60194 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

III. What is the Agency Authority for

Taking This Action?

Section 6(f)(1) of FIFRA provides that

a registrant of a pesticide product may

at any time request that any of its

pesticide registrations be amended to

delete one or more uses. The Act further

provides that, before acting on the

request, EPA must publish a notice of

receipt of any such request in the

Federal Register. Thereafter, the

Administrator may approve such a

request.

IV. Procedures for Withdrawal of

Request

Registrants who choose to withdraw a

request for use deletion must submit

such withdrawal in writing to James A.

Hollins, at the address given above,

postmarked May 2, 2000.

V. Provisions for Disposition of Existing

Stocks

The Agency has authorized the

registrants to sell or distribute product

under the previously approved labeling

for a period of 18–months after approval

of the revision, unless other restrictions

have been imposed, as in special review

actions.

List of Subjects

Environmental protection,

Dated: October 4, 1999.

Richard D. Schmitt,

Acting Director, Information Resources &

Services Division.

[FR Doc. 99–28890 Filed 11–3–99; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–6458–9]

Sanders Aviation Superfund Site,

Proposed Notice of Administrative

Settlement

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice; request for public

comment.

SUMMARY: In accordance with section

122(i) of the Comprehensive

Environmental Response,

Compensation, and Liability Act, as

amended (‘‘CERCLA’’), 42 U.S.C.

9622(i), notice is hereby given of a

proposed administrative settlement for

recovery of past response costs

concerning the Sanders Aviation

Superfund Site in Tempe, Arizona with

the Alfred P. Sanders Trust (‘‘Trust’’)

and the trustees of the Trust. Pursuant

to the Agreement, the Trust will arrange

for the sale of the Trust property.

Seventy-five percent of the proceeds of

the sale will be paid to the Hazardous

Substance Superfund and twenty-five

percent will be paid to the Trust. This

allocation is a close approximation of

the costs each party has contributed to

cleaning up the site. The settlement

includes a covenant not to sue the

settling parties pursuant to Sections 106

and 107(a) of CERCLA, 42 U.S.C. 9606,

9607(a). For thirty (30) days following

the date of publication of this notice,

EPA will receive written comments

relating to the settlement. EPA will

consider all comments received and

may modify or withdraw its consent to

the settlement if comments received

disclose facts or considerations which

indicate that the settlement is

inappropriate, improper, or inadequate.

The United States’ response to any

comments received will be available for

public inspection at the U.S.

Environmental Protection Agency, 75

Hawthorne Street, San Francisco, CA

94105.

DATES: Comments must be submitted on

or before December 6, 1999.

ADDRESSES: Comments should reference

the Sanders Aviation Removal Site,

Tempe, Arizona and EPA Docket No.

99–06 and should be addressed to Kara

Christenson, Office of Regional Counsel,

U.S. Environmental Protection Agency,

75 Hawthorne Street, San Francisco, CA

94105.

AVAILABILITY: The proposed settlement is

available for public inspection at the

U.S. Environmental Protection Agency,

75 Hawthorne Street, San Francisco, CA

94105. A copy of the proposed

settlement may be obtained from Kara

Christenson, Office of Regional Counsel

U.S. Environmental Protection Agency,

75 Hawthorne Street, San Francisco, CA

94105; and at the Tempe Public Library,

3500 South Rural Road, Tempe,

Arizona.

FOR FURTHER INFORMATION CONTACT: Kara

Christenson, Office of Regional Counsel

U.S. Environmental Protection Agency,

75 Hawthorne Street, San Francisco, CA

94105, telephone: (415) 744–1330.

Dated: October 25, 1999.

Michael Feeley,

Deputy Director, Superfund Division, Region

IX.

[FR Doc. 99–28885 Filed 11–3–99; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

[OPPTS–53171A; FRL–6097–7]

Category for Persistent,

Bioaccumulative, and Toxic New

Chemical Substances

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Policy statement.

SUMMARY: EPA groups new chemical

substances with similar structural and

toxicological properties into categories

to facilitate premanufacture assessment

and regulation. These groupings enable

both Toxic Substances Control Act

(TSCA) section 5(a)(1) Premanufacture

Notice (PMN) submitters and EPA

reviewers to benefit from accumulated

data and decisional precedents and have

streamlined the process for Agency

review of and regulatory follow-up on

new chemical substances. Consistent

with TSCA section 26(c), which allows

EPA action under TSCA with respect to

categories of chemical substances or

mixtures, EPA is issuing this policy

statement regarding a category of

persistent, bioaccumulative, and toxic

(PBT) new chemical substances.

DATES: This document will become

effective January 3, 2000.

FOR FURTHER INFORMATION CONTACT: For

general information contact: Christine

Augustyniak, Associate Director,

Environmental Assistance Division

(7408), Office of Pollution Prevention

and Toxics, Environmental Protection

Agency, 401 M St., SW., Washington,

DC 20460; telephone numbers: 202–

554–1404 and TDD: 202–554–0551; email address: TSCA-Hotline@epa.gov.

For technical information contact:

Kenneth Moss, Chemical Control

Division (7405), Environmental

Protection Agency, 401 M St., SW.,

Washington, DC 20460; telephone

number: 202–260–3395; fax number:

202–260–0118; e-mail address:

moss.kenneth@epa.gov.

SUPPLEMENTARY INFORMATION: On

October 5, 1998 (63 FR 53417) (FRL–

5571–6), EPA published a Federal

Register notice soliciting comments on

proposed criteria for identifying PBT

chemical substances and their

supporting scientific rationale. This

policy statement responds to comments

on the proposed criteria for identifying

PBT new chemical substances and their

supporting scientific rationale. Please

consult the October 5, 1998 (63 FR

53417) Federal Register notice for

further information on the TSCA new

chemicals program. The docket control
Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices 60195

number for this document is OPPTS–

53171A.

I. General Information

A. Does This Document Apply to Me?

You may be potentially affected by

this document if you are or may in the

future be a submitter of a PMN under

TSCA. Potentially affected entities may

include, but are not limited to the

following:

Category NAICS Code SIC Codes Examples of Potentially Affected Entities

Chemical manufacturers or importers 325, 32411 28, 2911 Anyone who plans to manufacture or import a

new chemical substance (as defined in TSCA

Section 3) for a non-exempt commercial purpose is required to provide the EPA with a

PMN at least 90 days prior to the activity. Any

TSCA chemical substance that is not on the

TSCA Inventory is classified as a new chemical. New chemical substances submitted by

chemical manufacturers or importers as PMNs

and which are determined by EPA to meet the

PBT criteria described here may be subject to

regulatory controls under TSCA section 5(e).

This listing is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this document. Other types

of entities not listed above could also be

affected. The four-digit Standard

Industrial Classification (SIC) codes or

the six-digit North American Industrial

Classification System (NAICS) codes

have been provided to assist you and

others in determining whether or not

this document might apply to certain

entities. To determine whether you or

your business is affected by this

document, you should carefully

examine the applicability provisions in

40 CFR 720.22. If you have any

questions regarding the applicability of

this document to a particular entity,

consult the technical person listed in

the ‘‘FOR FURTHER INFORMATION

CONTACT’’ section.

B. How Can I Get Additional

Information, Including Copies of This

Document and Other Related

Documents?

1. Electronically. You may obtain

copies of this document from the EPA

Internet Home Page at http://

www.epa.gov/. On the Home Page select

‘‘Laws and Regulations’’ and then look

up the entry for this document under

the ‘‘Federal Register - Environmental

Documents.’’ You can also go directly to

the ‘‘Federal Register’’ listings at http:/

/www.epa.gov/fedrgstr/. To access

information about the TSCA New

Chemicals Program, go directly to the

Home Page for the New Chemicals

Program, within the Office of Pollution

Prevention and Toxics, at http://

www.epa.gov/opptintr/newchms/.

2. In person. The Agency has

established an official record for this

document under docket control number

OPPTS–53171A. The official record

consists of the documents specifically

referenced in this document, any public

comments received during an applicable

comment period, and other information

related to this document, including any

information claimed as Confidential

Business Information (CBI). This official

record includes the documents that are

physically located in the docket, as well

as the documents that are referenced in

those documents. The public version of

the official record does not include any

information claimed as CBI. The public

version of the official record, which

includes printed, paper versions of any

electronic comments submitted during

an applicable comment period, is

available for inspection in the TSCA

Nonconfidential Information Center,

Rm. NE B–607, Waterside Mall, 401 M

St., SW., Washington, DC. The Center is

open from 12 noon to 4 p.m., Monday

through Friday, excluding legal

holidays. The telephone number of the

Center is 202–260–7099.

3. By phone. If you need additional

information about this document, you

may also contact the person identified

in the ‘‘FOR FURTHER INFORMATION

CONTACT’’ section.

II. Background

A. Overview of the PMN Process

Under section 5(a) of TSCA, persons

must notify EPA at least 90 days before

manufacturing or importing a new

chemical substance for non-exempt

purposes. A new chemical substance, as

defined in section 3(9) of TSCA, is any

chemical substance (as defined by

section 3(2)) that is not included on the

Inventory compiled under section 8(b)

of TSCA.

Section 5 of TSCA gives EPA 90 days

to review a PMN (also referred to as a

‘‘section 5 notice’’). However, the

review period can be extended under

TSCA section 5(c) for good cause; it may

also be suspended voluntarily by the

mutual consent of EPA and the PMN

submitter. During the review period,

EPA may take action under TSCA

section 5(e) or (f) to prohibit or limit the

production, processing, distribution in

commerce, use, and disposal of new

chemical substances that raise health or

environmental concerns. If EPA has not

taken action under TSCA section 5(e) or

(f), the PMN submitter may manufacture

or import the new chemical substance

when the review period expires.

No later than 30 days after the PMN

submitter initiates manufacturing or

importing, it must provide EPA with a

notice of commencement of

manufacture or import. Section 8(b) of

TSCA provides that, upon receipt of

such a notice, EPA must add the

substance to the TSCA Inventory.

Thereafter, other manufacturers and

importers may engage in activities

involving the new substance without

submitting a PMN, unless the Agency

has used its Significant New Use Rule

(SNUR) authority under TSCA section

5(a)(2) to designate a use of a chemical

substance as a ‘‘significant new use.’’

Section 5(a)(1)(B) of TSCA would then

require persons to submit a Significant

New Use Notice (SNUN) to EPA at least

90 days before they manufacture,

import, or process the substance for the

use designated as significant. The

required SNUN provides EPA with the

opportunity to evaluate the intended

use, and if necessary, to prohibit or limit

that activity before it occurs.

B. History

Since 1979, EPA has reviewed over

30,000 TSCA section 5 submissions for

new chemical substances. During the

intervening years, EPA has

implemented various initiatives which

have enabled the Agency to review a

greater number of new chemicals more
60196 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

efficiently. In 1988, for example, EPA’s

Office of Toxic Substances (now the

Office of Pollution Prevention and

Toxics) first used its accumulated

experience to group chemical

substances with similar

physicochemical, structural, and

toxicological properties into working

categories (USEPA, 1988, see Unit

VI.8.). These categories, including the

subject one for PBT chemical

substances, are developed by EPA based

on available data and experience

reviewing PMNs on similar substances.

Such groupings enable both PMN

submitters and EPA reviewers to benefit

from the accumulated data and

decisional precedents and facilitates the

assessment of new chemical substances.

PBT chemical substances possess

characteristics of persistence (P) in the

environment, accumulation in

biological organisms (bioaccumulation

(B)), and toxicity (T) that make them

priority pollutants and potential risks to

humans and ecosystems. Prominent

examples of PBT chemical substances

include the insecticide DDT and

polychlorinated biphenyls (PCBs).

Establishment of a PBT category alerts

potential PMN submitters to possible

assessment or regulatory issues

associated with PBT new chemicals

review. It also provides a vehicle by

which the Agency may gauge the flow

of PBT chemical substances through the

TSCA New Chemicals Program and

measure the results of its risk screening

and risk management activities for PBT

new chemical substances; as such, it is

a major element in the Agency’s overall

strategy to further reduce risks from PBT

pollutants.

As described in the Federal Register

notice of October 5, 1998 (63 FR 53417),

development of the TSCA new PBT

chemicals policy has occurred in

coordination with U.S. national, U.S./

Canada binational, and international

efforts to identify and control the

environmental release of persistent

organic pollutants (POPs). The proposed

TSCA PBT category has been provided

to the Criteria Expert Group (CEG)

established at the first session of the

Intergovernmental Negotiating

Committee (INC) for an International

Legally Binding Instrument for

Implementing International Action on

Certain Persistent Organic Pollutants, in

accordance with the mandate given by

the Governing Council of the United

Nations Environment Programme

(UNEP) in paragraph 9 of its decision

19/13 C (http://irptc.unep.ch/pops/

gcpops¥e.html). The CEG is an openended technical working group with a

mandate to present to the INC proposals

for science-based criteria and a

procedure for identifying additional

POPs as candidates for future

international action. The CEG is to

incorporate criteria pertaining to

persistence, bioaccumulation, toxicity

and exposure in different global regions

and should take into account the

potential for regional and global

transport, including dispersion

mechanisms for the atmosphere and the

hydrosphere, migratory species, and the

need to reflect possible influences of

marine transport and tropical climates.

At its first meeting, October 26–30, 1998

in Bangkok, the CEG recommended that

the INC consider developing a provision

encouraging countries and regions to

include in their new chemicals schemes

elements relating to development and

introduction of new chemical POPs. The

U.S. described its proposed TSCA new

chemicals program policy for the

category of PBT new chemicals, and the

full text of the October 5, 1998 Federal

Register notice was distributed to all

delegations as a Conference Room

Paper. The CEG’s recommendation was

accepted at the second meeting of the

INC (January 25–29, 1999 in Nairobi)

and the INC will consider it further in

its deliberations.

This policy statement is important in

our new chemical assessment and TSCA

regulatory programs, and represents the

first formal statement of national policy

regarding new chemical ‘‘persistent

organic pollutants.’’ Under our domestic

program, the policy statement provides

guidance criteria for persistence,

bioaccumulation, and toxicity for new

chemicals and advises the industry

about our regulatory approach for

chemicals meeting the criteria.

Internationally, the Federal Register

notice of October 5, 1998 (63 FR 53417)

alerted the parties involved in

negotiation of the POPs Convention to

the need for inclusion of a new

chemicals provision in the Convention.

The issuance of the final policy

statement will reaffirm US leadership

on this issue and serve as a model for

other countries in taking steps to

discourage the introduction of POPs as

new chemicals and pesticides.

III. Discussion of Final Policy

Statement and Response to Comments

Today’s policy statement adopts the

criteria and testing strategy of the

Federal Register notice of October 5,

1998 (63 FR 53417), with minor

revisions. The Agency reviewed and

considered all comments received on

the October 5, 1998 (63 FR 53417)

notice. A complete copy of all

comments received is available in the

public docket for this document. A

discussion of the policy statement,

including a summary of significant

comments and the Agency’s response

follows:

A. Pigments

Comment 1-Pigments. Commenters

suggested that EPA not identify

pigments as bioaccumulators and were

concerned that testing could end up

being expensive for pigments, which are

persistent by design.

Response. EPA assesses PMN

chemical substances for PBT attributes

on a chemical-by-chemical basis,

regardless of whether or not they fall

into a chemical use category such as

pigments. Not all pigments are the same

and a precise definition of the term

‘‘pigment’’ is not available. As a result,

EPA does not have general ‘‘pigments’’

or ‘‘dyes’’ assessment categories; there

are, however, more specifically

described categories of dyes or pigments

that have been described by EPA (e.g.,

acid or amphoteric dyes,

dichlorobenzidine-based pigments, and

others; see categories document at http:/

/www.epa.gov/opptintr/newchms/

chemcat.htm). Moreover, the fact that a

substance is ‘‘persistent by design’’ by

itself is not a sufficient basis for

identifying a PBT new chemical

substance. Persistence is only one of

three criteria used to identify a chemical

as PBT. When combined with a

potential to bioaccumulate, toxicity

concern, and sufficient release to the

environment to result in potential risk

or significant exposure, pigments may

be of concern, whether or not they are

persistent by design. If a PMN chemical

is persistent by design, and becomes

subject to testing requirements by EPA,

it would be counterproductive to test

initially for persistence, but rather to

address the ‘‘B’’ and ‘‘T’’ criteria

instead.

B. Ready Biodegradability Testing

Comment 2-Ready biodegradability

testing. Commenters suggested that EPA

avoid the use of strict pass/fail criteria

for ready biodegradability of poorly

water-soluble substances.

Response. Poor water solubility does

not necessarily lead to inability to pass

a ready biodegradability test, as amply

demonstrated by the fact that many fats,

oil, petroleum hydrocarbons, etc. easily

pass ready biodegradability tests. While

strict OECD (Organization for Economic

Co-operation and Development) pass/

fail criteria are given in the OPPTS

Ready Biodegradability test guidelines

(see http://www.oecd.org//ehs/test/

degrad.htm and Testing Strategy for PBT

Chemical Substances, Unit IV.B. of this

document), the Agency recognizes the

limitations in applying such criteria
Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices 60197

rigidly given that many substances of

concern as potential PBTs are unlikely

to pass ready biodegradability tests. A

variety of critical aspects beyond the

pass/fail result will be considered when

evaluating potential new chemical PBTs

or when testing decisions are made

about specific PMN substances. These

more critical aspects include those

related to chemical structure (e.g.,

degree of branching) and bioavailability

(e.g., uptake of a substance by fish or

microorganisms), and their influence on

both biodegradation and

bioaccumulation.

C. Bioconcentration Factor and Kow

Comment 3-Bioconcentration factor.

Commenters requested clarification on

how bioconcentration factor (BCF) will

be estimated using calculations based

on octanol-water partition coefficient.

Response. The octanol-water partition

coefficient (Kow) is correlated with the

potential for a chemical to

bioaccumulate in organisms; the BCF

can be predicted from log Kow, via

computer programs based on structure

activity relationship (SAR). The Agency

process for predicting bioaccumulation

factors (BAFs) and BCFs, along with

literature references, is described in

some detail in the proposed rule for

lowering of reporting thresholds for

certain PBT toxic chemicals subject to

reporting under section 313 (Toxic

Release Inventory, or TRI) of the

Emergency Planning and Community

Right-to-Know Act (EPCRA) of 1986

(January 5, 1999 (64 FR 688) (FRL–

6032–3), see page 704).

Comment 4-Log Kow and low

solubility chemicals. Commenters

suggested that the October 5, 1998 (63

FR 53417) Federal Register notice

identified methods for calculating log

Kow that are not appropriate for organic

pigments, which are insoluble in

octanol. They wanted to know how EPA

handles low octanol or water soluble

chemicals.

Response. EPA believes that the

methods cited in the October 5, 1998 (63

FR 53417) Federal Register notice for

experimental measurement of the

octanol/water partition coefficient

(Kow), or SAR to predict Kow, are

appropriate, and the results of either can

then be used to predict the Fish BCF.

Chemicals are unlikely to be accorded

special treatment in the new chemicals

review process solely because of low

solubility in octanol or water alone. The

test guidelines (OPPTS 830.7570 or

830.7560) cited in the October 5, 1998

(63 FR 53417) Federal Register notice

are viewed as the most appropriate for

measuring Kow, and alternatively, the

shake-flask method (OPPTS 830.7550

test guideline) or the new ‘‘slow-stir’’

method currently under development by

the OECD, can be used. However, if the

chemical manufacturer still views these

methods as inappropriate for a given

chemical, it would be advisable to

proceed to more definitive testing to

address bioaccumulation potential (i.e.,

the Fish BCF study). This approach can

be applied to other testing endpoints as

well; for example, based on

physicochemical properties of a

particular PMN chemical substance, a

company might forgo a lower tier acute

Daphnia toxicity study in favor of the

chronic study because it would yield

the best information for the screening

level risk assessment.

Comment 5-Use of octanol solubility

data alone. Commenters wanted to

know if octanol or fat solubility data can

be used before determining which

chemical substances have the potential

for bioaccumulation.

Response. By itself, solubility in

octanol (as a surrogate for fat) is not a

good predictor of potential

bioaccumulation in fish. Kow is

correlated with the potential for a

chemical to bioaccumulate in

organisms; the bioconcentration factor

(BCF) can be predicted from log Kow,

via SAR. Kow is a coefficient which

serves as a surrogate for the partitioning

of chemicals between water and fat, and

cannot be accurately estimated via

separate determinations of solubility in

pure octanol and water (i.e., by

calculating the ratio of the pure-solvent

solubilities) (Sijm et al., 1999, see Unit

VI.1.). The Agency uses and

recommends the use of computer

models to predict Kow where there are

no measured data.

D. Environmental Half-Life

Comment 6-Calculation of half-life.

Commenters wanted to know how halflife is calculated in the review of PBT

new chemicals.

Response. Multimedia fate models

like the Environmental Quality Criteria

(EQC) model (Mackay et al., 1996, see

Unit VI.2.) require compartmental halflives for air, water, soil and sediment,

which cannot necessarily be interpreted

as half-lives for any specific process

such as biodegradation. Data on air halflives for input to models would be

either measured or derived from the

Atmospheric Oxidation Program (AOP

or AOPWIN) or similar methodology.

Studies by Boethling et al. (1995, see

Unit VI.3.) and Federle et al. (1997, see

Unit VI.4.) suggest that half-lives in bulk

soil may be assumed for screening

purposes to be about the same as for

surface water, and that sediment halflives may be assumed to be 3–4 times

longer. EPA’s current suggested

approach to finding water half-life is to

use the Ultimate Survey Model (USM)

in the EPI BIOWIN program (Boethling

et al., 1994, see Unit VI.5.). Estimation

of bulk compartment half-lives from

USM model data requires several

assumptions, including that (1)

biodegradation is the only significant

fate process in water, soil, sediment; (2)

water and soil half-lives are the same;

and (3) sediment is dominated by

anaerobic conditions and therefore

sediment half-life is four times longer

than water half-life.

E. Computer Models and the Use of

Models vs. Actual Data

Comment 7-Use of models vs. actual

data. Commenters support the use of the

Mackay/EQC model, but stressed the

importance of having a process for using

actual data in place of the model.

Response. This is a reasonable

suggestion. The EQC model is based on

the fugacity approach and subsequently

applied to numerous environmental

processes. It uses an ‘‘evaluative

environment’’ in which environmental

parameters such as bulk compartment

dimensions and volumes (e.g., total

area, volume of soil and sediment, etc.)

are standardized, so that overall

persistence for chemicals with different

properties and rates of transformation

may be compared on an equal basis. In

general, measured values of toxicity,

chemical properties, compartmental

transformation half-lives, etc., provided

the data are of acceptable quality, are

preferred over those that are predicted

or estimated via a model or computer

program.

Comment 8-Modeling of air releases.

Commenters noted that the October 5,

1998 (63 FR 53417) Federal Register

notice considered only biodegradation

and aqueous hydrolysis and asked about

fate of a chemical upon release to air.

They suggested that EPA estimate

atmospheric oxidation using AOPWIN.

Response. Although the testing

strategy for this policy statement focuses

on biodegradability, all relevant

transport and transformation processes

will be considered in evaluating the

potential for a PMN substance to behave

as a PBT. Transformation processes not

mentioned in the Federal Register

notice but which may be important for

specific PMN substances include

atmospheric oxidation and photolysis,

photolysis in water, and redox

transformations (of which there are

various types) in water, soil, and

sediment. Although EPA believes that

for most organic chemicals,

biodegradation in water, soil, and

sediment will be the most important
60198 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

transformation process, each suspected

PBT chemical substance will be

evaluated on its use and disposal

patterns.

Clearly the atmosphere is an

important environmental medium, and

is especially relevant where a substance

is emitted directly to the atmosphere or

transported there via volatilization or

aerosolization. We know by deduction

that it is only, or at least chiefly,

through the atmosphere that POPs like

dioxins and Polychlorinated biphenyls

(PCBs) reach remote locations, and it

will be an important factor in

determining the ultimate fate of many

PMN substances as well. It is through

multimedia fate models such as EQC

that atmospheric fate will be considered

in developing an overall prediction of

environmental persistence for suspected

PBT substances. Where measured data

are not available, appropriate estimation

methods such as that in the AOPWIN

program will be used to generate

screening-level estimates of atmospheric

half-lives.

F. Use of ‘‘Weight of Evidence’’ and

Professional Judgment

Comment 9-Laboratory vs. field

behavior of chemicals. Commenters

indicated that EPA needs to incorporate

any differences between lab and field

behavior of chemicals into its analysis

of new chemical substances,

acknowledge the limitations of

screening-level biodegradation tests,

and acknowledge the value of using

professional judgment when

interpreting data from extended (> 60

day) degradation studies.

Response. EPA recognizes that

laboratory tests at best provide a

snapshot of expected environmental

behavior, which ideally is studied in the

field. But since field testing is nearly

always impractical for PMN chemical

substances, it is necessary to conduct

laboratory tests and to apply scientific

judgment in extrapolating from lab to

field. EPA similarly acknowledges the

limitations of ready biodegradability

and other screening tests as indicators of

ultimate environmental behavior.

Finally, it is well known that even this

policy statement’s higher tier (Testing

Tiers 2 and 3) environmental fate

guidelines, despite being designed to

provide test conditions closer to those

expected in the field, become less

reliable when tests are run for longer

than the maximum duration specified in

the guidelines. EPA will give

appropriate weight to these and other

complexities in its assessments.

Comment 10-‘‘Check the box’’ vs.

‘‘weight of evidence.’’ Commenters

noted that the TSCA PMN requirements

for PBT chemicals look more like

‘‘check-the-box’’ than ‘‘weight of

evidence’’ and wanted to know how

EPA will make professional judgment

and use SAR and assessment methods to

identify PBT new chemicals.

Response. These tools (professional

judgment, SAR, computer models,

assessment methods, etc.) would be

applied to potential PBT chemical

substances in the same way they are

applied to any other chemical substance

in the PMN review process. Using

predictive tools (in the absence of test

data) and professional judgment, EPA

leans towards a ‘‘reasonable worst case’’

when there is lack of chemical-specific

data. Industry always has the option of

assisting and enhancing the Agency’s

determinations by submitting

scientifically valid test data. There are a

number of existing documents

describing the PMN process and the

critical role played by SAR and

professional judgment in that process,

including the Chemistry Assistance

Manual for Premanufacture Notification

Submitters (USEPA, 1997, see Unit

VI.6.) and parts of the report on the joint

U.S./European Union study that

evaluated the predictive power of the

SAR (USEPA, 1994, see Unit VI.7.). EPA

believes that, where no or insufficient

actual toxicity data exist upon which to

base a decision, toxicity estimates

generated by SARs and other predictive

techniques may constitute sufficient

evidence to be used in human health

and environmental hazard and

environmental fate assessment as

components in certain risk

determinations under TSCA (see also

the Federal Register of December 1,

1993 (58 FR 63507) for a similar

statement related to meeting section 313

listing criteria under EPCRA of 1986).

Comment 11-Implement PBT policy

within risk assessment framework.

Commenters suggested that EPA risk

management decisions should not be

made solely on hazard information;

these PBT criteria should be

implemented within a risk assessment

framework. They indicated that toxicity

has been largely overlooked in the PBT

scheme and no criteria have been

provided for toxicity. Commenters

suggested that EPA needs to take into

account P and B and T before requiring

further testing or identifying a chemical

as a ‘‘true’’ PBT, and asked whether

persistence and log Kow would be

sufficient to determine that a PBT PMN

chemical substance may pose a

significant risk. Commenters also

suggest that EPA should except nontoxic and low exposure/release

substances from consideration under

this category and were concerned that

the current proposed criteria do not

consider any health and safety benefits

of a PBT chemical substance.

Response. New chemicals identified

as potential PBT chemicals are assessed

on a case-by-case basis. Section 5(e) of

TSCA authorizes EPA to control

commercial activities involving a new

chemical substance for which available

information is insufficient to permit a

reasoned evaluation of potential health

and environmental effects if EPA

determines either (1) that the

manufacture (including import),

processing, distribution in commerce,

use, or disposal of the substance may

present an unreasonable risk of injury to

health or the environment (‘‘risk-based’’

finding), or (2) that the substance is or

will be produced in substantial

quantities, and such substance either

enters or may reasonably be anticipated

to enter the environment in substantial

quantities or there is or may be

significant or substantial human

exposure to the substance (‘‘exposurebased’’ finding). The restrictions under

TSCA section 5(e) are imposed pending

the development of the test data or other

information needed to evaluate the new

substance’s health or environmental

effects. EPA draws on information and

data submitted with the PMN form,

other information available to the

Agency, and modeling (e.g., exposure,

release, SAR, etc.).

The Agency will consider P and B and

T, individually and together, and

exposure in making risk-based

judgments. Risk, specific to the PMN

substance as well as its risk relative to

substitutes currently on the market, is

predicted as a function of the potential

hazard of the substance and the

expected exposure. In other instances,

as discussed in the October 5, 1998 (63

FR 53417) Federal Register notice,

during PMN review EPA may determine

that a new substance will be produced

in substantial quantities and ‘‘may

reasonably be anticipated to enter the

environment in substantial quantities or

there is or may be significant or

substantial human exposure to the

substance,’’ and that the available

information is insufficient to determine

the effects of the substance. For such

exposure-based determinations on

suspected PBT new chemicals, EPA will

use a case-by-case approach for making

findings by applying considerations

beyond P and B (i.e., toxicity or

physical/chemical properties), and

consider P and B aspects as factors

which might argue for regulatory action

under TSCA section 5(e) at lower levels

of production or exposure/release than

are described in the general guidelines

for the new chemicals program’s
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exposure-based policy (USEPA, 1988,

USEPA, 1989, see Unit VI.8. and 9.).

Overall, companies are not being

prevented from developing and using

new substances that are judged to be

potential PBT chemicals, but EPA may

require certain controls (e.g., limiting

the release of the PMN chemical to the

environment) or testing as a result of its

assessments.

In order to be so identified as a PBT

new chemical based on a risk-based

finding, all three criteria must be

satisfied. The Agency has adopted a 1 to

3 rating system for each of P, B, and T.

If chemical has a low Kow (i.e., ‘‘B1,’’

with BCF estimated as less than 1,000),

the B1 rating does not support the new

chemical’s identification as a potential

‘‘PBT chemical.’’ For example, some

surfactants could be P3B1T3; they are

highly persistent in the environment

and chronically toxic to organisms, but

with low bioaccumulation potential.

However, Agency action may still be

taken under TSCA on chemicals not

meeting all of the PBT criteria, if they

otherwise meet the risk or exposurebased elements of TSCA section 5(e).

Similarly, calcium would also not be

considered a PBT chemical, as it would

be ranked P3B3T1; it is persistent in the

environment, it bioaccumulates, but it is

not considered toxic. Although the

Agency does not promote the

environmental discharge of more

persistent materials, the environmental

‘‘desirability’’ of a given chemical often

depends on a balance of various factors,

including toxicity and ability of the

chemical to bioaccumulate. Like the

previous surfactant example, the

Agency may nonetheless take action on

a P3B3T1 chemical (not calcium per se),

most likely under its exposure-based

authority.

The toxicity rating for a PBT chemical

applies to repeated exposures which

result in human or environmental

toxicity, including, for example,

systemic toxicity, mutagenic damage,

reproductive toxicity, or developmental

toxicity. An example of this is chronic

toxicity towards aquatic organisms of

organotins from contaminated marine

environments, which ultimately

resulted in the regulation of use of

tributyl tin in marine anti-fouling

paints. Repeated exposures result from

a PBT chemical after it has been

released into the environment, usually

via contaminated water, sediments, or

food. The classic PBT problems (i.e.,

PCBs and Dichloro diphenyl

trichloroethane (DDT)) have been

associated with food chain

contamination.

G. Scientific Justification for PBT

Technical Criteria

Comment 12-Support for lower

threshold criteria for ‘‘P’’ and ‘‘B.’’

Commenters believed that there is little

precedent, scientific justification,

evidence or data to support the lower

regulatory threshold of bioaccumulation

factor of 1,000 and environmental

persistence of 2 months. They suggested

that EPA needs a rationale for these

criteria beyond ‘‘...are characterized by

a tendency to accumulate in

organisms.’’

Response. There is no ‘‘bright line’’

that clearly identifies a bioaccumulation

factor of 1,000 or a half-life of 2 months

as the best bioaccumulation or

persistence criterion from a scientific

perspective. However, it is not accurate

to state that there is no precedent or

basis for using these values. As outlined

in EPA’s recent proposal to lower the

reporting thresholds for PBT chemicals

that are subject to reporting under

section 313 of EPCRA (64 FR 688;

January 5, 1999), similar values have

been proposed by several authorities,

including the Ontario, Canada Ministry

of Environment and Energy (MOEE) for

its Candidate Substances List for Bans

or Phaseouts (MOEE, 1992, see Unit

VI.10.); the Canadian initiative for

Accelerated Reduction/Elimination of

Toxics (ARET) (ARET, 1995 and ARET,

1994, see Unit VI.11. and 12.); the

International Joint Commission (IJC)’s

Great Lakes Water Quality Agreement

(GLWQA) (IJC, 1993, see Unit VI.13.);

and the United Nations Economic

Commission for Europe Convention on

Long-Range Transboundary Air

Pollution (UNECE-LRTAP), which did

adopt 2 months as the persistence

criterion of record for water (UNECELRTAP, 1998, see Unit VI.14.).

In determining the thresholds for this

policy statement, EPA concluded that it

would be appropriate to reflect the

levels of concern that the various PBT

chemicals presented, based on the

differing degrees to which the chemicals

persist and bioaccumulate. The Agency

ultimately chose to adopt a two-tier

approach, and to establish two separate

thresholds to reflect the chemicals’

varying potentials to persist and

bioaccumulate, as well as to reflect the

Agency’s belief that the different levels

of regulatory action under TSCA are

warranted for the two tiers. As

discussed in detail in the preamble to

the mentioned EPCRA proposed rule,

EPA found that generally the criteria

selected by various U.S. and

international regulatory bodies for either

persistence or bioaccumulation

clustered around two values. For

persistence in water, soil, and sediment,

the criteria were grouped around halflives of 1 to 2 months and 6 months,

and for persistence in air, either 2 or 5

days. Bioaccumulation criteria were

grouped around BAF/BCF values of

1,000 and 5,000. The preamble to the

EPCRA proposed rule states ‘‘Bearing in

mind that one of Congress’ articulated

purposes for EPCRA section 313 was to

provide local communities with

relevant information on the release and

other waste management activities of

chemicals in their community that may

present a hazard, EPA determined that

the criteria that were most consistent

with these purposes were, for

persistence, half-lives of 2 months for

water, sediment, and soil, and 2 days in

air, and for bioaccumulation,

bioaccumulation/bioconcentration

factor values of 1,000 or greater’’ (64 FR

692; January 5, 1999). EPA is making a

similar determination for the PBT new

chemicals policy under TSCA. The

PMN process is one of EPA’s

cornerstone Pollution Prevention

programs and plays a critical gatekeeper

role in making sure that all new

chemical substances do not present

unreasonable risks when they are

commercialized. Given this, and the

uncertainty which often accompanies

Agency review of a PMN chemical

substance due to lack of data, the TSCA

new chemicals program is and must be

conservative by nature, which suggests

that a half-life shorter than 6 months

and a BCF criterion lower than 5,000—

values that were selected solely or

primarily to isolate substances already

widely acknowledged to be POPs are

appropriate for regulatory scrutiny of

new chemicals under TSCA. Note that

the CEG, at the October 26–30, 1998

Bangkok meeting described in Unit II.B.

of this document, developed indicative

numerical values as bracketed criteria

text which included persistence of 2 vs.

6 months in water and log Kow of 4 vs.

5 (equivalent to a BCF of approximately

1,000 vs. 5,000, respectively).

A series of PMNs submitted to EPA in

1990 (Zeeman et al., 1999, see Unit

VI.15.) illustrates (1) why EPA believes

that the persistence criterion for

bioaccumulating substances in soil,

water, or sediment should be set

substantially lower than 6 months; and

(2) that concern for potential exposures

to persistent and bioaccumulative toxics

must extend beyond the UNEP’s 12

widely acknowledged POPs. The

substances in question were alkylated

diphenyls, for which EPA expected

discharge to receiving streams and

rivers. The submitter supplied data on

use and disposal, aquatic toxicity, and
60200 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

biodegradability. The submitted

environmental fate data and EPA

estimates of biodegradability based on

structural analogs suggested that halflives in water would be well below 6

months, but not necessarily lower than

2 months. As a result of concerns

expressed by EPA, use was limited to

sites where resulting water

concentrations could be limited to 1

microgram per liter or less;

concomitantly, the submitter was also

informed of EPA’s belief that a potential

for long-term risk existed, but that EPA

could not quantify this risk since

assessments typically evaluated releases

over a period of only 1 year. In 1998,

results of monitoring revealed that the

PMN substances had been found in fish

fillets and sediment samples from the

receiving stream. If, for these 1990

PMNs, EPA were to have had in place

the 2 month persistence criterion

described in today’s policy statement,

further scrutiny under the new

chemicals program would have been

warranted, and beyond simply

informing the PMN submitter of the

potential for long-term risk, the Agency

would likely have required further

testing to obtain an experimental value

for environmental persistence of the

chemicals. This in turn would have

given the Agency a better picture of the

behavior of the chemicals in the

environment and the environmental

half-life relative to the 2 month value.

Comment 13-Deny commercialization

to lower threshold PBT chemicals. Some

commenters supported exercising the

‘‘Precautionary Principle’’ by not

allowing commercialization under a

TSCA 5(e) consent order or SNUR

pending testing of the PMN chemicals

which meet the P=2 month and

BCF=1,000 criteria. They suggested that

these chemicals should be banned

instead, pending the necessary testing.

Response. Whereas a half-life of 2

months and BCF of 1,000 can be

justified as lower-tier cutoffs in a

deliberately conservative TSCA new

chemicals program that is designed to

prevent commercialization of

potentially risky substances, it would

not be appropriate to automatically

trigger a ‘‘ban pending testing’’ at these

cutoffs given the uncertainties about

substance properties, release, and

environmental behavior that normally

characterize PMN review. The Agency

believes that the available predictive

tools and current knowledge of POPs

lend support for this two-phased

approach to screening of PBT chemicals

and collection of information ‘‘sufficient

to permit a reasoned evaluation of

potential health and environmental

effects’’ if EPA makes the requisite riskor exposure-based findings under TSCA

section 5(e).

Comment 14-Relationship of P, B, and

T criteria. Commenters suggested that

the October 5, 1998 (63 FR 53417)

notice is inaccurate when it states that

2 months is adequate for detecting many

long-term toxic effects as well as any

tendency for a substance to

bioaccumulate in aquatic organisms.

Commenters pointed out that the

persistence criterion is not related to

detection of long-term toxicity.

Response. The statement in question

was intended simply to note that the 2

months half-life in water persistence

criterion closely tracks the duration of

long-term environmental toxicity or

bioaccumulation tests. If a new

chemical substance is predicted to or

measurably demonstrates chronic

toxicity, potential to bioaccumulate, and

environmental persistence over that

same time period (2 months), it would

meet the minimum TSCA PBT criteria.

It is true that, in general, half-life cutoffs

for identifying POPs warranting

international action (e.g., in programs

like UNECE-LRTAP and UNEP Global

Negotiations on POPs) have not been

selected based on the duration of

toxicity or bioaccumulation tests. There

are no cutoffs or ‘‘fence lines’’ for

environmental persistence criteria that

emerge as immutable quantities solely

from scientific analysis; the choice of

screening criteria is a policy decision

guided by the anticipated scope of a

negotiation or regulatory activity. In the

case of the PMN program, 2 months

represents a reasonable screening level

value for ‘‘persistence’’ which is more

than the 1-month period in a ready

biodegradation study and less than the

6 month value widely agreed to

internationally (U.S.-Canada binational

agreement to control the discharge or

release of POPs in the Great Lakes

Basin, UNECE-LRTAP, North American

Free Trade Agreement Commission for

Environmental Cooperation (NAFTACEC), etc.) as reflecting the persistence

of known POPs chemicals (e.g., DDT,

hexachlorobenzene). As mentioned in

the previous response, there is

international support, through the CEG,

for persistence values of 2 or 6 months

in water.

Comment 15-Relationship of P and B.

Commenters suggested that the October

5, 1998 (63 FR 53417) notice’s

statement, ‘‘Generally, persistent

bioaccumulators are chemical

substances that partition to water,

sediment or soil and are not removed at

rates adequate to prevent their

bioaccumulation in aquatic or terrestrial

species,’’ should be revised to reflect

that persistence alone is not sufficient to

cause a substance to bioaccumulate.

Response. EPA did not intend that the

sentence be read to mean that

persistence alone is sufficient to result

in bioaccumulation. The point that was

intended to be conveyed was that a

certain level of persistence is a

necessary condition for

bioaccumulation to occur. There are

other conditions that affect

bioaccumulation, such as bioavailability

and the metabolic transformation rate in

the target species. These and other

factors will be evaluated by EPA in the

determination of the PBT concern level

for PMN chemical substances.

H. Relationship of TSCA PBT Policy to

Other Agency and International PBT

Initiatives

Comment 16-Finalize overall Agency

multimedia strategy first. Commenters

suggested that the PBT classification

criteria being proposed for TSCA

section 5(e) may have broader

application, e.g., international or other

Agency PBT initiatives, and may be

used to establish precedent in other

programs. In addition to the TSCA

October 5, 1998 (63 FR 53417) Federal

Register notice, there have been three

other notices published in Federal

Register dealing with (1) the promotion

of voluntary waste minimization efforts

to reduce the generation of those PBT

chemicals which are found in hazardous

waste regulated under the Resource

Conservation and Recovery Act (RCRA)

(63 FR 60332; November 9, 1998 (FRL–

6186–7)), (2) the Agency draft

Multimedia PBT Strategy (63 FR 63926;

November 17, 1998 (FRL–6045–2)), and

(3) the lowering of reporting thresholds

for certain PBT toxic chemicals subject

to reporting under section 313 (Toxic

Release Inventory, or TRI) of EPCRA of

1986 (64 FR 688; January 5, 1999).

These commenters stated that the TSCA

notice is premature, occurring before

adoption of the overall Agency strategy,

and is inconsistent with other

initiatives, domestic and international,

which have lists of chemicals and more

selective criteria (i.e., specific to

environmental media, fate and

transformation processes). Commenters

recommended that EPA finalize the

Agency strategy first, before proceeding

with the TSCA, RCRA, and TRI actions,

and that there should be coordination

among them all with uniform PBT

criteria as part of the Agency strategy.

Response. The PBT Multimedia

Strategy formalizes an Agency process

for integration of program activities

involving these types of substances.

While the strategy intends to coordinate

Agency PBT-related activities under its
Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices 60201

framework, the strategy does not

establish rigid criteria with respect to

PBTs. Program offices must operate

within the parameters of their legislative

mandates and established regulatory

and policy frameworks. For some

programs such as the Toxics Release

Inventory, the TSCA New Chemicals

Program and the RCRA National Waste

Minimization Plan, actions involving

PBTs are a historical reality and their

experience has, in fact, largely shaped

the strategy. Therefore, EPA does not

intend to halt all ongoing work

involving PBTs until the strategy is

‘‘finalized.’’ With respect to the PMN

process, it is important to understand

and acknowledge its fundamental

purpose, which is to allow EPA to

evaluate the hazards, exposures, and

risks of new chemicals, and the

opportunity to protect against

unreasonable risks, if any. The structure

of that process and the tools used to

implement it flow logically from its

statutory purpose and suggest that the

category approach outlined in this

policy statement is the most appropriate

means of addressing potential concerns

for substances possessing PBT

characteristics. It is EPA’s intention that

the strategy be a living document.

Therefore, the strategy will be updated

based upon public comment; it will not

be ‘‘finalized’’ in the more traditional

sense of a rulemaking. EPA does agree

that consistency is a laudable goal

where the criteria are meant to be used

for similar purposes and is seriously

considering comments within the

context of the strategy regarding

establishment of consistent criteria for

priority PBTs.

Comment 17-Carefully communicate

lower thresholds. Commenters suggested

that EPA should use only the

environmental persistence of 6 months/

BCF of 5,000 screening levels for

consistency among EPA and U.S./

international programs and should

carefully communicate proposed lower

criteria internationally.

Response. As discussed in the

response to Comment 12, EPA believes

that a lower tier of 2 month/BCF of

1,000 is appropriate for risk screening

activities under TSCA. Communication

is occurring in the international forum.

Unit II.B. of this document discusses the

CEG for POPs, established under UNEP

mandate. At its first meeting, on October

30, 1998 in Bangkok, the CEG

recommended that the INC consider

developing a provision encouraging

countries and regions to include in their

new chemicals schemes elements

relating to development and

introduction of new chemical POPs. The

U.S. described its proposed TSCA new

chemicals program policy for the

category of PBT new chemicals, and the

full text of the October 5, 1998 (63 FR

53417) Federal Register notice was

distributed to all delegations as a

Conference Room Paper. The CEG’s

recommendation was accepted at the

second meeting of the INC (January 25–

29, 1999 in Nairobi) and the INC will

consider it further in its deliberations.

I. Testing Strategy

Comment 18-Toxicity testing.

Commenters asked whether toxicity was

considered at each testing tier or only in

tier 3. It was not clear to them when

toxicity testing would be requested, nor

what results will be considered

acceptable by the Agency.

Response. Each of P and B and T are

weighed in the Agency’s assessment.

The testing strategy outlined in this

policy statement is intended to build the

case, starting with testing to establish

persistence and bioaccumulation, and

then determining toxicity and

confirming a chemical’s status as a PBT

chemical in tier 3. Once a chemical

becomes distributed in the environment

at low concentrations, the combination

of persistence and bioconcentration in

organisms can result in residues high

enough to approach a toxic dose. The

first two tiers focus on P and B because

of the critical role these aspects play in

PBT determinations and because of their

relatively lower cost to determine P and

B. Thus, chronic toxicity testing, which

is expected to be the most expensive

testing, is reserved until tier 3 where it

serves to establish PBT status. Although

the early tier P and B testing may either

obviate the need for toxicity testing or

result in more directed and costeffective toxicity testing, the need for

toxicity testing is considered in each

testing tier and will be obtained in

lower tiers where needed on a casespecific basis. As with all new

chemicals reviewed by the Agency

under TSCA, the potential toxicity of

the chemical is determined from test

data, if any, or by analogy to structurally

similar chemicals. If a company knows

or suspects prior to testing that their

chemical is likely to be persistent and

bioaccumulative, consideration should

be given to conducting chronic toxicity

testing in the first tier. For any

suspected PBT chemicals for which a

risk finding has not been made, but

which meet production, release, and

exposure thresholds under the Agency’s

exposure-based policy (USEPA, 1988,

USEPA, 1989, see Unit VI.8. and 9.), the

standard screening level battery of

testing (or an appropriate subset thereof)

currently utilized for exposure-based

cases in the new chemicals program

could be required in addition to PBT

testing.

Comment 19-Equivalent tests.

Commenters suggested that all tests

referenced in the testing strategy should

also state ‘‘or an equivalent test.’’

Response. EPA realizes that often

there are a number of different but

acceptable means to providing testing

information. However, EPA’s

acceptance of a guideline not specified

in this policy statement and/or use of

data generated under such guidelines

depends on multiple factors including

the specifics of the test substance,

purpose of the testing, familiarity with

specific procedures and equipment,

validation of the method, etc. Typical

TSCA 5(e) consent orders require that

testing performed pursuant to the order

must be conducted according to TSCA

Good Laboratory Practice Standards at

40 CFR part 792 and using

methodologies generally accepted at the

time the study is initiated. Before

starting to conduct any such study, the

PMN submitter must obtain approval of

test protocols from EPA by submitting

written protocols. Published test

guidelines specified in the Test Strategy

section (see Unit IV. B. of this

document) provide general guidance for

development of test protocols, but are

not themselves acceptable protocols.

J. Applicability of PBT Criteria to Metals

Comment 20-PBT criteria are not

appropriate for metals. Commenters

suggested that the application of

Persistence and Bioaccumulation

criteria appropriate for organic

chemicals does not make sense for

metals and metal compounds. They also

suggested that EPA needs criteria to

identify potential problems generated by

organometals.

Response. The approach and the

criteria are sufficiently flexible to apply

to organic chemicals, inorganic metals

and organometallics. It is important to

distinguish between criteria for

identifying potential PBTs, on the one

hand, and on the other: (1) the means of

generating information on the P, B, and

T endpoints for comparison to the

criteria, and (2) the applicability of

existing test guidelines for generating

such information experimentally.

EPA understands that metals are

intrinsically not degradable in the sense

of ultimate degradation of organics

(although they may undergo biologically

as well as chemically induced changes

in, e.g., oxidation state), and therefore

are persistent by definition, but

nevertheless may not be

bioaccumulative. It is widely accepted

that elemental metals are persistent by

definition, since they may take different
60202 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

forms that can be interconverted, but the

elemental metal itself cannot be

destroyed. All elemental metals

therefore meet the 6 month half-life

criterion. Given this, it is not correct

that EPA’s proposed persistence criteria

cannot be applied to metals. It may be

more accurate to state that the

persistence criteria are not themselves

very helpful in screening or assessing

metals and metal compounds with

respect to the potential for risk, whether

from direct exposure or through

bioaccumulation. Relative to

applicability of test guidelines, the same

level of judgment will be brought to bear

such that, for example, EPA would not

require ready biodegradability testing

for a metal or metal salt. (EPA may,

however, request such testing for

organometallics, which, depending on

chemical structure, could still show

significant degradation in such tests.)

EPA understands that bioavailability

is important in determining the

potential for risk, and notes that the

same generalization applies to any

substance whether metallic or not.

Metals and organometallic compounds

are no different from other organic

chemicals with respect to the

applicability of the proposed criteria for

identifying persistent, bioaccumulative,

and toxic substances, except that Kow

determination may not be relevant for

metals (although the fish BCF study is

relevant). Similarly, it is not necessary

to develop different criteria or

assessment strategies for pigments (see

first comments/responses in this policy

statement) or any other specific classes

of organics. What is necessary is to

consider what is known about the

behavior of substances like metals

during the TSCA PMN review process,

both in the assessment of whether a

given chemical substance meets the

established criteria and in subsequent

testing decisions. For any untested PMN

chemical substance, if there are no close

analogs with data and no clear evidence

that available estimation methods are

unreliable for this or closely related

substances, then the estimation methods

can be assumed to apply and the

resulting data compared to PBT criteria.

Put another way, a metal or

organometallic (or, similarly, a pigment)

that is judged sufficiently persistent and

meets the criteria for bioaccumulation

potential and toxicity is of concern for

‘‘PBTness’’ regardless of theoretical

arguments or generalizations.

The key is how persistence and

bioaccumulation potential are

determined in the PMN process, and by

implication, how bioavailability is

determined. This policy statement

leaves unspecified how EPA intends to

do this, but the Agency will consider all

available and relevant data, and will use

its professional judgment in considering

issues like bioavailability of metals.

Using lead as an example, many

processes commonly observed in the

environment can result in the presence

of bioavailable (ionic) lead where it can

be bioaccumulated by organisms. These

processes may occur in soil and aquatic

environments with low pH and low

levels of organic matter. Under these

conditions, the solubility of lead is

enhanced and, in the absence of sorbing

surfaces and colloids, lead ion can

remain in solution for a sufficient

period to be taken up by biota. Lead

sorption to soil organic matter has been

shown to be pH dependent. Decreasing

pH can lead to increasing

concentrations of lead in soil and water.

Microbial transformations in soil, water,

and sediment are also important in

determining the overall fate of metals

and metal compounds, and therefore the

potential for formation of bioavailable

forms. Metals are generally taken into

cells by nutrient metal transport

systems, and these are not sufficiently

specific to completely exclude

nonessential metals, some of which may

be toxic and/or bioaccumulative. In this

situation, nutrient metals can be

displaced from their binding sites by

undesirable, toxic metals, which then

gain access to the cell interior with

concomitant exclusion of the essential

metal (Stumm and Morgan, 1996 see

Unit VI.16.). Toxic metal ions are then

free to react with critical enzymes or

otherwise disrupt cellular functions if

they reach certain levels. EPA concludes

that under many environmental

conditions, metals and metal

compounds may be available to express

toxicity and to bioaccumulate, and that

these effects are not necessarily limited

to metals that are not essential nutrients.

It is appropriate, therefore, to be

concerned about the potential for risk

from these effects. It is the policy of the

TSCA New Chemicals Program that if

the metal in a metal compound cannot

become available as a result of biotic or

abiotic processes then the metal will not

be available to express its toxicity, and

by extension, to bioaccumulate. If the

intact metal compound is not toxic and

the metal is not available from the metal

compound, then such a chemical would

not be a strong candidate for regulation

under TSCA section 5(e).

IV. Final TSCA New Chemicals

Program Policy for PBT Chemical

Substances

A. Evaluation Criteria and Process for

New PBT Chemical Substances

EPA is adopting the following specific

identification criteria and associated

process for use in evaluating new

chemical substances.

NEW CHEMICALS PROGRAM PBT

CATEGORY CRITERIA AND PROCESS

TSCA Section 5(e) Action

5(e) Order

Pending Testing/Significant

New Use Rule

(SNUR)1

5(e) Ban

Pending

Testing2

Persistence

(transformation

half-life).

> 2 months ...... > 6 months

Bioaccumulation

(Fish BCF

or BAF)3.

≥ 1,000 ............ ≥ 5,000

Toxicity ....... Develop toxicity

data where

necessary4.

Develop toxicity data

where

necessary4

1Exposure/release controls included in

order; testing required. 2Deny commercialization; testing results

may justify removing chemical from ‘‘high risk

concern’’. 3Chemicals must also meet criteria for MW

(< 1000) and cross-sectional diameter (< 20A ̊ ,

or < 20 × 10-8 cm). 4Based upon various factors, including concerns for persistence, bioaccumulation, other

physical/chemical factors, and toxicity based

on existing data.

Chemical substances suspected as

persistent bioaccumulators under the

criteria listed in the table in Unit IV.A.

of this document may need to undergo

testing on ‘‘P’’ and ‘‘B’’ endpoints

which, if confirmed, would be followed

by appropriate toxicity testing to

identify ‘‘PBT chemical substances.’’

Control action under TSCA section 5(e)

may be needed in varying degrees,

based upon the level of risk concern.

Agency control actions taken under

TSCA section 5(e) for chemical

substances meeting these criteria would

be based upon the level of certainty for

the PBT properties of a PMN substance

(e.g., measured vs. estimated values),

the magnitude of Agency concerns, and

conditions of expected use and release

of the chemical. For example, new

chemical substances meeting the PBT

criteria listed under ‘‘5(e) Order Pending

Testing/Significant New Use Rule

(SNUR)’’ could be addressed via a

negotiated consent agreement under
Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices 60203

which necessary testing is ‘‘triggered’’

by specific production limits. While the

PMN submitter would be allowed to

commercialize the substance, certain

controls could be stipulated, including

annual TRI-type reporting on

environmental releases of the PMN

substance and specific limits on

exposures, releases, or uses. The ‘‘ban

pending testing’’ criteria are equivalent

to those that have been used

internationally to identify POPs. For the

chemical substances meeting these

criteria, the concern level is higher and

the Agency would look carefully at any

and all environmental releases. Because

of the increased concern, more stringent

control action would be a likely

outcome, up to a ban on commercial

production until data are submitted

which allow the Agency to determine

that the level of risk can be

appropriately addressed by less

restrictive measures. The control actions

described in the table in Unit IV.A. of

this document represent just one body

of possible decisions and should not be

considered as exclusive of other risk

management options.

B. Testing Strategy for PBT Chemical

Substances

Where EPA is unable to adequately

determine the potential for

bioaccumulation, persistence in the

environment, and toxicity which may

result from exposure of humans and

environmental organisms to a possible

PBT chemical substance, the Agency

may conclude, pursuant to sections

5(e)(1)(A)(i) and 5(e)(1)(A)(ii)(I) and (II)

of TSCA, that the information available

to the Agency is insufficient to permit

a reasoned evaluation of the human

health and environmental effects of that

PMN substance, that the manufacturing,

processing, distribution in commerce,

use, or disposal of the substance may

present an unreasonable risk of injury to

human health or the environment, and/

or that the PMN substance will be

produced in substantial quantities and

that there may be significant or

substantial human exposure to the

substance or the PMN substance may

reasonably be anticipated to enter the

environment in substantial quantities.

Accordingly, the Agency may find it

appropriate to prohibit or otherwise

limit the manufacture, import,

processing, distribution in commerce,

use, or disposal of the PMN substance

in the United States pending the

development of information necessary

for a reasoned evaluation of these

effects. The following testing strategy

describes test data which EPA believes

are needed to evaluate the persistence,

bioaccumulation, and toxicity of a PBT

chemical substance for which EPA has

made the above described risk and/or

exposure-based findings under section

5(e)(1)(A)(i) and (ii) of TSCA. The tests

are tiered; depending upon the

circumstances, such as magnitude of

environmental releases, results of

testing, or SAR, testing could begin

above Tier 1 or additional, higher levels

of testing may be required. As discussed

in the response to Comment 19 in Unit

III.I. of this document, testing must be

conducted according to TSCA Good

Laboratory Practice Standards at 40 CFR

part 792 and using methodologies

generally accepted at the time the study

is initiated. Before starting to conduct

any such study under the terms of a

Consent Order under TSCA section 5(e),

the PMN submitter must obtain

approval of test protocols from EPA by

submitting written protocols. Published

test guidelines specified in Unit IV.B. of

this document provide general guidance

for development of test protocols, but

are not themselves acceptable protocols.

Tier 1. If, based upon available test

data, SAR, and professional judgment,

the Agency identifies a new chemical

substance as a possible PBT chemical

substance, Log Kow should be

determined experimentally, using either

the liquid chromatography (OPPTS

830.7570 test guideline) or generator

column (OPPTS 830.7560 test guideline)

method. Hydrolysis in water (OPPTS

835.2110 test guideline) should be

determined if, based upon SAR,

susceptibility to hydrolysis is suspected.

Ready biodegradability should be

determined according to either one of

the following test guidelines:

1. Ready biodegradability (OPPTS

835.3110 test guideline) 6 methods

(choose one): DOC Die-Away, CO2

Evolution, Modified MITI (I), Closed

Bottle, Modified OECD Screening,

Manometric Respirometry.

2. Sealed-vessel CO2 production test

(OPPTS 835.3120 test guideline).

If the measured log Kow is < 4.2

(equivalent to an estimated BCF of

1,000) or if the test chemical passes

(pass criteria are described in the test

guidelines) the ready biodegradability

test (i.e., not persistent in the

environment), no further PBT-related

testing is required. If the measured log

Kow is greater than or equal to 4.2, and

the chemical does not pass the ready

biodegradability test, no further testing

will normally be deemed necessary in

tier 1; the Agency would likely require

tier 2 testing. If hydrolysis testing is

conducted and results in a half-life of <

60 days, further testing may not be

needed, but the need for testing must be

determined after consideration of factors

specific to the case, such as physical/

chemical properties, persistence and

bioaccumulative qualities of hydrolysis

products, and the nature of the expected

releases.

Tier 2. Biodegradability should be

determined according to the Shake-flask

die-away test (OPPTS 835.3170 test

guideline). This test is based on the

principle of aerobic incubation of the

test chemical in natural water with and

without suspended sediment, requires a

chemical-specific analytical method,

and allows for the development of a

first-order rate constant and half-life. It

provides information on persistence that

is relevant to the natural environment

and is intermediate in cost between

ready biodegradability tests (tier 1) and

sediment/water microcosm

biodegradation test (tier 3).

Bioaccumulation potential should be

determined by experimental

measurement of the bioconcentration

factor (BCF), using the Fish

bioconcentration test (OPPTS 850.1730

test guideline (public draft)). Measured

BCF should be based on 100 percent

active ingredient and measured

concentration(s).

If the measured biodegradation halflife is > 60 days and measured BCF is

> 1,000, tier 3 testing will normally be

required. If only one condition is met,

releases and exposure are further

considered to determine if additional

testing is required.

Tier 3. Toxicity/advanced

environmental fate testing. Human

health hazards should be determined in

the combined repeated dose oral

toxicity with the reproductive/

developmental toxicity screening test

(OECD No. 422 test guideline) in rats.

Other health testing will be considered

where appropriate.

Environmental fate testing should be

conducted according to the Sediment/

water microcosm biodegradation test

(OPPTS 835.3180 test guideline). The

principle of this method is the

determination of the test chemical’s fate,

including transport and transformation,

in core chambers containing intact

benthic sediment and overlying site

water. The method permits more

accurate and reliable extrapolation to

natural aquatic environments than is

possible with lower tier test methods.

Chronic toxicity to fish (rainbow

trout) and daphnids should be

determined according to 40 CFR

797.1600 (same as OPPTS test guideline

850.1400 (public draft)) and 40 CFR

797.1330 (same as OPPTS test guideline

850.1300 (public draft)), respectively.

Additional testing to evaluate other

biota (e.g., avian, sediment dwelling

organisms) or other effects (e.g.,
60204 Federal Register / Vol. 64, No. 213 /Thursday, November 4, 1999 / Notices

endocrine disrupting potential) will be

considered where appropriate.

V. Intended Legal Affect of this Policy

Statement

The policy discussed in this

document provides general guidance on

the Agency’s use of a category grouping

for PBT new chemical substances to

facilitate the PMN assessment process

for PMN submitters and EPA reviewers.

EPA uses groupings of new chemical

substances with similar structural and

toxicological properties to allow PMN

submitters and EPA reviewers to benefit

from accumulated data and decisional

precedents, as well as streamlined

procedural requirements related to the

review of and follow-up for new

chemical substances.

As guidance, the policy presented in

this document is not binding on either

EPA or any outside parties, and this

document is not intended, nor can it be

relied upon, to create any rights

enforceable by any party in litigation

with the United States. Although this

guidance provides a starting point for

assessing PBT new chemical substances,

EPA will depart from its policy where

the facts or circumstances warrant. In

such cases, EPA will explain why a

different course was taken. Similarly,

outside parties remain free to assert that

this policy is not appropriate for a

specific PMN or that the circumstances

surrounding a specific PMN

demonstrate that this policy should not

be applied. Although the Agency has

provided an opportunity for public

comment on the guidance provided in

this policy statement and is likely to

request additional feedback if changes

are necessary at some point in the

future, the Agency may revise, clarify,

or update the text of this guidance

without public notice.

VI. References

The OPPTS harmonized test

guidelines referenced in this document

are available on EPA’s World Wide Web

site (http://www.epa.gov/

OPPTS¥Harmonized/).

1. Sijm, D.T.H.M., Schuurmann, G.,

de Vries, P.J., Opperhuizen, A. Aqueous

Solubility, Octanol Solubility, and

Octanol/Water Partition Coefficient of

Nine Hydrophobic Dyes. Environ.

Toxicol. and Chem. 18:1109–1117.

2. Mackay, D., Di Guardo, A.,

Paterson, S., Cowan, C.E. 1996.

Evaluating the environmental fate of a

variety of types of chemicals using the

EQC model. Environ. Toxicol. Chem.

15:1627–1637.

3. Boethling RS, PH Howard, JA

Beauman and ME Larosche. 1995.

Factors for intermedia extrapolation in

biodegradability assessment.

Chemosphere 30: 741–752.

4. Federle TW, SD Gasior and BA

Nuck. 1997. Extrapolating

mineralization rates from the ready CO2

screening test to activated sludge, river

water, and soil. Environ. Toxicol. Chem.

16: 127–134.

5. Boethling RS, Howard PH, Meylan

W, Stiteler W, Beauman J, Tirado N.

1994. Group contribution method for

predicting probability and rate of

aerobic biodegradation. Environ. Sci.

Technol. 28: 459–465.

6. USEPA. March, 1997. Chemistry

Assistance Manual for Premanufacture

Notification Submitters. EPA 744–R–

97–003. Also available as

Premanufacture Notification: Chemistry

Assistance for Submitters, by Steven C.

DeVito and Carol A. Farris (ISBN: 0–

471–19151–5) through the publisher,

John Wiley and Sons, at 1–800–225–

5945 or the TSCA Hot Line, at 202–554–

1404.

7. USEPA. March, 1994. U.S. EPA/EC

Joint Project on the Evaluation of

(Quantitative) Structure Activity

Relationships. EPA 743–R–94–001.

8. USEPA. 1988. Letter from Charles

L. Elkins to Geraldine V. Cox (Chemical

Manufacturers Association). Office of

Toxic Substances, USEPA (September

22, 1988).

9. USEPA. 1989. Letter from Charles

L. Elkins to Geraldine V. Cox (Chemical

Manufacturers Association). Office of

Toxic Substances, USEPA (August 31,

1989).

10. Ministry of Environment and

Energy for Ontario (MOEE). 1992.

Candidate substances list for bans or

phase-outs. Report perpared by the

Hazardous Contaminants Branch and

the Water Resources Branch, MOEE.

Ontario, Canada, ISBN 0–7729–9764–0.

11. Accelerated Reduction/

Elimination of Toxics (ARET)

Secretariat. 1995. Environment leaders

1. Voluntary commitments to action on

toxics through ARET. March 95.

12. Accelerated Reduction/

Elimination of Toxics (ARET)

Secretariat. 1994. The ARET substance

selection process and guidelines.

January 94.

13. International Joint Commission

(IJC). 1993. A strategy for the virtual

elimination of persistent toxic

substances. Vol. 1, report of the Virtual

Elimination Task Force to the IJC.

Windsor, Ontario, Canada, 72 pp.

14. United Nations Economic

Commission for Europe, Convention on

Long-Range Transboundary Air

Pollution (UNECE-LRTAP). 1998. Draft

composite negotiating text for a protocol

on persistent organic pollutants.

UNECE, EB.AIR/1998/2, 31 March 1998.

15. Zeeman, M., D Rodier, and JV

Nabholz. 1999. Chapter 2. Ecological

Risks of a New Industrial Chemical.

Under TSCA. In Ecological Risk

Assessment in the Federal Government

(Executive Office of the President,

National Science and Technology

Council, Committee on Environment

and Natural Resources, Ed.). CENR/5–

99/001, May, 1999, pp 2–1 to 2–30.

16. Stumm, W. and JJ Morgan. 1996.

Aquatic Chemistry, 3rd ed. New York:

Wiley.

List of Subjects

Environmental protection, Chemical

substances, Hazardous substances,

Reporting and recordkeeping

requirements.

Dated: October 22, 1999.

Susan H. Wayland,

Deputy Assistant Administrator for

Prevention, Pesticides and Toxic Substances.

[FR Doc. 99–28888 Filed 11–3–99; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–6469–6]

Notice of Proposed Assessment of

Clean Water Act Class II Administrative

Penalty and Opportunity To Comment

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice.

SUMMARY: EPA is providing notice of a

proposed administrative penalty for

alleged violations of the Clean Water

Act. EPA is also providing notice of

opportunity to comment on the

proposed penalty.

EPA is authorized under section

311(b)(6) of the Clean Water Act, 33

U.S.C. 1321(b)(6), to assess a civil

penalty after providing the person

subject to the penalty notice of the

proposed penalty and the opportunity

for a hearing, and after providing

interested persons public notice of the

proposed penalty and a reasonable

opportunity to comment on its issuance.

Under section 311(b)(6), any owner,

operator, or person in charge of a vessel,

onshore facility, or offshore facility in

violation of the regulations issued under

section 311(j) of the Clean Water Act, 33

U.S.C. 1321(j), (‘‘Oil Pollution

Prevention Regulations’’—40 CFR part

112) may be assessed a civil penalty of

up to $137,500 by EPA in a ‘‘Class II’’

administrative penalty proceeding.

Class II proceedings under section

311(b)(6) of the Clean Water Act are