HeinOnline -- 64 Fed. Reg. 60194 1999 

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

III. Whatis the Agency Authority for TakingThis Action?

Section 6(f)(1) ofFIFRA provides that

a registrant ofa pesticide product may at any time request that any ofits pesticide registrations be amended to delete one or more uses. The Act further provides that. before acting on the request. EPA mustpublish a notice of receipt ofany 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 writingto James A. Hollins. at the address given above. postmarked May 2. 2000.



### V. Provisions for Disposition ofExisting 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 ofthe revision. unless otherrestrictions have been imposed. as in special review actions.

ListofSubjects

Environmental protection.

Dated: October4.1999.

Richard D. Schmitt,

ActingDirector, Information Resources & ServicesDivision.
[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 NoticeofAdministrative Settlement

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice; request for public
comment.

SUMMARY: In accordance with section 122(i) ofthe Comprehensive Environmental Response. Compensation. and Liability Act. as amended ("CERCLA"). 42 U.S.C. 9622(i). notice is hereby given ofa proposed administrative settlement for
recovery ofpast response costs concerningthe Sanders Aviation Superfund Site in Tempe. Arizona with the Alfred P. Sanders Trust ("Trust") and the trustees ofthe Trust. Pursuant
to the Agreement. the Trust will arrange for the sale ofthe Trustproperty. Seventy-five percent ofthe proceeds of the sale will be paid to the Hazardous Substance Superfund and twenty-five percent willbe paid to the Trust. This allocation is a close approximation of the costs each party has contributed to cleaningup the site. The settlement includes a covenant not to sue the settlingparties pursuant to Sections 106 and 107(a) ofCERCLA. 42 U.S.C. 9606. 9607(a). For thirty (30) days following the date ofpublication ofthis 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 ifcomments received disclose facts or considerations which indicate that the settlement is inappropriate. improper. or inadequate.

The United States' response to any comments received willbe available for public inspection at the U.S. Environmental Protection Agency. 75 Hawthorne Street. San Francisco. CA 94105.

DATES: Comments must be submitted on

orbefore December 6. 1999.

ADDRESSES: Comments should reference the Sanders Aviation Removal Site. Tempe. Arizona and EPA DocketNo. 99-06 and should be addressed to Kara Christenson. Office ofRegional 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 ofthe proposed settlement may be obtained from Kara Christenson. Office ofRegional 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 ofRegional Counsel U.S. Environmental Protection Agency. 75 Hawthorne Street. San Francisco. CA 94105. telephone: (415) 744-1330.

Dated: October 25,1999.
Michael Feeley, DeputyDirector, SupeifundDivision, 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] 

### Categoryfor 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 decisionalprecedents and have streamlined the process for Agency review ofand regulatory follow-up on

new chemical substances. Consistent with TSCA section 26(c). which allows EPA action under TSCA with respect to categories ofchemical substances or mixtures. EPA is issuingthis 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 ofPollution 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) (FRL5571-6). EPA published a Federal Register notice solicitingcomments 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 controlHeinOnline -- 64 Fed. Reg. 60195 1999 

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

## 60195

number for this document is OPPTS53171A.

Category

Chemical manufacturers or importers

This listingis not intended to be exhaustive, butratherprovides a guide for readers regarding entities likely to be affected by this document. Other types ofentities 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 yourbusiness is affected by this document, you should carefully examine the applicability provisions in 40 CFR720.22. Ifyou have any questions regarding the applicability of this document to a particular entity, consult the technical person listed in the "FORFURTHERINFORMATION CONTACT" section.



### B. How Can I GetAdditional Information, Including Copies ofThis Document and OtherRelated Documents?

l. 

### Electronically. You may obtain copies ofthis 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 ofPollution 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 ofthe documents specifically I. 

### General Information

A. Does This DocumentApply to Me?

You may be potentially affected by this document ifyou are or may in the

NAICS Code SIC Codes

325,32411 28,2911

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 officialrecord does not include any information claimed as CBL The public version ofthe officialrecord, which includes printed, paper versions ofany 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, excludinglegal holidays. The telephone number ofthe Center is 202-260-7099.



### 3. Byphone. Ifyou need additional information about this document, you may also contact the person identified in the "FORFURTHERINFORMATION CONTACT" section.



### II. Background

A. Overview ofthe PMN Process
Under section 5(a) ofTSCA, 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) ofTSCA, is any chemical substance (as defined by section 3(2))that is not included on the Inventory compiled under section 8(b) ofTSCA.

Section 5 ofTSCA 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 future be a submitter ofa PMN under TSCA. Potentially affected entities may include, but are not limited to the following:

Examples of Potentially Affected Entities

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 PST criteria described here may be subject to regulatory controls under TSCA section 5(e).

also be suspended voluntarily by the mutual consent ofEPA and the PMN submitter. Duringthe 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 ofnew chemical substances that raise health or environmental concerns. IfEPA 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 mustprovide EPA with a notice ofcommencement 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 involvingthe 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 ofa chemical substance as a "significant new use." Section 5(a)(I)(B) ofTSCA would then require persons to submit a Significant New Use Notice (SNUN) to EPA at least 90 days before they manufacture, import, orprocess the substance for the

use designated as significant. The required SNUN provides EPA with the opportunity to evaluate the intended
use, and ifnecessary, 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. Duringthe interveningyears, EPA has implemented various initiatives which have enabled the Agency to review a greater number ofnew chemicals moreHeinOnline -- 64 Fed. Reg. 60196 1999 

## 60196 Federal Register/Vol. 64, No. 213/Thursday, November 4, 1999/Notices

efficiently. In 1988, for example, EPA's Office ofToxic Substances (now the Office ofPollution 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, includingthe 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 ofnew chemical substances.

PBT chemical substances possess characteristics ofpersistence (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 ofPBT chemical substances include the insecticide DDT and polychlorinated biphenyls (PCBs).

Establishment ofa PBT category alerts potential PMN submitters to possible
assessment orregulatory issues associated with PBT new chemicals review. It also provides a vehicle by which the Agency may gauge the flow ofPBT chemical substances through the TSCA New Chemicals Program and

measure the results ofits 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 ofOctober 5,1998 (63 FR 53417), development ofthe 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 ofpersistent organic pollutants (POPs). The proposed TSCA PBT category has been provided
to the Criteria Expert Group (CEG) established at the first session ofthe Intergovernmental Negotiating Committee (INC) for an International Legally BindingInstrument for ImplementingInternational Action on Certain Persistent Organic Pollutants, in accordance with the mandate given by the Governing Council ofthe United Nations Environment Programme (UNEP) in paragraph 9 ofits decision 19/13 C (http://irptc.unep.ch/pops/ gcpops_e.html). The CEGis an openended technical working group with a mandate to present to the INCproposals for science-based criteria and a procedure for identifying additional POPs as candidates for future international action. The CEGis to incorporate criteria pertainingto 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 CEGrecommended that the INC considerdeveloping a provision encouragingcountries and regions to include in their new chemicals schemes elements relating to development and introduction ofnew chemical POPs. The U.S. described its proposed TSCA new chemicals program policy for the category ofPBT new chemicals, and the full text ofthe 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 ofthe INC (January 25-29, 1999 in Nairobi) and the INC will consider it further in its deliberations.

This policy statement is important in

ournew chemical assessment and TSCA regulatory programs, and represents the first formal statement ofnational policy regarding new chemical "persistent organic pollutants." Under our domestic program, the policy statementprovides guidance criteria for persistence, bioaccumulation, and toxicity for new chemicals and advises the industry about ourregulatory approach for chemicals meetingthe criteria. Internationally, the 

### Federal Register notice ofOctober 5,1998 (63 FR 53417) alerted the parties involved in negotiation ofthe POPs Convention to the need for inclusion ofa new chemicals provision in the Convention. The issuance ofthe 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 ofPOPs as

new chemicals and pesticides.



### III. Discussion ofFinal Policy Statementand Response to Comments

Today's policy statement adopts the criteria and testing strategy ofthe 

### Federal Register notice ofOctober5, 1998 (63 FR53417), with minor revisions. The Agency reviewed and considered all comments received on the October 5, 1998 (63 FR53417) notice. A complete copy ofall
comments received is available in the public docket for this document. A discussion ofthe policy statement, including a summary ofsignificant comments and the Agency's response follows:

A. Pigments
Comment I-Pigments. Commenters suggested that EPA not identify pigments as bioaccumulators and were concerned that testing could end up beingexpensive for pigments, which are persistent by design.

Response. EPA assesses PMN chemical substances for PBT attributes

on a chemical-by-chemical basis, regardless ofwhether or not they fall into a chemical use category such as pigments. Not all pigments are the same and a precise definition ofthe 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 ofdyes orpigments 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 "persistentby design" by itselfis not a sufficientbasis 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 ofconcern, whether or not they are persistent by design. Ifa PMN chemical is persistentby design, and becomes

subject to testingrequirements 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
Comment2-Ready biodegradability testing. Commenters suggested that EPA avoid the use ofstrictpass/fail criteria for ready biodegradability ofpoorly 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. ofthis document), the Agency recognizes the limitations in applying such criteriaHeinOnline -- 64 Fed. Reg. 60197 1999 

### 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 ofcritical aspects beyond the pass/fail result will be considered when evaluatingpotential 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 ofbranching) and bioavailability (e.g., uptake ofa substance by fish or microorganisms), and their influence on both biodegradation and bioaccumulation.

C. Bioconcentration Factorand Kow

Comment 

### 3-Bioconcentrationfactor. Commenters requested clarification on how bioconcentration factor (BCF) will be estimated using calculations based

on octanol-waterpartition coefficient.

Response. The octanol-waterpartition coefficient (Kow) is correlated with the potential for a chemical to bioaccumulate in organisms; the BCF

can be predicted from log Kow, via computerprograms based on structure activity relationship (SAR). The Agency process for predictingbioaccumulation factors (BAFs) and BCFs, along with literature references, is described in

some detail in the proposed rule for lowering ofreportingthresholds for certain PBT toxic chemicals subject to reportingunder section 313 (Toxic Release Inventory, orTRI) ofthe Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986 (January 5,1999 (64 FR 688) (FRL6032-3), see page 704).

Comment4-LogKow and low solubility chemicals. Commenters suggested that the October 5,1998 (63 FR53417) 

### Federal Register notice identified methods for calculatinglog 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 FR53417) 

### Federal Register notice for experimental measurement ofthe octanollwater partition coefficient (Kow), or SARto predict Kow, are appropriate, and the results ofeither 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 oflow solubility in octanol or water alone. The
test guidelines (OPPTS 830.7570 or 830.7560) cited in the October 5,1998 (63 FR53417)

### Federal Register notice

are viewed as the most appropriate for measuring Kow, and alternatively, the shake-flask method (OPPTS 830.7550 test guideline) orthe new "slow-stir" method currently under development by the OECD, can be used. However, ifthe 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 ofa particular PMN chemical substance, a company might forgo a lower tier acute Daphnia toxicity study in favor ofthe chronic study because it would yield the best information for the screening levelrisk assessment.

Comment5-Use ofoctanol solubility data alone. Commenters wanted to know ifoctanol 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 ofpotential 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 ofchemicals between water and fat, and
cannot be accurately estimated via separate determinations ofsolubility in pure octanol and water (i.e., by calculatingthe ratio ofthe pure-solvent solubilities) (Sijm et aI., 1999, see Unit VI.l.). The Agency uses and recommends the use ofcomputer models to predict Kow where there are

no measured data.

D. Environmental Half-Life

Comment6-Calculation ofhalf-life. Commenters wanted to know how halflife is calculated in the review ofPBT

new chemicals.

Response. Multimedia fate models like the Environmental Quality Criteria (EQc) model (Mackay et aI., 1996, see Unit VI.2.) require compartmentalhalflives 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

orAOPWIN) or similar methodology. Studies by Boethlinget 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 waterhalf-life is to

use the Ultimate Survey Model (USM) in the EPI BIOWIN program (Boethling
et aI., 1994, see Unit VI.5.). Estimation ofbulk compartmenthalf-lives from USM model data requires several assumptions, includingthat (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 waterhalf-life.

E. ComputerModels and the Use of Models vs. A ctualData
Comment 7-Use ofmodels vs. actual data. Commenters support the use ofthe Mackay/EQCmodel, but stressed the importance ofhaving a process for using
actual data in place ofthe model.

Response. This is a reasonable suggestion. The EQC model is based on the fugacity approach and subsequently applied to numerous environmental processes. Ituses an "evaluative environment" in which environmental parameters such as bulk compartment dimensions and volumes (e.g., total
area, volume ofsoil and sediment, etc.)

are standardized, so that overall persistence for chemicals with different properties and rates oftransformation
may be compared on an equalbasis. In general, measured values oftoxicity, chemicalproperties, compartmental transformation half-lives, etc., provided the data are ofacceptable quality, are preferred over those that are predicted

or estimated via a model or computer program.

Comment 8-Modeling ofair releases. Commenters noted that the October5, 1998 (63 FR53417)

### Federal Register notice considered only biodegradation and aqueous hydrolysis and asked about fate ofa 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 evaluatingthe 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 (ofwhich 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 importantHeinOnline -- 64 Fed. Reg. 60198 1999 

## 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 ofmany PMN substances as well. It is through multimedia fate models such as EQC that atmospheric fate willbe considered in developing an overallprediction 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 ofatmospheric half-lives.

F. 

### Use of"Weight ofEvidence"and ProfessionalJudgment

Comment 9-Laboratory vs.field behaviorofchemicals. Commenters indicated thatEPA needs to incorporate any differences between lab and field behavior ofchemicals into its analysis ofnew chemical substances, acknowledge the limitations of screening-levelbiodegradation tests, and acknowledge the value ofusing professionaljudgment when interpretingdata from extended (> 60 day) degradation studies.



### Response. EPA recognizes that laboratory tests at best provide a snapshot ofexpected 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 extrapolatingfrom lab to field. EPA similarly acknowledges the limitations ofready biodegradability and other screeningtests as indicators of ultimate environmental behavior. Finally, it is wellknown 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 I0- 

### "Check the box"vs. "weight ofevidence." 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 professionaljudgment 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 oftest data) and professionaljudgment,EPA leans towards a "reasonable worst case" when there is lack ofchemical-specific data. Industry always has the option of assisting and enhancingthe Agency's determinations by submitting scientifically valid test data. There are a number ofexisting documents describing the PMN process and the critical role played by SAR and professionaljudgment in that process, includingthe Chemistry Assistance Manual for Premanufacture Notification Submitters (USEPA, 1997, see Unit VI.6.) and parts ofthe report on thejoint U.S.lEuropean Union study that evaluated the predictive power ofthe SAR (USEPA, 1994, see Unit VI.7.). EPA believes that, where no orinsufficient actual toxicity data exist upon which to base a decision, toxicity estimates generated by SARs and otherpredictive 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 ofDecember 1, 1993 (58 FR 63507) for a similar
statement related to meeting section 313 listing criteria underEPCRA of 1986).



### Comment II-Implement PBTpolicy within risk assessmentframework. Commenters suggested that EPA risk management decisions should notbe 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 Band T before requiring further testing oridentifying 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 exposurelrelease substances from consideration under this category and were concerned that the current proposed criteria do not consider any health and safety benefits ofa 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 ofpotential health and environmental effects ifEPA determines either (1) that the manufacture (includingimport), processing, distribution in commerce, use, or disposal ofthe substance may present an unreasonable risk ofinjury 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 ofthe 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 Band T, individually and together, and
exposure in makingrisk-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 ofthe potential hazard ofthe substance and the expected exposure. In other instances,

as discussed in the October 5, 1998 (63 FR53417)

### 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 significantor substantial human exposure to the substance," and that the available information is insufficient to determine the effects ofthe 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 ofproduction or exposurelrelease than

are described in the general guidelines for the new chemicals program'sHeinOnline -- 64 Fed. Reg. 60199 1999 

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

## 60199

exposure-based policy (USEPA, 1988, USEPA, 1989, see Unit VL8. and 9.). Overall, companies are not being prevented from developing and using

new substances that arejudged to be potential PBT chemicals, but EPA may require certain controls (e.g., limiting the release ofthe PMN chemical to the environment) or testing as a result ofits
assessments.

In order to be so identified as a PBT

new chemicalbased on a risk-based finding, all three criteria must be satisfied. The Agency has adopted a 1 to 3 rating system for each ofP, B, and T. Ifchemical 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 ofthe PBT criteria, ifthey otherwise meet the risk or exposurebased elements ofTSCA 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 ofmore persistent materials, the environmental "desirability" ofa given chemical often depends on a balance ofvarious factors, includingtoxicity and ability ofthe 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 ofthis is chronic toxicity towards aquatic organisms of organotins from contaminated marine environments, which ultimately resulted in the regulation ofuse 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. 

### Scientificjustificationfor PBT Technical Criteria

Comment 12-Supportforlower threshold criteriafor "P"and "B." Commenters believed that there is little precedent, scientificjustification, evidence or data to support the lower regulatory threshold ofbioaccumulation factor of 1,000 and environmental persistence of2 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 of2 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 recentproposal to lower the reporting thresholds for PBT chemicals that are subject to reportingunder section 313 ofEPCRA (64 FR 688; January 5,1999), similar values have been proposed by several authorities, includingthe Ontario, Canada Ministry ofEnvironment and Energy (MOEE) for its Candidate Substances List for Bans

orPhaseouts (MOEE, 1992, see Unit VI.lO.); the Canadian initiative for Accelerated Reduction/Elimination of Toxics (ARET) (ARET, 1995 and ARET, 1994, see Unit VI.ll. and 12.); the International Joint Commission (IJC)'s Great Lakes Water Quality Agreement (GLWQA) (IJC, 1993, see Unit VI.l3.); 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 ofrecord for water (UNECELRTAP, 1998, see Unit VI.l4.).

In determining the thresholds for this policy statement, EPA concluded that it would be appropriate to reflect the levels ofconcern 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' varyingpotentials to persist and bioaccumulate, as well as to reflect the Agency's beliefthat the different levels ofregulatory 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 orbioaccumulation 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/BCFvalues of 1,000 and 5,000. The preamble to the EPCRA proposed rule states "Bearingin mind that one ofCongress' 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 of2 months for water, sediment, and soil, and 2 days in air, and for bioaccumulation, bioaccum ulation/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 ofEPA'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 ofa PMN chemical substance due to lack ofdata, the TSCA

new chemicals program is and mustbe 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 ILB. ofthis document, developed indicative numerical values as bracketed criteria
text which included persistence of2 vs. 6 months in water and log Kow of4 vs. 5 (equivalent to a BCF ofapproximately 1,000 vs. 5,000, respectively).

A series ofPMNs submitted to EPA in 1990 (Zeeman et aI., 1999, see Unit VI.l5.) 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, andHeinOnline -- 64 Fed. Reg. 60200 1999 

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biodegradability. The submitted environmental fate data and EPA estimates ofbiodegradability 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 ofconcerns 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 ofEPA's beliefthat a potential for long-term risk existed, but that EPA could not quantify this risk since

assessments typically evaluated releases

over a period ofonly 1 year. In 1998, results ofmonitoringrevealed 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 informingthe PMN submitter ofthe potential for long-term risk, the Agency would likely have required further testing to obtain an experimental value for environmental persistence ofthe chemicals. This in turn would have given the Agency a betterpicture ofthe behavior ofthe chemicals in the environment and the environmental half-life relative to the 2 month value.



### Comment I3-Deny commercialization
to lowerthreshold PBTchemicals. Some

commenters supported exercisingthe "Precautionary Principle" by not allowing commercialization under a TSCA 5(e) consent order or SNUR pendingtesting ofthe PMN chemicals which meet the P=2 month and BCF=l,OOO criteria. They suggested that these chemicals should be banned instead, pendingthe necessary testing.



### Response. Whereas a half-life of2 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 pendingtesting" at these cutoffs given the uncertainties about substance properties, release, and environmental behavior that normally characterize PMNreview. The Agency believes that the available predictive tools and current knowledge ofPOPs lend support for this two-phased approach to screening ofPBT chemicals and collection ofinformation "sufficient
to permit a reasoned evaluation of potential health and environmental effects" ifEPA makes the requisite riskor exposure-based findings under TSCA section 5(e).



### Comment I4-Relationship of P, B, and T criteria. Commenters suggested that the October 5, 1998 (63 FR53417) 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 oflong-term toxicity.



### Response. The statement in question

was intended simply to note that the 2 months half-life in waterpersistence criterion closely tracks the duration of long-term environmental toxicity or bioaccumulation tests. Ifa 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 identifyingPOPs warranting international action (e.g., in programs like UNECE-LRTAP and UNEP Global Negotiations on POPs)have notbeen selected based on the duration of toxicity orbioaccumulation tests. There

are no cutoffs or "fence lines" for environmental persistence criteria that emerge as immutable quantities solely from scientific analysis; the choice of screeningcriteria is a policy decision guided by the anticipated scope ofa negotiation orregulatory activity. In the

case ofthe PMN program, 2 months represents a reasonable screeninglevel value for "persistence" which is more than the I-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 ofPOPs in the Great Lakes Basin, UNECE-LRTAP, North American Free Trade Agreement Commission for Environmental Cooperation (NAFTACEC), etc.) as reflecting the persistence ofknown POPs chemicals (e.g., DDT, hexachlorobenzene). As mentioned in the previous response, there is international support, through the CEG, for persistence values of2 or 6 months in water.



### Comment IS-Relationship ofPand B. Commenters suggested that the October 5,1998 (63 FR 53417) notice's
statement, "Generally, persistent bioaccumulators are chemical substances thatpartition 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 ofpersistence 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 ofthe PBT concern level for PMN chemical substances.



### H. Relationship ofTSCA PBTPolicy to OtherAgency and International PBT Initiatives

Comment I6-Finalize overallAgency

multimedia strategyfirst. Commenters suggested that the PBT classification criteria beingproposed 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 ofvoluntary waste minimization efforts
to reduce the generation ofthose PBT chemicals which are found in hazardous
waste regulated under the Resource Conservation and Recovery Act (RCRA) (63 FR 60332; November 9,1998 (FRL6186-7)), (2) the Agency draft Multimedia PBT Strategy (63 FR 63926; November 17, 1998 (FRL-6045-2)), and (3) the lowering ofreporting thresholds for certain PBT toxic chemicals subject
to reportingunder section 313 (Toxic Release Inventory, or TRI) ofEPCRA of 1986 (64 FR 688; January 5, 1999). These commenters stated that the TSCA notice is premature, occurringbefore adoption ofthe overall Agency strategy, and is inconsistent with other initiatives, domestic and international, which have lists ofchemicals 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 ofthe Agency strategy.



### Response. The PBT Multimedia Strategy formalizes an Agency process for integration ofprogram activities involving these types ofsubstances. While the strategy intends to coordinate Agency PBT-related activities under itsHeinOnline -- 64 Fed. Reg. 60201 1999 

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## 60201

framework, the strategy does not establish rigid criteria with respect to PBTs. Program offices must operate within the parameters oftheir 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 ofnew chemicals, and the opportunity to protect against unreasonable risks, ifany. The structure ofthat 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 ofaddressingpotential concerns for substances possessingPBT characteristics. It is EPA's intention that the strategy be a living document. Therefore, the strategy willbe updated based upon public comment; it will not be "finalized" in the more traditional

sense ofa rulemaking. EPA does agree that consistency is a laudable goal where the criteria are meant to be used for similarpurposes and is seriously consideringcomments within the

context ofthe strategy regarding establishment ofconsistent criteria for priority PBTs.

Comment I7-CareJully communicate lowerthresholds. Commenters suggested that EPA should use only the environmental persistence of6 months/ BCF of5,000 screeninglevels for consistency amongEPA 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 of2 month/BCF of 1,000 is appropriate for risk screening activities under TSCA. Communication is occurringin the international forum. Unit ILB. ofthis document discusses the CEGfor 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 ofnew chemical POPs. The U.s. described its proposed TSCA new chemicals program policy for the category ofPBT new chemicals, and the full text ofthe 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 ofthe INC (January 25- 29, 1999 in Nairobi) and the INC will consider it further in its deliberations.

1. Testing Strategy

Comment I8-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 whatresults willbe considered acceptable by the Agency.

Response. Each ofP and Band Tare 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 ofpersistence 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 ofthe critical role these aspects play in PBT determinations and because oftheir 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, ifany, orby analogy to structurally similar chemicals. Ifa company knows

or suspects prior to testing that their chemical is likely to be persistent and bioaccumulative, consideration should be given to conductingchronic 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 VL8. and 9.), the standard screeninglevel 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 I9-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 ofdifferent but acceptable means to providingtesting information. However, EPA's acceptance ofa guideline not specified in this policy statement and/or use of data generated under such guidelines depends on multiple factors including the specifics ofthe test substance, purpose ofthe testing, familiarity with specific procedures and equipment, validation ofthe method, etc. Typical TSCA 5(e) consent orders require that testingperformed pursuant to the order
must be conducted according to TSCA Good Laboratory Practice Standards at 40 CFRpart 792 and using methodologies generally accepted at the time the study is initiated. Before startingto 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. ofthis document)provide general guidance for development oftest protocols, butare not themselves acceptable protocols.

1 Applicability ojPBT Criteria to Metals

Comment20-PBTcriteria are not appropriateJormetals. 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 identifyingpotential PBTs, on the one hand, and on the other: (1) the means of generatinginformation on the P, B, and T endpoints for comparison to the criteria, and (2) the applicability of existingtest guidelines for generating such information experimentally.

EPA understands that metals are intrinsically not degradable in the sense ofultimate degradation oforganics (although they may undergo biologically

as well as chemically induced changes in, e.g., oxidation state), and therefore

are persistentby definition, but nevertheless may not be bioaccumulative. Itis widely accepted that elemental metals are persistent by definition, since they may take differentHeinOnline -- 64 Fed. Reg. 60202 1999 

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forms that can be interconverted, but the elemental metal itselfcannot 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 oftest guidelines, the same level ofjudgment 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 thatbioavailability 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 ofthe proposed criteria for identifyingpersistent, 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 commentsiresponses in this policy
statement) or any other specific classes oforganics. What is necessary is to consider what is known about the behavior ofsubstances like metals during the TSCA PMNreview process, both in the assessment ofwhether a given chemical substance meets the established criteria and in subsequent testing decisions. For any untested PMN chemical substance, ifthere are no close analogs with data and no clearevidence 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 isjudged sufficiently persistent and
meets the criteria for bioaccumulation potential and toxicity is ofconcern for "PBTness" regardless oftheoretical 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 professionaljudgmentin considering issues like bioavailability ofmetals. Using lead as an example, many processes commonly observed in the environment can result in the presence ofbioavailable (ionic) lead where it can be bioaccumulated by organisms. These
processes may occur in soil and aquatic environments with low pH and low levels oforganic matter. Under these conditions, the solubility oflead is enhanced and, in the absence ofsorbing surfaces and colloids, lead ion can remain in solution for a sufficient period to be taken up by biota. Lead sorption to soil organic matterhas been shown to be pH dependent. Decreasing pH can lead to increasing concentrations oflead in soil and water. Microbial transformations in soil, water, and sediment are also important in determining the overall fate ofmetals and metal compounds, and therefore the potential for formation ofbioavailable forms. Metals are generally taken into cells by nutrient metal transport systems, and these are not sufficiently specific to completely exclude nonessential metals, some ofwhich may be toxic and/orbioaccumulative. In this situation, nutrient metals can be displaced from theirbinding sites by undesirable, toxic metals, which then gain access to the cell interior with concomitant exclusion ofthe essential metal (Stumm and Morgan, 1996 see Unit VI.l6.). 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 ofthe TSCA New Chemicals Program that if the metal in a metal compound cannot become available as a result ofbiotic or abiotic processes then the metal will not be available to express its toxicity, and by extension, to bioaccumulate. Ifthe intact metal compound is not toxic and the metal is not available from the metal compound, then such a chemical would
notbe 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 Processfor New PBT Chemical Substances

EPA is adopting the following specific identification criteria and associated
process for use in evaluatingnew chemical substances.

NEW CHEMICALS PROGRAM PBT CATEGORY CRITERIA AND PROCESS

TSCA Section 5(e) Action
5(e) Order Pending Test- 5(e) Ban ing/Significant Pending New Use Rule Testing2 (SNUR)1

Persistence > 2 months

...... > 6 months

(transformation half-life). Bioaccumu- 21,000

............ 25,000

lation (Fish BCF

or BAF)3. Toxicity

....... Develop toxicity Develop toxdata where icity data necessary4 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 x 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. ofthis document may need to undergo testing on "P" and "B" endpoints which, ifconfirmed, 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 ofrisk concern. Agency control actions taken under TSCA section 5(e)for chemical substances meetingthese criteria would be based upon the level ofcertainty for the PBT properties ofa PMN substance (e.g., measured vs. estimated values), the magnitude ofAgency concerns, and conditions ofexpected use and release ofthe chemical. For example, new chemical substances meetingthe PBT criteria listed under "5(e) Order Pending Testing/SignificantNew Use Rule (SNUR)" could be addressed via a negotiated consent agreementunderHeinOnline -- 64 Fed. Reg. 60203 1999 

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## 60203

which necessary testing is "triggered" by specific production limits. While the PMN submitterwould be allowed to commercialize the substance, certain controls could be stipulated, including annual TRI-type reporting on

environmental releases ofthe PMN substance and specific limits on exposures, releases, oruses. The "ban pendingtesting" criteria are equivalent
to those that have been used internationally to identify POPs. For the chemical substances meetingthese criteria, the concern level is higher and the Agency would look carefully at any and all environmental releases. Because ofthe 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 ofrisk can be appropriately addressed by less restrictive measures. The control actions described in the table in Unit IV.A. of this document representjust one body ofpossible decisions and should not be considered as exclusive ofotherrisk management options.

B. Testing Strategyfor PBT Chernical Substances

Where EPA is unable to adequately determine the potential for bioaccumulation, persistence in the environment, and toxicity which may result from exposure ofhumans and environmental organisms to a possible PBT chemical substance, the Agency may conclude, pursuant to sections 5(e)(l)(A)(i) and 5(e)(1)(A)(ii)(I) and (II) ofTSCA, that the information available
to the Agency is insufficient to permit

a reasoned evaluation ofthe human health and environmental effects ofthat PMN substance, that the manufacturing, processing, distribution in commerce, use, or disposal ofthe substance may present an unreasonable risk ofinjury to human health or the environment, and/

orthat the PMN substance will be produced in substantial quantities and that there may be significant or substantialhuman exposure to the substance orthe 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 ofthe PMN substance in the United States pendingthe development ofinformation necessary for a reasoned evaluation ofthese effects. The following testing strategy describes test data which EPA believes

are needed to evaluate the persistence, bioaccumulation, and toxicity ofa PBT chemical substance for which EPA has made the above described risk and/or exposure-based findings under section 5(e)(l)(A)(i) and (ii) ofTSCA. The tests

are tiered; dependingupon the circumstances, such as magnitude of environmental releases, results of testing, or SAR, testing could begin above Tier 1 or additional, higher levels oftesting may be required. As discussed in the response to Comment 19 in Unit IILL ofthis 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 startingto conduct
any such study under the terms ofa Consent Orderunder TSCA section 5(e), the PMN submitter must obtain approval oftest protocols from EPA by submitting written protocols. Published
test guidelines specified in Unit IV.B. of this document provide general guidance for development oftest protocols, but

are not themselves acceptable protocols.

Tier 1. If, based upon available test data, SAR, and professionaljudgment, 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:

l. Ready biodegradability (OPPTS 835.3110 test guideline) 6 methods (choose one): DOC Die-Away, CO2 Evolution, Modified MIT! (I), Closed Bottle, Modified OECD Screening, Manometric Respirometry.

2. Sealed-vessel CO2 production test (OPPTS 835.3120 test guideline).

Ifthe measured log Kow is 

### < 4.2 (equivalent to an estimated BCF of 1,000)or ifthe test chemical passes (pass criteria are described in the test guidelines) the ready biodegradability
test (i.e., notpersistent in the environment), no further PBT-related testingis required. Ifthe 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. Ifhydrolysis testingis conducted and results in a half-life of

### < 60 days, further testing may notbe needed, but the need for testing must be determined after consideration offactors specific to the case, such as physical/ chemicalproperties, persistence and bioaccumulative qualities ofhydrolysis products, and the nature ofthe expected releases.

Tier2. Biodegradability should be determined according to the Shake-flask die-away test (OPPTS 835.3170 test guideline). This test is based on the principle ofaerobic incubation ofthe
test chemical in natural water with and without suspended sediment, requires a chemical-specific analytical method, and allows for the development ofa 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 ofthe bioconcentration factor (BCF), using the Fish bioconcentration test (OPPTS 850.1730
test guideline (public draft)). Measured BCF should be based on 100percent active ingredient and measured

concentration(s).

Ifthe measured biodegradation halflife is 

### > 60 days and measured BCF is



### > 1,000, tier 3 testing will normally be required. Ifonly one condition is met, releases and exposure are further considered to determine ifadditional testingis required.

Tier3. Toxicity/advanced environmental fate testing. Human health hazards should be determined in the combined repeated dose oral toxicity with the reproductive/ developmental toxicity screeningtest (OECD No. 422 test guideline)in rats. Otherhealth 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 ofthis method is the determination ofthe test chemical's fate, includingtransport and transformation, in core chambers containingintact 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.,HeinOnline -- 64 Fed. Reg. 60204 1999 

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endocrine disruptingpotential)willbe considered where appropriate.

V. Intended Legal Affect ofthis Policy Statement

The policy discussed in this document provides general guidance on the Agency's use ofa category grouping for PBT new chemical substances to facilitate the PMN assessment process for PMN submitters and EPA reviewers. EPA uses groupings ofnew 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 ofand 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 itbe relied upon. to create any rights enforceable by any party in litigation with the United States. Although this guidance provides a startingpoint 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 ifchanges

are necessary at some point in the future. the Agency may revise. clarify.

orupdate the text ofthis guidance withoutpublic 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. Evaluatingthe environmental fate ofa variety oftypes ofchemicals usingthe EQC model. 

### Environ. Toxicol. Chem. 15:1627-1637.

3. BoethlingRS. PH Howard. JA Beauman and MELarosche. 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 C02 screeningtest to activated sludge. river
water. and soil. 

### Environ. Toxicol. Chem. 16: 127-134.

5. BoethlingRS. Howard PH. Meylan W. StitelerW. Beauman J. Tirado N. 1994. Group contribution method for predictingprobability and rate of aerobic biodegradation. 

### Environ. Sci. 

### Technol. 28: 459-465.

6. USEPA. March. 1997. Chemistry Assistance Manual for Premanufacture Notification Submitters. EPA 744-R97-003. 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 ofEnvironment 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 ofToxics (ARET) Secretariat. 1995. Environment leaders 1. Voluntary commitments to action on toxics through ARET. March 95. 12. Accelerated Reduction/ Elimination ofToxics (ARET) Secretariat. 1994. The ARET substance selection process and guidelines. January 94. 13. International Joint Commission (IJC). 1993. A strategy for the virtual elimination ofpersistent toxic substances. Vol. 1. report ofthe Virtual Elimination TaskForce 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 negotiatingtext for a protocol

on persistent organic pollutants. UNECE. EB.AIRl1998/2. 31 March 1998. 15. Zeeman. M.• D Rodier. and N Nabholz. 1999. Chapter 2. Ecological Risks ofa New Industrial Chemical. Under TSCA. In Ecological Risk Assessment in the Federal Government (Executive Office ofthe President. National Science and Technology Council. Committee on Environment and Natural Resources. Ed.). CENRl5- 99/001. May. 1999.pp 2-1 to 2-30. 16. Stumm. W. and JJMorgan. 1996. 

### Aquatic Chemistry. 3rd ed. New York: Wiley.

List ofSubjects

Environmental protection. Chemical substances. Hazardous substances. Reporting and recordkeeping
requirements.

Dated: October 22.1999.

Susan H. Wayland,
DeputyAssistantAdministratorfor Prevention, Pesticidesand Toxic Substances.
[FR Doc. 99-28888 Filed 11-3-99; 8:45 am]

BILLING CODE 6560-50-F



### ENVIRONMENTAL PROTECTION AGENCY
[FRL--6469--6]



### Noticeof Proposed Assessment of Clean Water Act Class II Administrative Penalty and Opportunity To Comment

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.

SUMMARY: EPA is providingnotice ofa proposed administrative penalty for alleged violations ofthe Clean Water Act. EPA is also providingnotice of opportunity to comment on the proposed penalty.

EPA is authorized under section 3ll(b)(6) ofthe Clean Water Act. 33 U.S.C. l32l(b)(6). to assess a civil penalty after providingthe person subject to the penalty notice ofthe proposed penalty and the opportunity for a hearing. and after providing interested persons public notice ofthe proposed penalty and a reasonable opportunity to comment on its issuance. Under section 311(b)(6). any owner. operator. orperson in charge ofa vessel. onshore facility. or offshore facility in violation ofthe regulations issued under section 311U) ofthe Clean Water Act. 33 U.S.C. l32lU). ("Oil Pollution Prevention Regulations"--40 CFRpart 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 3ll(b)(6) ofthe Clean Water Act are