Notice of Availability of Draft RCRA Waste Minimization PBT Chemical List

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.

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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 ''

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\1\ New Approach Needed to Manage the Resource Conservation and

Recovery Act; p. 57; United States General Accounting Office Report

to Congress; July 1988.

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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:

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

045.

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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).

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\3\ Minimization of Hazardous Waste Report to Congress, October

1986, EPA-530-SW-86-033.

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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:

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\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.

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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:

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\7\ Administrator Carol Browner and Deputy Administrator Fred

Hansen. EPA Common Sense Initiative Meeting. July 21, 1997.

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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