Revocation of Final Multi-substance Rule for the Testing of Neurotoxicity

SUMMARY: This document announces EPA's decision to revoke the Multi-

Substance Rule for the Testing of Neurotoxicity, that required

manufacturers and processors of acetone (CAS No. 67-64-1), technical

grade n-amyl acetate (CAS No. 628-63-7), 1-butanol (CAS No. 71-36-3),

n-butyl acetate (CAS No. 123-86-4), diethyl ether (CAS No. 60-29-7), 2-

ethoxyethanol (CAS No. 110-80-5), ethyl acetate (CAS No. 141-78-6),

isobutyl alcohol (CAS No. 78-83-1), methyl isobutyl ketone (CAS No.

108-10-1), and tetrahydrofuran (CAS No. 109-99-9) to conduct testing

for neurotoxicity. EPA is revoking this rule as part of a settlement

agreement reached with the manufacturers of these chemicals, who have

agreed to perform certain neurotoxicity and in vivo hydrolysis testing

of 7 of the 10 chemicals under enforceable consent agreements

(``ECAs'').

EFFECTIVE DATE: January 23, 1995.

ADDRESSES: A public version of the administrative record supporting

this action, with any confidential business information deleted, is

available for inspection at the TSCA Nonconfidential Information

Center, also known as the TSCA Public Docket Office (7407), Rm. NE

B607, Office of Pollution Prevention and Toxics, Environmental

Protection Agency, 401 M St., SW., Washington, DC 20460 from 12 noon to

4:00 p.m. Monday through Friday, except legal holidays.

FOR FURTHER INFORMATION CONTACT: Susan Hazen, Director, Environmental

Assistance Division, (7408), Office of Pollution Prevention and Toxics,

401 M St., SW., Washington, DC 20460, (202) 554-1404, TDD (202) 554-

0551.

SUPPLEMENTARY INFORMATION: EPA has determined that it is appropriate to

revoke the multi-substance rule for the testing of neurotoxicity

because the manufacturers of 7 of the 10 chemicals subject to the final

test rule have agreed to conduct a modified set of neurotoxicity and in

vivo hydrolysis testing under ECAs that accomplish many of the goals of

the test rule. The following seven chemical substances will be tested

pursuant to ECAs: acetone (CAS No. 67-64-1), technical grade n-amyl

acetate (CAS No. 628-63-7), n-butyl acetate (CAS No. 123-86-4), ethyl

acetate (CAS No. 141-78-6), isobutyl alcohol (CAS No. 78-83-1), methyl

isobutyl ketone (CAS No. 108-10-1), and tetrahydrofuran (CAS No. 109-

99-9). Testing is currently underway for n-butyl acetate and isobutyl

alcohol. In vivo hydrolysis testing will be conducted on butyl acetate

to determine if its test results for neurotoxicity can be used to

assess the neurotoxicity of its metabolite, 1-butanol.

I. Background

On July 27, 1993 (58 FR 40262) EPA issued a test rule under TSCA

section 4 that required manufacturers and processors of 10 substances

to conduct testing for neurotoxicity (Ref. 1). The test rule required

all the testing proposed for the 10 substances on March 4, 1991 (56 FR

9105). The required testing was the same for all 10 substances and

included acute and subchronic functional observational battery and

motor activity, and subchronic neuropathology and schedule-controlled

operant behavior (SCOB). These 10 substances are listed below:

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

Chemical name CAS No.

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

acetone............................ 67-64-1

n-amyl acetate, technical grade.... 628-63-7

1-butanol.......................... 71-36-3

n-butyl acetate.................... 123-86-4

diethyl ether...................... 60-29-7

2-ethoxyethanol.................... 110-80-5

ethyl acetate...................... 141-78-6

isobutyl alcohol................... 78-83-1

methyl isobutyl ketone............. 108-10-1

tetrahydrofuran.................... 109-99-9

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

The manufacturers of these substances petitioned for review of the

final rule under TSCA section 19 in the Fifth Circuit Court of Appeals

(Ref. 2). Subsequent to the filing of this challenge to the rule, EPA,

the Chemical Manufacturers Association (``CMA''), and authorized

representatives of all parties challenging the rule, entered into

settlement negotiations to resolve the lawsuit.

As a result of these settlement discussions, the parties to the

lawsuit agreed, subject to certain conditions set forth in the

settlement agreement (Ref. 3), to conduct neurotoxicity and in vivo

hydrolysis testing of 7 chemical substances under ECAs to be negotiated

pursuant to EPA regulations. Testing on two of the chemicals subject to

the final rule, n-butyl acetate and isobutyl alcohol, was already

underway. It was CMA's and the test sponsors stated intent that such

testing continue on schedule during the pendency of this proceeding

(Ref. 3).

In turn, EPA agreed to propose to withdraw the final test rule. EPA

was aware that the settlement agreement contemplated testing fewer

chemicals and a reduced set of testing on some of those chemicals than

the testing regimen required by the final rule. Although EPA believed

that the rulemaking record contained substantial evidence to support

the testing requirements in the final rule, EPA believed that the

settlement agreement was in the public interest as it allowed testing

to proceed on an expedited basis, without the uncertainties of

protracted litigation. CMA's lawsuit was dismissed without prejudice by

the 5th Circuit Court of Appeals on May 13, 1994, in response to a

joint motion for a stay, but it can be reinstated by either party upon

filing of a letter with the court (Ref. 4).

On June 27, 1994, EPA published three notices in the Federal

Register: a Stay of the final test rule (59 FR 33184), a proposal to

revoke the final test rule (59 FR 33187), and an announcement of a

public meeting to initiate negotiation of consent agreement testing (59

FR 33191). The Stay suspended all requirements of the final test rule

until EPA either lifted the Stay or revoked the test rule. Final

revocation of the test rule was conditional on the successful

negotiation of testing to be performed under ECAs. The public meeting

announcement solicited interested parties to participate in the

negotiation and/or observation of negotiations. On July 28, 1994, EPA

held the public meeting to initiate the negotiations. The ECAs which

resulted were signed in November 1994 and January 1995 and required the

neurotoxicity and in vivo hydrolysis testing of the following 7

substances:

[[Page 4515]]

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

Substance Tests

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

acetone.......................... SCOB (subchronic)

n-amyl acetate, technical grade.. Functional Observational Battery

(acute and subchronic), Motor

Activity (acute and subchronic),

Neuropathology (subchronic)

n-butyl acetate.................. Functional Observational Battery

(acute and subchronic), Motor

Activity (acute and subchronic),

Neuropathology (subchronic), SCOB

(subchronic), In Vivo Hydrolysis

ethyl acetate.................... Functional Observational Battery

(acute and subchronic), Motor

Activity (acute and subchronic),

Neuropathology (subchronic), SCOB

(subchronic)

isobutyl alcohol................. Functional Observational Battery

(acute and subchronic), Motor

Activity (acute and subchronic),

Neuropathology (subchronic), SCOB

(subchronic)

methyl isobutyl ketone........... SCOB (subchronic)

tetrahydrofuran.................. Functional Observational Battery

(acute and subchronic), Motor

Activity (acute and subchronic),

Neuropathology (subchronic)

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

The ECA testing program and negotiations are described more fully

in the announcement of the signing of the ECAs, published elsewhere in

this Federal Register. Compared with the final rule, the above testing

program represents a retention of the full set of tests for three

chemicals (n-butyl acetate, ethyl acetate, and isobutyl acetate), a

reduction in tests for four chemicals (acetone, n-amyl acetate, methyl

isobutyl ketone, and tetrahydrofuran), and an elimination of testing

for three chemicals (1-butanol, diethyl ether, and 2-ethoxyethanol). It

is anticipated, however, that the in vivo hydrolysis test of n-butyl

acetate may indicate that the separate testing of 1-butanol may not be

necessary, and because of this, 1-butanol manufacturers have agreed to

share in the cost of n-butyl acetate testing. The evaluation of the

metabolic fate of butyl acetate will be performed in a study of its in

vivo hydrolysis to 1-butanol. If the conversion of butyl acetate to 1-

butanol is sufficiently rapid and complete, EPA may determine that the

neurotoxic effects of 1-butanol can be predicted from the results of

butyl acetate testing. If this is not the case, EPA may consider

reproposing separate testing of 1-butanol.

As mentioned above, a third notice was published on June 27, 1994

(59 FR 33187), which proposed to revoke the final multi-substance rule

for the testing of neurotoxicity. This notice allowed all interested

parties an opportunity to evaluate and comment on EPA's proposed

revocation of the final rule and decision to pursue ECAs as the

mechanism for achieving testing.

II. Public Comments

EPA received one comment on the proposed revocation. This comment

was from CMA and supported EPA's proposal to revoke the test rule and

enter consent agreement negotiations (Ref. 5).

The public meeting to initiate negotiation of consent agreement

testing was held on July 28, 1994. No new interested parties identified

themselves to EPA at this meeting or during the 30-day comment period.

During the meeting, the only comment concerning the proposed revocation

came from CMA's legal counsel, and related to procedures for

simultaneous signing of the ECAs and the revocation.

III. Revocation of Final Test Rule

EPA is revoking the final Multi-Substance Rule for the Testing of

Neurotoxicity (40 CFR 799.5050) based upon the reasons stated in the

proposed revocation (59 FR 33187, June 27, 1994, Unit II), the lack of

comments opposing the revocation, and the successful negotiation of

ECAs. EPA believes the decision to allow manufacturers of these

substances to conduct neurotoxicity and in vivo hydrolysis testing

under ECAs will allow for the most timely development and public

availability of data to assess the potential neurotoxicity of these

compounds. While EPA acknowledges that the testing that will be

conducted under ECAs will not be as extensive as that required by the

final test rule, EPA believes that use of the ECA process will result

in the fastest development of data. Testing and data development will

proceed without the potentially lengthy delay of testing pending

resolution of costly litigation on the merits of the final test rule.

IV. Rulemaking Record

EPA has established a record for this revocation under docket

number OPPTS-42134F. This record contains the following information:

A. Supporting Documentation

(1) Federal Register notices pertaining to this rule consisting of:

(a) Notice of proposed multi-substance rule for the testing of

neurotoxcity (56 FR 9105, March 4, 1991).

(b) Notice of final multi-substance rule for the testing of

neurotoxicity (58 FR 40262, July 27, 1993).

(c) Notice announcing administrative stay of final multi-substance

rule for the testing of neurotoxicity (59 FR 33184, June 27, 1994).

(d) Notice of proposed revocation of final multi-substance rule for

the testing of neurotoxicity (59 FR 33187, June 27, 1994).

(e) Notice announcing opportunity to participate in negotiations

for neurotoxicity testing; solicitation for interested parties (59 FR

33191, June 27, 1994).

(2) Communications consisting of:

(a) Written letters.

(b) Contact reports of telephone conversations.

(c) Meeting summaries (including public meeting on July 28, 1994).

B. References

(1) Final multi-substance rule for the testing of neurotoxicity

(58 FR 40262, July 27, 1993).

(2) Chemical Manufacturers Association (CMA). Petition for

Review. Filed with United States Court of Appeals for the Fifth

Circuit. (October 8, 1993).

(3) United States Court of Appeals for the Fifth Circuit.

Settlement Agreement between Environmental Protection Agency (USEPA)

and petitioners. No. 93-5381. (April 28, 1994).

(4) United States Court of Appeals for the Fifth Circuit.

Dismissal of petitioners appeal against EPA. No.93-5381. (May 13,

1994).

(5) Latham & Watkins (legal counsel to CMA), Washington, DC.

Comment on proposed revocation of final multi-substance rule for the

testing of neurotoxicity. Submitted to TSCA Docket Office, USEPA,

Washington, DC.(July 20, 1994). [[Page 4516]]

The public record for this rulemaking is available for inspection

in the TSCA Nonconfidential Information Center (also known as the TSCA

Public Docket Office), Rm. NE B607, 401 M St., SW., Washington, DC from

12 noon to 4:00 p.m., Monday through Friday, except legal holidays.

V. Regulatory Assessment Requirements

A. Executive Order 12866

Under Executive Order 12866 (58 FR 51735, October 4, 1993), the

Agency must determine whether the regulatory action is ``significant''

and therefore subject to all the requirements of the Executive Order

(i.e., Regulatory Impact Analysis and review by the Office of

Management and Budget (OMB)). Under section 3(f), the order defines

``significant'' as those actions likely to lead to a rule (1) having an

annual effect on the economy of $100 million or more, or adversely and

materially affecting a sector of the economy, productivity,

competition, jobs, the environment, public health or safety, or State,

local, or tribal governments or communities (aka ``economically

significant''); (2) creating serious inconsistency or otherwise

interfering with an action taken or planned by another agency; (3)

materially altering the budgetary impacts of entitlements, grants, user

fees, or loan programs; or (4) raising novel legal or policy issues

arising out of legal mandates, the President's priorities, or the

principles set forth in this Executive Order. Pursuant to the terms of

this order, EPA has determined that this rule would not be

``significant''.

B. Regulatory Flexibility Act

Under the Regulatory Flexibility Act, 5 U.S.C. 601 et seq., EPA is

certifying that revocation of this test rule will not have a

significant impact on a substantial number of small businesses because

only the 24 manufacturers who signed the ECAs, which will replace the

revoked test rule, will be responsible for conducting and paying for

the testing. None of these manufacturers are small businesses.

C. Paperwork Reduction Act

There are no information collection requirements associated with

this revocation covered under the provisions of the Paperwork Reduction

Act of 1980, 44 U.S.C. 3501 et seq.

List of Subjects in 40 CFR Part 799

Chemicals, Chemical export, Environmental protection, Hazardous

substances, Health effects, Laboratories, Reporting and recordkeeping

requirements, Testing.

Dated: January 10, 1995.

Lynn R. Goldman,

Assistant Administrator for Prevention, Pesticides and Toxic

Substances.

Therefore, 40 CFR, chapter I, subchapter R, part 799 is amended as

follows:

PART 799--[AMENDED]

1. The authority citation for part 799 continues to read as

follows:

Authority: 15 U.S.C. 2603, 2611, 2625.

Sec. 799.5050--[Removed]

2. By removing Sec. 799.5050.

[FR Doc. 95-1673 Filed 1-20-95; 8:45 am]

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