8578 Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices

ENVIRONMENTAL PROTECTION

AGENCY

[OPPTS–41046; FRL–5580–9]

Thirty-Ninth Report of the TSCA

Interagency Testing Committee (ITC) to

the Administrator; Receipt of Report,

Request for Comments

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice.

SUMMARY: The TSCA Interagency

Testing Committee (ITC), established

under section 4(e) of the Toxic

Substances Control Act (TSCA),

transmitted its Thirty-Ninth Report to

the Administrator of the EPA on

November 27, 1996. In the Thirty-Ninth

Report, which is included with this

Notice, the ITC revised the TSCA

section 4(e) Priority Testing List by

recommending 2,4,6-tribromophenol,

re-recommending 23 nonylphenol

ethoxylates and removing 5 siloxanes.

Moreover, the ITC requested that EPA

stay certain provisions in the Agency’s

October 29, 1996, TSCA section 8(a) and

8(d) information reporting rules for the

nonylphenol ethoxylates recommended

in the ITC’s Thirty-Eighth Report

There are no designated or

recommended with intent-to-designate

chemicals or chemical groups in the

Thirty-Ninth Report. EPA invites

interested persons to submit written

comments on the Report.

DATES: Written comments on the ThirtyNinth ITC Report should be received by

March 27, 1997.

ADDRESSES: Comments on the ThirtyNinth Report should be submitted to

both the ITC and the TSCA Docket.

Send one copy of written comments to:

John D. Walker, ITC Executive Director

(7401), U.S. Environmental Protection

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

DC 20460. Send six copies of written

comments to: Document Control Office,

Rm. ET-G–099, Office of Pollution

Prevention and Toxics (7407),

Environmental Protection Agency, 401

M St., SW., Washington, DC 20460. All

submissions should bear the docket

number OPPTS–41046.

Comments may also be submitted

electronically by sending electronic

mail (e-mail) to:

walker.johnd@epamail.epa.gov or to the

EPA at: ncic@epamail.epa.gov.

Electronic comments are preferred by

the ITC. Electronic comments must be

submitted as an ASCII file avoiding the

use of special characters and any form

of security encryption. Comments will

be accepted on disks in WordPerfect

5.1/6.1 file format or ASCII file format.

All comments in electronic form must

be identified by the docket number

OPPTS–41046. No TSCA ‘‘Confidential

Business Information’’ (CBI) should be

submitted through e-mail. Electronic

comments on the Thirty-Ninth Report

may be filed online at many Federal

Depository Libraries. Additional

information on electronic submissions

can be found in Unit IV of this

document.

The public record supporting this

action, including comments, is available

for public inspection in the TSCA NonConfidential Information Center (NCIC),

Rm. NE-B–607 at the address noted

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

through Friday, except legal holidays.

FOR FURTHER INFORMATION CONTACT:

Susan B. Hazen, Director,

Environmental Assistance Division

(7408), Office of Pollution Prevention

and Toxics, Environmental Protection

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

DC 20460, (202) 554–1404, TDD (202)

554–0551.

SUPPLEMENTARY INFORMATION: EPA has

received the TSCA Interagency Testing

Committee’s Thirty-Ninth Report to the

Administrator.

I. Background

TSCA (Pub. L. 94–469, 90 Stat. 2003

et seq; 15 U.S.C. 260l et seq.) authorizes

the Administrator of the EPA to

promulgate regulations under section

4(a) requiring testing of chemicals and

chemical groups in order to develop

data relevant to determining the risks

that such chemicals and chemical

groups may present to health or the

environment. Section 4(e) of TSCA

established the ITC to recommend

chemicals and chemical groups to the

Administrator of the EPA for priority

testing consideration. Section 4(e)

directs the ITC to revise the TSCA

section 4(e) Priority Testing List at least

every 6 months.

II. The ITC Thirty-Ninth Report

The most recent revisions to the

Priority Testing List are included in the

ITC’s Thirty-Ninth Report. The Report

was received by the EPA Administrator

on November 27, 1996, and is included

in this Notice. The Report recommends

2,4,6-tribromophenol, re-recommends

23 nonylphenol ethoxylates and

removes 5 siloxanes from the Priority

Testing List. 2,4,6-Tribromophenol is

being recommended to meet the data

needs of the National Institute of

Environmental Health Sciences

(NIEHS). The nonylphenol ethoxylates

are being re-recommended to meet the

data needs of the Department of the

Interior (DOI), the EPA, the Food and

Drug Administration (FDA) and the

NIEHS and to eliminate any ambiguities

in TSCA section 8(a) and 8(d) reporting

resulting from the previous use of

alternate Chemical Abstracts Service

(CAS) registry numbers in the ITC’s

Thirty-Eighth Report (61 FR 39832; July

30, 1996; FRL–5379–2). The ITC reexamined these alternate CAS registry

numbers and determined that five were

not associated with any of the listed

nonylphenol ethoxylate chemical

names. In the Thirty-Ninth Report, the

ITC revised the list of nonylphenol

ethoxylates by providing Ninth

Collective Index names for all CASnumbered nonylphenol ethoxylates,

including the five not previously

associated with a unique chemical

name. This process eliminated the need

for alternate CAS registry numbers. The

ITC requested that the EPA stay certain

provisions in the October 29, 1996,

TSCA section 8(a) and 8(d) rules (61 FR

55871; FRL–5397–9) promulgated for

the nonylphenol ethoxylates originally

recommended in the ITC’s Thirty-Eighth

Report (61 FR 39832; July 30, 1996;

FRL–5379–2). The EPA issued the stay

which was published on December 11,

1996 (61 FR 65186; FRL–5577–5).

Nothing in this Notice changes the

status of the stayed rules affecting the

nonylphenol ethoxylates. These rules

remain stayed, and the EPA will address

their future status in a subsequent

Federal Register Notice.

III. Status of the Priority Testing List

The current TSCA section 4(e) Priority

Testing List contains 1 individual

chemical and 11 chemical groups; of

these, 4 chemical groups were

designated for testing.

IV. Electronic Comments

The EPA invites interested persons to

submit detailed comments on the ITC’s

Thirty-Ninth Report.

A record has been established for this

Notice under docket number OPPTS–

41046 including comments submitted

electronically as described below. A

public version of this record, including

printed paper versions of electronic

comments, which does not contain any

information claimed as TSCA

‘‘Confidential Business Information’’

(CBI), is available for inspection from 12

noon to 4 p.m., Monday through Friday,

excluding legal holidays. The public

record is located in the TSCA NonConfidential Information Center, Rm.

NE-B–607, Environmental Protection

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

DC 20460. Electronic comments can be

sent directly to the ITC at:

walker.johnd@epamail.epa.gov and to

the EPA at: ncic@epamail.epa.gov.
Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices 8579

Electronic comments must be

submitted as an ASCII file avoiding the

use of special characters and any form

of security encryption. Comments will

be accepted on disks in WordPerfect

5.1/6.1 file format or ASCII file format.

The official record for the ITC’s

Thirty-Ninth Report, as well as the

public version as described above, will

be kept in paper form. Accordingly, EPA

will transfer all comments received

electronically into printed, paper form

as they are received and will place the

paper copies in the official record which

will also include all comments

submitted directly in writing. The

official record is the paper record

maintained at the EPA address in

‘‘ADDRESSES’’ at the beginning of this

document.

Authority: 15 U.S.C. 2603.

Dated: February 13, 1997.

Charles M. Auer,

Director, Chemical Control Division, Office

of Pollution Prevention and Toxics.

Administrator, U.S. Environmental

Protection Agency

Summary

This is the 39th Report of the TSCA

Interagency Testing Committee (ITC) to

the Administrator of the U.S.

Environmental Protection Agency

(EPA). In this Report, the ITC is revising

its TSCA section 4(e) Priority Testing

List by recommending 2,4,6-

tribromophenol, re-recommending 23

nonylphenol ethoxylates and removing

5 siloxanes. 2,4,6-Tribromophenol is

being recommended to meet the data

needs of the National Institute of

Environmental Health Sciences

(NIEHS). The nonylphenol ethoxylates

are being re-recommended to meet the

data needs of the Department of the

Interior (DOI), the EPA, the Food and

Drug Administration (FDA) and the

NIEHS and to eliminate any ambiguities

in TSCA section 8(a) and 8(d) reporting

resulting from the previous use of

alternate CAS numbers in the ITC’s 38th

Report (61 FR 39832, July 30, 1996).

Comments on this Report should be

submitted both to the ITC and the TSCA

Public Docket. The revised TSCA

section 4(e) Priority Testing List follows

as Table 1.

TABLE 1.— THE TSCA SECTION 4(e) Priority Testing List (November 1996)

Report Date Chemical/Group Action

26 ............ May 1990 10 Isocyanates Recommended with intent-to-designate

27 ............ November 1990 62 Aldehydes Recommended with intent-to-designate

28 ............ May 1991 Chemicals with Low Confidence RfD

Acetone

Thiophenol

Designated

29 ............ November 1991 10 Alkyl-, bromo-, chloro-, hydroxymethyl diaryl

ethers

Recommended

30 ............ May 1992 8 Siloxanes Recommended

31 ............ January 1993 24 Chemicals with insufficient dermal absorption

rate data

Designated

32 ............ May 1993 32 Chemicals with insufficient dermal absorption

rate data

Designated

35 ............ November 1994 24 Chemicals with insufficient dermal absorption

rate data

Designated

36 ............ May 1995 10 High Production Volume Chemicals (HPVCs) Recommended

37 ............ November 1995 28 Alkylphenols and Ethoxylates Recommended

39 ............ November 1996 23 Nonylphenol Ethoxylates Recommended

39 ............ November 1996 2,4,6-Tribromophenol Recommended

I. Background

The TSCA Interagency Testing

Committee (ITC) was established by

section 4(e) of the Toxic Substances

Control Act (TSCA) ‘‘to make

recommendations to the Administrator

respecting the chemical substances and

mixtures to which the Administrator

should give priority consideration for

the promulgation of a rule for testing

under section 4(a).... At least every 6

months..., the Committee shall make

such revisions in the List as it

determines to be necessary and to

transmit them to the Administrator

together with the Committee’s reasons

for the revisions’’ (Pub. L. 94–469, 90

Stat. 2003 et seq., 15 U.S.C. 2601 et

seq.). Since its creation in 1976, the ITC

has submitted 38 semi-annual Reports

to the EPA Administrator transmitting

the Priority Testing List and its

revisions. These Reports have been

published in the Federal Register and

are also available from the ITC. The ITC

meets monthly and produces its

revisions of the List with the help of

staff and technical contract support

provided by EPA. ITC members and

support personnel are listed at the end

of this Report.

II. ITC’s Activities During this

Reporting Period (May to October,

1996)

Alkylphenols and ethoxylates. The

ITC-Chemical Manufacturers

Association (CMA) Alkylphenols and

Ethoxylates Dialog Group met to discuss

environmental monitoring, ecological

effects, biodegradation and mammalian

toxicology studies. This Dialog Group

was established to facilitate the ITC’s

retrieval of information on uses,

exposures and effects of alkyphenols

and ethoxylates, and the CMA’s

understanding of data needed by the

DOI, the FDA, the EPA and the NIEHS.

Siloxanes. The ITC-Silicones

Environmental Health and Safety

Council (SEHSC) Dialog Group met to

discuss ongoing health effects and

exposure studies. This Dialog Group

was established to facilitate the ITC’s

retrieval of information on uses,

exposures and effects of siloxanes, and

the SEHSC’s understanding of data

needed by the FDA.

Isocyanates. During this reporting

period, the ITC received information

from the CMA’s Diisocyanates Panel.

The ITC’s Isocyanates Subcommittee

will review this information and discuss

potential consumer uses, occupational

exposures and health effects of

isocyanates with the CMA Panel.

High Production Volume Chemicals

(HPVCs). Through its 36th Report and

letters to manufacturers and importers

of HPVCs, the ITC is receiving use and

exposure data for the 10 HPVCs

remaining on the Priority Testing List.

The ITC is reviewing these data.

Diaryl ethers. The ITC has identified

manufacturers and importers of diaryl
8580 Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices

ethers and is interested in working with

them to obtain use and exposure data.

Diaryl ethers were recommended in the

ITC’s 29th Report (56 FR 67424,

December 30, 1991). An invitation to

discuss use and exposure data and to

develop Structure Activity

Relationships for diaryl ethers was

announced in the ITC’s 38th Report (61

FR 39832, July 30, 1996)(FRL–5379–2).

2,4,6-Tribromophenol.

Representatives of the ITC met with the

CMA’s Brominated Flame Retardants

Industry Panel (BFRIP) Manager and

representatives from a 2,4,6-

tribromophenol manufacturer to discuss

the data needs of the NIEHS. The ITC

representatives provided the CMA with

a copy of the National Toxicology

Program (NTP) data summary for 2,4,6-

tribromophenol (Ref. 5, NTP, 1996). The

2,4,6-tribromophenol manufacturer’s

representatives provided the ITC with a

list of health effects, chemical fate, and

ecological effects studies that were

previously submitted under TSCA

section 8(d) and reviewed by the ITC.

These representatives also provided the

ITC with a list of 2,4,6-tribromophenol

producers, applications, commercial

activities and sales statistics. The ITC is

interested in promoting a dialog that is

mutually beneficial to the NIEHS and

the BFRIP.

III. TSCA Section 8 Reporting

Following receipt of the ITC’s Report

and the addition of chemicals to the

Priority Testing List, EPA’s Office of

Pollution Prevention and Toxics adds

new chemicals from the List to TSCA

section 8(a) and 8(d) rules that require

manufacturers and importers of these

chemicals to submit TSCA section 8(a)

production and exposure data and

manufacturers, importers and

processors of the listed chemicals to

submit TSCA section 8(d) health and

safety studies within 60 days of the

rule’s effective date. Unless otherwise

noted in Unit IV A of this ITC Report,

the ITC is requesting that the EPA

exempt manufacturers and importers of

chemicals added to the List from

submitting studies conducted on

mixtures (e.g., formulated products)

containing a subject substance at a level

below 1 percent of the mixture, unless

a purpose of the study includes the

investigation of the effects of an 8(d)

rule-listed substance at levels below 1

percent (40 CFR 716.20(b)(4)).

TSCA section 8(a) and 8(d)

submissions are indexed and

maintained by EPA. The ITC reviews

the TSCA section 8(a) and 8(d)

information and other available data on

chemicals and chemical groups (e.g.,

TSCA section 8(e) ‘‘substantial risk’’

notices, ‘‘For Your Information’’ (FYI)

submissions to EPA, and published

papers) to determine if revisions to the

List are necessary. Revisions can

include changing a general

recommendation to a specific

designation for testing action by the

EPA Administrator within 12 months,

modifying the recommended testing, or

removing the chemical or chemical

group from the List.

IV. Revisions to the TSCA Section 4(e)

Priority Testing List

Revisions to the TSCA section 4(e)

Priority Testing List are summarized in

Table 2.

TABLE 2.—REVISIONS TO THE TSCA SECTION 4(e) PRIORITY TESTING LIST

CAS No. Chemical Name Action Date

118–79–6 .............. 2,4,6-Tribromophenol Recommended 11/96

Nonylphenol ethoxylates Recommended 11/96

7311–27–5 ............ Ethanol, 2-[2-[2-[2-(4-nonylphenoxy) ethoxy]ethoxy]ethoxy]-

9016–45–9 ............ Poly(oxy-1,2-ethanediyl), .alpha.-(nonylphenyl)-.omega.-hydroxy20427–84–3 .......... Ethanol, 2-[2-(4-nonylphenoxy)ethoxy]-

20636–48–0 .......... 3,6,9,12-Tetraoxatetradecan-1-ol, 14-(4-nonylphenoxy)-

26027–38–3 .......... Poly(oxy-1,2-ethanediyl), .alpha.-(4-nonylphenyl)-.omega.-hydroxy26264–02–8 .......... 3,6,9,12-Tetraoxatetradecan-1-ol, 14-(nonylphenoxy)-

26571–11–9 .......... 3,6,9,12,15,18,21,24-Octaoxahexacosan-1-ol, 26-(nonylphenoxy)-

27176–93–8 .......... Ethanol, 2-[2-(nonylphenoxy)ethoxy]-

27177–01–1 .......... 3,6,9,12,15-Pentaoxaheptadecan-1-ol, 17-(nonylphenoxy)-

27177–05–5 .......... 3,6,9,12,15,18,21-Heptaoxatricosan-1-ol, 23-(nonylphenoxy)-

27177–08–8 .......... 3,6,9,12,15,18,21,24,27-Nonaoxanonacosan-1-ol, 29-(nonylphenoxy)-

27986–36–3 .......... Ethanol, 2-(nonylphenoxy)-

37205–87–1 .......... Poly(oxy-1,2-ethanediyl), .alpha.-(isononylphenyl)-.omega.-hydroxy51938–25–1 .......... Poly(oxy-1,2-ethanediyl), .alpha.-(2-nonylphenyl)-.omega.-hydroxy65455–72–3 .......... 3,6,9,12,15,18,21,24,27-Nonaoxanonacosan-1-ol, 29-(isononylphenoxy)-

68412–54–4 .......... Poly(oxy-1,2-ethanediyl), .alpha.-(nonylphenyl)-.omega.-hydroxy-, branched

98113–10–1 .......... NP 9

127087–87–0 ........ Poly(oxy-1,2-ethanediyl), .alpha.-(4-nonylphenyl)-.omega.-hydroxy-,

branched

152143–22–1 ........ Poly(oxy-1,2-ethanediyl), .alpha.-(4-nonylphenyl)-.omega.-hydroxy-,

branched, phosphates

NAa ....................... Nonoxynol-2

NA ......................... Nonoxynol-3

NA ......................... Nonoxynol-7

NA ......................... .alpha.-(4-Nonylphenol)-.omega.-hydroxypoly-(oxyethylene)-

5 Siloxanes Remove previously Recommended chemicals11/96

69430–24–6 .......... Cyclopolydimethylsiloxane (Dx)

68083–14–7 .......... Dimethyl, diphenyl siloxanes and silicones

67762–90–7 .......... Dimethyl silicones and siloxanes, reaction products with silica

68037–74–1 .......... Dimethylmonomethylpolysiloxanes

70131–67–8 .......... Dimethyl silicones and siloxanes hydroxy terminated

aNot Assigned.
Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices 8581

A. Chemicals Added to the Priority

Testing List

Recommendations

a. 2,4,6-Tribromophenol— rationale

for recommendation. The ITC is

recommending 2,4,6-tribromophenol at

this time because the NIEHS needs

chronic toxicology and 2-year

carcinogenesis study data. As part of its

continuing efforts to coordinate testing

activities, the ITC is recommending and

not designating 2,4,6-tribromophenol

because it is currently promoting a

dialog between a 2,4,6-tribromophenol

manufacturer and the NIEHS to explain

the need for chronic toxicity and 2–year

carcinogenesis study data.

Background. Previous activities of the

ITC, EPA and NTP for 2,4,6-

tribromophenol are summarized below.

ITC. In the ITC’s 25th Report, 2,4,6-

tribromophenol and six other

brominated flame retardants were

recommended for chronic health effects

testing, chronic ecological effects

testing, and physical/chemical

properties and persistence testing (54

FR 51114, December 12, 1989). In

response to the 25th Report, as noted

below, the EPA required the submission

of TSCA section 8(a) and 8(d) data.

In the ITC’s 33rd Report, 2,4,6-

tribromophenol was removed from the

Priority Testing List to give adequate

priority to testing needs for other

chemicals, e.g., those with U.S.

Government data needs (59 FR 3764,

January 26, 1994). At the time 2,4,6-

tribromophenol was removed from the

List, the ITC acknowledged that there

were no existing U.S. Government data

needs, but agreed to reconsider the

chemical if data were needed in the

future.

At this time, the ITC is requesting that

the EPA not promulgate additional

TSCA section 8 rules for 2,4,6-

tribromophenol for the following

reasons. First, the ITC has reviewed the

TSCA section 8(a) and (d) data

submitted under the previouslypromulgated rules. Second, under the

previously-promulgated TSCA section

8(d) rule, the ITC will learn of any new

studies that are initiated. Third, the ITC

believes that a dialog with the U.S.

producer is likely to provide use and

other relevant data that could not be

obtained by re-promulgating these rules.

EPA. 2,4,6-Tribromophenol was

included in a 1987 EPA TSCA section

4 test rule requiring that manufacturers

and importers of 12 chemicals test for

the presence of certain chlorinated and

brominated dibenzo-p-dioxins and

dibenzofurans (52 FR 21412, June 5,

1987). None of the seven 2,4,6-

tribromophenol samples that were

analyzed contained concentrations of

brominated dibenzo-p-dioxins and

dibenzofurans that were above the

levels of quantitation (0.1 ppb for

2,3,7,8-tetrabrominated dibenzo-pdioxin and 1 ppb for 2,3,7,8-

tetrabrominated dibenzofuran).

2,4,6-Tribromophenol was also

included in 1989 EPA TSCA section 8

rules promulgated for the ITC. These

rules required the submission of

production and exposure data and

unpublished health and safety data

under TSCA sections 8(a) and 8(d),

respectively (54 FR 51131, December 12,

1989).

NTP. At the July 15, 1996 meeting of

the NTP Interagency Committee for

Chemical Evaluation and Coordination,

the NIEHS identified data needs for

2,4,6-tribromophenol. The NIEHS needs

chronic toxicology and 2–year

carcinogenesis study data for 2,4,6-

tribromophenol based on the absence of

toxicology and carcinogenicity data and

carcinogenicity data for 2,4,6-

trichlorophenol, (Ref. 5, NTP, 1996).

Existing Data. 2,4,6-Tribromophenol

is a chemical intermediate that is

produced in closed process equipment,

kept within that equipment and reacted

to make flame retardants (Ref. 1, GLCC,

1996a). Recent production volumes

ranged from 1 to 15 million pounds

(Ref. 6, Walker, 1994).

The number of employees involved in

the production, packaging, or handling

of 2,4,6-tribromophenol is quite small.

While the exact number of operators is

confidential information, less than 50

workers have the potential for

intermittent exposure to 2,4,6-

tribromophenol during their normal

workday (Ref.1, GLCC, 1996a). The use

of closed processes limits potential

exposure, but even this exposure is

controlled through the use of local

exhaust ventilation, personal protective

equipment and other industrial hygiene

practices where dust or vapor exposure

might occur (Ref. 1, GLCC, 1996a).

Flaked 2,4,6-tribromophenol contains

particles (estimated to be 1 to 10 mm)

which do not easily become airborne.

During domestic production of 2,4,6-

tribromophenol, air emissions are

regulated by State permits and releases

to surface waters either do not occur or

occur after discharge to Publicly Owned

Treatment Works (Ref. 1, GLCC, 1996a).

The only operation where 2,4,6-

tribromophenol is not in closed reactors

or piping is the flaking and packaging

operation. Vapors and fine particulates

from this process are controlled by a

local exhaust system. Using a ‘‘worst

case’’ assumption that the

manufacturing facility operated 24

hour/day, 365 days per year (8,760

hours), annual point source emissions

would be less than 90 pounds per year

(Ref. 2, GLCC, 1996b).

2,4,6-Tribromophenol was not found

to be mutagenic in the Ames assay (Ref.

8, Zeiger et al., 1987) or in the mouse

lymphoma assay (Ref. 4, NCI, 1996).

Doses ranging from 2,000 to 8,000 mg/

kg were required to produce acute

effects in laboratory animals by oral,

dermal or inhalation exposures (Ref. 5,

NTP, 1996).

The TSCA section 8 data for 2,4,6-

tribromophenol were recently published

in two reviews (Refs. 6 and 7, Walker,

1994; 1996). Data cited in the 1996

review indicated that 2,4,6-

tribromophenol can be highly toxic to

fish (LC50 values <1 mg/L) but less toxic

to daphnids, in acute toxicity tests.

Health effects studies cited in the 1994

review are summarized below.

In a 28–day dermal toxicity study,

groups of 4 rabbits/sex/dose were used.

Doses of 0, 100, 300 and 1,000 mg/kg

were applied as skin suspensions 5 days

a week for 4 weeks. At the highest dose

(1,000 mg/kg) 1 male rabbit died. At

doses of 100 and 300 mg/kg 2,4,6-

tribromophenol was slightly irritating,

but there were no treatment-related

effects on body weight, clinical

chemistry or organ weights (Ref. 6,

Walker, 1994).

In a developmental toxicity screening

study, groups of 5 pregnant rats were

administered gavage doses of 2,4,6-

tribromophenol in corn oil from

gestation day 6 to 15. Doses of 0, 10, 30,

100, 300, 1,000 and 3,000 mg/kg/day

were administered. All rats receiving

3,000 mg/kg/day died; animals receiving

1,000 mg/kg/day showed increased post

implantation losses and a slight

decrease in number of viable fetuses.

Rats receiving 300 mg/kg/day or less

showed no compound-related

differences in maternal body weight,

number of viable fetuses, resorptions,

implantations or corpora lutea when

compared with the controls (Ref. 6,

Walker, 1994).

In an inhalation study, groups of 5

male and 5 female rats were exposed to

0, 0.1 and 0.9 mg/L 2,4,6-

tribromophenol for 6 hours/day, 5 days/

week for 3 weeks. Exposures to both

doses of 2,4,6-tribromophenol produced

liver and kidney lesions. At necropsy, 4/

5 male and 5/5 female rats in the 0.1

mg/L dose group were emaciated (Ref. 6,

Walker, 1994).

The NIEHS data needs are supported

by carcinogenicity data for a close

structural analog, 2,4,6-trichlorophenol

(CAS No. 88–06–2). In a feeding study

2,4,6-trichlorophenol was a carcinogen

in male rats and male and female mice,

inducing lymphomas or leukemias in
8582 Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices

male F344 rats; and increasing the

incidence of hepatocellular carcinomas

or adenomas in male and female

B6C3F1 mice (Ref. 3, NCI, 1979).

b. Nonylphenol ethoxylates—

rationale for recommendation. Twentythree (23) nonylphenol ethoxylates are

being re-recommended to eliminate any

ambiguities in TSCA section 8(a) and

8(d) reporting resulting from the

previous use of alternate CAS numbers

in the ITC’s 38th Report (61 FR 39832,

July 30, 1996).

Background. Eighteen (18)

nonylphenol ethoxylates were

recommended in the ITC’s 38th Report

(61 FR 39832, July 30, 1996). Alternate

CAS registry numbers were listed for

some of these nonylphenol ethoxylates.

The use of alternate CAS numbers

produced some ambiguities in the TSCA

section 8(a) and 8(d) rules that were

promulgated for the nonylphenol

ethoxylates (61 FR 55871, October 29,

1996). The ITC re-examined these

alternate CAS registry numbers and

determined that five were not associated

with any of the listed nonylphenol

ethoxylate chemical names. The ITC

revised the list of nonylphenol

ethoxylates by providing ninth

collective index names for all CASnumbered nonylphenol ethoxylates,

including the five not previously

associated with a unique chemical

name. This process eliminated the need

for alternate CAS registry numbers. The

ITC is requesting that the EPA stay

certain provisions in the October 29,

1996 TSCA section 8(a) and 8(d) rules

promulgated for nonylphenol

ethoxylates (61 FR 55871) because of

ambiguities in reporting requirements

associated with the use of alternate CAS

registry numbers in the ITC’s 38th

Report (61 FR 39832, July 30, 1996). The

ITC is requesting that the EPA

promulgate the TSCA section 8(a) and

8(d) rules using the 23 nonylphenol

ethoxylates in Table 2 of this ITC

Report.

B. Chemicals Removed from the Priority

Testing List

Silicone chemicals. Fifty-six (56)

silicone chemicals were recommended

for health effects testing in the ITC’s

30th Report to meet the data needs of

the Food and Drug Administration

(FDA) (57 FR 30608, July 9, 1992). After

this recommendation, the ITC’s

Silicones Subcommittee established a

Dialog Group with the Silicones

Environmental Health and Safety

Council (SEHSC). The ITC-SEHSC

Dialog Group has discussed

unpublished toxicity data, current use

and exposure data, and developed a

prototype computer file of physical and

chemical properties, health effects and

use data that could be used by other

government and trade organizations. As

a result of the Dialog Group’s

discussions, the ITC removed 43 of the

previously-recommended silicone

chemicals from the Priority Testing List

in its 37th Report (61 FR 4188, February

2, 1996; FRL–4991–6). As a result of

further Dialog Group discussions, the

ITC is removing five more siloxanes

from the List in this Report (Table 3).

The eight siloxanes remaining on the

List are included in Table 4.

TABLE 3.—PREVIOUSLY-RECOMMENDED SILICONE CHEMICALS REMOVED FROM THE PRIORITY TESTING LIST

CAS No. Chemical Name Removal Rationale

69430–24–6 .... Cyclopolydimethylsiloxane (Dx) Toxicity of cyclopolydimethylsiloxane is likely to be predicted from testing

octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and

dodecamethylcyclohexasiloxane (D6) (see Table 4). Cyclopolydimethylsiloxane is

used only as a site-limited intermediate to manufacture D4, D5 and D6.

68083–14–7 .... Dimethyl, diphenyl siloxanes and

silicones

Low exposure potential based on annual production volume and specialized uses.

67762–90–7 .... Dimethyl silicones and siloxanes, reaction products with silicaToxicity of siloxane polymers bearing CAS numbers 67762–90–7, 68037–74–1 and

70131–67–8 is likely to be predicted from testing dimethyl silicones and siloxanes

bearing CAS number 63148–62–9 (see Table 4). Dimethyl silicones and siloxanes is

a siloxane polymer of lower molecular weight, lower cross-linking ability and greater

bioavailability potential than these 3 siloxane polymers.

68037–74–1 .... Dimethylmonomethylpolysiloxanes Toxicity of siloxane polymers bearing CAS numbers 67762–90–7, 68037–74–1 and

70131–67–8 is likely to be predicted from testing dimethyl silicones and siloxanes

bearing CAS number 63148–62–9 (see Table 4). Dimethyl silicones and siloxanes is

a siloxane polymer of lower molecular weight, lower cross-linking ability and greater

bioavailability potential than these 3 siloxane polymers.

70131–67–8 .... Dimethyl silicones and siloxanes

hydroxy terminated

Toxicity of siloxane polymers bearing CAS numbers 67762–90–7, 68037–74–1 and

70131–67–8 is likely to be predicted from testing dimethyl silicones and siloxanes

bearing CAS number 63148–62–9 (see Table 4). Dimethyl silicones and siloxanes is

a siloxane polymer of lower molecular weight, lower cross-linking ability and greater

bioavailability potential than these 3 siloxane polymers.

The eight siloxanes remaining on the

Priority Testing List shown in table 4.

TABLE 4.—SILOXANES REMAINING ON

THE PRIORITY TESTING LIST

CAS No. Chemical Name

CYCLIC

SILOXANES.

556–67–2 ... Octamethylcyclotetrasiloxane

(D4)

541–02–6 ... Decamethylcyclopentasiloxane (D5)

TABLE 4.—SILOXANES REMAINING ON

THE PRIORITY TESTING LIST—Continued

CAS No. Chemical Name

540–97–6 ... Dodecamethylcyclohexasiloxane (D6)

LINEAR

SILOXANES.

107–46–0 ... Hexamethyldisiloxane (L2)

107–51–7 ... Octamethyltrisiloxane (L3)

141–62–8 ... Decamethyltetrasiloxane (L4)

141–63–9 ... Dodecamethylpentasiloxane

(L5)

TABLE 4.—SILOXANES REMAINING ON

THE PRIORITY TESTING LIST—Continued

CAS No. Chemical Name

POLYMERS.

63148–62–9 Dimethyl silicones and

siloxanes

9006–65–9a.

9016–00–6a.

aAlternate CAS numbers are listed for this

chemical.
Federal Register / Vol. 62, No. 37 / Tuesday, February 25, 1997 / Notices 8583

References

(1) GLCC. November 13, 1996, Letter

from Mr. Robert C. Campbell, TSCA

Compliance Manager, Great Lakes

Chemical Corporation (GLCC), West

Lafayette, Indiana to Dr. John D. Walker,

Executive Director, ITC, U.S. EPA,

Washington, DC (1996a).

(2) GLCC. November 15, 1996, Letter

from Mr. Robert C. Campbell, TSCA

Compliance Manager, Great Lakes

Chemical Corporation (GLCC), West

Lafayette, Indiana to Dr. John D. Walker,

Executive Director, ITC, U.S. EPA,

Washington, DC (1996b).

(3) NCI. Bioassay of 2,4,6-

trichlorophenol for possible

carcinogenicity (CAS No. 88–06–2)

(Technical Report Series No. 155;

Department of Health Education and

Welfare (DHEW) Publication No. (NIH)

79–1711). DHEW, Washington, DC. 115

pp. (1979).

(4) NCI. NCI/DCB Short-term test

program. Ames Salmonella

typhimurium/mouse lymphoma

L5178Y, H. Seifried, Ph.D., Project

Officer (1996).

(5) NTP. Draft NTP data summary for

2,4,6-tribromophenol (CAS No. 118–79–

6). NTP, Research Triangle Park, NC. 19

pp. (1996).

(6) Walker, J.D. Testing decisions of

the TSCA Interagency Testing

Committee for brominated flame

retardants: A review of decisions and

health and safety data. pp. 185–220. In

The Future of Fire Retarded Materials:

Applications and Regulation. Fire

Retardant Chemicals Association,

Lancaster, PA. (1994).

(7) Walker, J.D. Testing decisions of

the TSCA Interagency Testing

Committee for chemicals on Canada’s

Domestic Substances List and Priority

Substances List: Di-tert-butylphenol,

ethyl benzene, brominated flame

retardants, phthalate esters,

chloroparaffins, chlorinated benzenes

and anilines. pp. 18–54. In T.W.

LaPoint, F.T. Price, and E.E. Little (eds.),

Environmental Toxicology and Risk

Assessment: Fourth Volume, ASTM STP

1241, ASTM, Philadelphia (1996).

(8) Zeiger, E., B. Anderson, S.

Haworth, T. Lawlor, K. Mortelmans and

W. Speck. Salmonella mutagenicity

tests: III. Results from testing of 255

chemicals. Environmental Molecular

Mutagenicity 9 (Suppl.9), 1–110 (1987).

TSCA Interagency Testing Committee

Statutory Organizations and Their

Representatives

Council on Environmental Quality

Brad Campbell, Member

Douglas Sanders, Alternate

Department of Commerce

Edward White, Member

Environmental Protection Agency

David R. Williams, Member

Lois Dicker, Alternate

National Cancer Institute

Victor Fung, Member, Chair

Harry Seifried, Alternate

National Institute of Environmental Health

Sciences

William Eastin, Member

H.B. Matthews, Alternate

National Institute for Occupational Safety

and Health

Henryka Nagy, Member, Vice Chair

David A. Dankovic, Alternate

National Science Foundation

Linda Duguay, Member

Occupational Safety and Health

Administration

Lyn Penniman, Member

Christine Whittaker, Alternate

Liaison Organizations and Their

Representatives

Agency for Toxic Substances and Disease

Registry

William Cibulas, Member

Consumer Product Safety Commission

Val Schaeffer, Member

Lakshmi C. Mishra, Alternate

Department of Agriculture

Clifford Rice, Member

Department of Defense

David A. Macys, Member

Department of the Interior

Barnett A. Rattner, Member

Food and Drug Administration

Edwin J. Matthews, Member

Raju Kammula, Alternate

National Library of Medicine

Vera Hudson, Member

National Toxicology Program

NIEHS, FDA and NIOSH Members

Counsel

Mary Ellen Levine, Office of General

Counsel, EPA

Technical Support Contractor

Syracuse Research Corporation

ITC Staff

John D. Walker, Executive Director

Norma S.L. Williams, Executive

Assistant, TSCA Interagency Testing

Committee, U.S. EPA/OPPT (MC/7401), 401

M St., SW., Washington, DC 20460, Phone

(202) 260–1825, Fax (202) 260–7895.

Internet:walker.johnd@epamail.epa.gov

[FR Doc. 97–4620 Filed 2–24–97; 8:45 am]

BILLING CODE 6560–50–F