLP-FFFFF.
7. Including Recycled Wastes in Determining Quantities of RCRA-Relevant 
Waste Associated with Chemicals
    In considering the quantity and prevalence of candidates for the 
RCRA PBT List (step C.4 above), the Agency included quantities that 
were recycled in its scoring procedure. Should recycled quantities be 
included when determining the quantities of chemicals associated with 
hazardous wastes in developing the RCRA PBT List, or should EPA measure 
chemicals only at the point of generation?

    Dated: October 30, 1998.
Elizabeth A. Cotsworth,
Acting Director, Office of Solid Waste.
[FR Doc. 98-29952 Filed 11-6-98; 8:45 am]
BILLING CODE 6560-50-P