### 4188 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

ENVIRONMENTAL PROTECTION AGENCY

[OPPTS–41044; FRL–4991–6] Thirty-Seventh Report of the TSCA Interagency Testing Committee to the Administrator; Receipt of Report, Request for Comments, Solicitation of Use and Exposure Data

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 37th Report to the Administrator of the EPA on November 22, 1995. In its 37th Report, which is included with this notice, the ITC revised the Priority Testing List by adding a group of 28 alkylphenols and alkylphenol ethoxylates to the List for consideration by the EPA Administrator for promulgation of test rules under section 4(a) of the Act. The ITC also removed 43 previously-recommended silicone chemicals and 5 isocyanates. The ITC’s reasons for removing these chemicals from the List are described in the 37th Report. As noted in this Report, the ITC is soliciting use and exposure data for 9 of the 12 High Production Volume Chemicals that were recommended in its 36th Report (60 FR 42982, August 17, 1995) and consumer use and data for the 10 isocyanates remaining on the List. There are no designated or recommended with intent-to-designate chemicals or chemical groups in the 37th Report. EPA invites interested persons to submit written comments on the Report.
DATES : Written comments on the 37th ITC Report should be submitted by March 4, 1996.
ADDRESSES : Comments on the 37th Report should be submitted to both the ITC and the TSCA Public Docket. Send one copy of written submissions to: John Walker, ITC Director, U.S. EPA (7401), 401 M St. SW., Washington, DC 20016. Send six copies of written submissions to: TSCA Public Docket Office (7407), Office of Pollution Prevention and Toxics, Environmental Protection Agency, Rm. B-607 NEM, 401 M St. SW., Washington, DC 20460. Submissions should bear the document control number (OPPTS–41044; FRL– 4991–6).

The public record supporting this action, including comments, is available for public inspection in Rm. B–607 NEM at the address noted above from 12:00 noon to 4 pm 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., Rm. ET– 543B,Washington, DC 20460, (202) 554– 1404, TDD (202) 554–0551.
SUPPLEMENTARY INFORMATION : EPA has received the TSCA Interagency Testing Committee’s 37th 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 Interagency Testing Committee (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. The most recent revisions to this List are included in the ITC’s 37th Report. The Report was received by the Administrator on November 22, 1995, and is included in this Notice. The Report recommends a group of 28 alkylphenols and alkylphenol ethoxylates, removes 43 silicone chemicals and 5 isocyanates previously recommended for testing and solicits use and exposure data for 9 High Production Volume Chemicals (HPVCs) and 10 isocyanates from the TSCA section 4(e) Priority Testing List

. II. Status of List

The ITC’s 37th Report requests use and exposure data for 9 HPVCs and 10 isocyanates, adds 28 chemicals to and removes 48 chemicals from the Priority Testing List. The current TSCA section 4(e) Priority Testing List contains 5 chemicals and 9 chemical groups; of these 3 chemical groups and 3 chemicals were designated for testing.

A notice will be published at a later date in the Federal Register adding certain of the substances recommended in the ITC’s 37th Report to the TSCA section 8(d) Health and Safety Data Reporting Rule (40 CFR Part 716), which requires the reporting of unpublished health and safety studies on the listed chemicals. That notice will also add some of the chemicals to the TSCA section 8(a) Preliminary Assessment Information Rule (40 CFR part 712). The section 8(a) rule requires the reporting of production volume, use, exposure, and release information on the listed chemicals.
III. Electronic and Oral Comments

The EPA invites interested persons to submit detailed comments on the ITC’s Report. A record has been established for this notice under docket number [OPPTS–41044]. A public version of this record including printed paper versions of electronic comments, which does not contain any information claimed as confidential business information (CBI), is available for inspection from 12 noon to 4 p.m., Monday through Friday, excluding legal holidays. The publicrecord is located in the TSCA Nonconfidential Information Center, Rm. NE–B607, 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

Electronic comments must be submitted as an ASCII file avoiding the use of special characters and any form of ecryption.

The official record for the 37th 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: January 22, 1996. Charles M. Auer, Director, Chemical Control Division, Office of Pollution Prevention and Toxics. Thirty-Seventh Report of the TSCA Interagency Testing Committee to the Administrator, U.S. Environmental Protection Agency Summary

This is the 37th 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 28 alkylphenols and alkylphenol ethoxylates and removing 43 previously-recommended silicone chemicals and 5 isocyanates. As noted in this Report, the ITC is

### 4189 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

soliciting use and exposure data for 9 of the 12 High Production Volume Chemicals that were recommended in its 36th Report (60 FR 42982, August 17, 1995) and consumer use and exposure data for the 10 isocyanates remaining on the List. 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.—T HE 

### TSCA S ECTION 

### 4( E 

### ) P RIORITY 

### T ESTING 

### L IST 

### (N OVEMBER 

### 1995)

Report Date Chemical/Group Action

26 May 1990

......... Isocyanates

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

................................................................ Recommended with intent-to-designate. 28 May 1991

......... Acetone

......................................................................... Designated. 28 May 1991

......... Thiophenol

.................................................................... Designated. 29 November 1991 10 Alkyl-, bromo-, chloro-, hydroxymethyl diaryl ethers Recommended. 30 May 1992

......... 13 Siloxanes

................................................................. Recommended. 31 January 1993

... 24 Chemicals with no dermal toxicity data

................... Designated. 32 May 1993

......... 32 Chemicals with insufficient dermal absorption data Designated. 34 May 1994

......... White phosphorus

......................................................... Designated. 34 May 1994

......... Ethyl tert-butyl ether

..................................................... Recommended. 34 May 1994

......... Tert-amyl methyl ether

.................................................. Recommended. 35 November 1994 24 Chemicals with insufficient dermal absorption data Designated. 36 May 1995

......... 12 High Production Volume Chemicals

........................ Recommended. 37 November 1995 28 Alkylphenols and alkylphenol ethoxylates

............... 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 36 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 membership and support personnel are listed at the end of this Report.

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. The 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’’ studies, ‘‘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

. II. 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.—R EVISIONS TO THE 

### TSCA S ECTION 

### 4( E 

### ) P RIORITY 

### T ESTING 

### L IST

CAS No. Chemical Name Action Date

Alkylphenols and alkylphenol ethoxylates Recommended

............................................................... 11/95 Butylphenols

. 88–18–6 2-tert-Butylphenol a 98–54–4 4-tert-Butylphenol a

. 99–71–8 4-sec-Butylphenol a

. 1638–22–8 4- n-Butylphenol b

. 3180–09–4 2-Butylphenol b

. 27178–34–3 tert-Butylphenol (mixed isomers) b
31195–95–6 Isobutylphenol (mixed isomers) b Pentylphenols
80–46–6 4-tert-Pentylphenol a 94–06–4 4-(1-Methylbutyl)phenol b
14938–35–3 4-Pentylphenol b

### 4190 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

TABLE 

### 2.—R EVISIONS TO THE 

### TSCA S ECTION 

### 4( E 

### ) P RIORITY 

### T ESTING 

### L IST

### —Continued

CAS No. Chemical Name Action Date

Octylphenols
949–13–3 2-Octylphenol b
1806–26–4 4-Octylphenol b
3884–95–5 2-(1,1,3,3-Tetramethylbutyl)phenol b
27193–28–8 (1,1,3,3-Tetramethylbutyl)phenol (mixed isomers) a,c

1322–69–6
29932–96–5
30105–54–5
62744–41–6
27985–70–2 (1-Methylheptyl)phenol (mixed isomers) b
54932–78–4 4-(2,2,3,3-Tetramethylbutyl)phenol b Nonylphenols
104–40–5 4-Nonylphenol b
11066–49–2 Isononylphenol (mixed isomers) b
17404–66–9 4-(1-Methyloctyl)phenol b
25154–52–3 Nonylphenol (mixed isomers) a,c

1300–16–9
84852–15–3 Branched 4-nonylphenol (mixed isomers) a Dodecylphenols
104–43–8 4-Dodecylphenol b
27193–86–8 Dodecylphenol (mixed isomers) a,c

1331–57–3 Octylphenol ethoxylates
2315–66–4 Decaethylene glycol 4-isooctylphenyl etherb
2497–58–7 Hexaethylene glycol 4-isooctylphenyl etherb
9002–93–1 Polyethylene glycol 4-(tert-octyl)phenyl etherb
9036–19–5 Polyethylene glycol mono(octyl)phenyl etherb
68987–90–6 Poly(oxy-1,2-ethanediyl), α-(octylphenyl)- ω-hydroxy-, branched a Silicone Chemicals Remove previously recommended chemicals 11/95
107–50–6 Tetradecamethylcyloheptasiloxane
107–52–8 Tetradecamethylhexasiloxane
107–53–9 Tetracosamethylundecasiloxane
541–01–5 Hexadecamethylheptasiloxane
541–05–9 Hexamethylcyclotrisiloxane
546–56–5 Octaphenylcyclotetrasiloxane
556–68–3 Hexadecamethylcyclooctasiloxane
556–69–4 Octadecamethyloctasiloxane
556–70–7 Docosamethyldecasiloxane
556–71–8 Octadecamethylcyclononasiloxane
999–97–3 Hexamethyldisilazane
2370–88–9 Tetramethylcyclotetrasiloxane
2374–14–3 Trifluoropropylmethylcyclotrisiloxane
2471–08–1 Hexacosamethyldodecasiloxane
2471–09–2 Octacosamethyltridecasiloxane
2471–10–5 Triacontamethyltetradecasiloxane
2471–11–6 Dotriacontmethylpentadecasiloxane
2554–06–5 Methylvinylcyclosiloxane
2627–95–4 Tetramethyldivinyldisiloxane
2652–13–3 Eicosamethylnonasiloxane

### 4191 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

TABLE 

### 2.—R EVISIONS TO THE 

### TSCA S ECTION 

### 4( E 

### ) P RIORITY 

### T ESTING 

### L IST

### —Continued

CAS No. Chemical Name Action Date

9004–73–3 Methylpolysiloxane
9006–65–9 Dimethicone
9016–00–6 Polydimethylsiloxane
18766–38–6 Docosamethylcycloundecasiloxane
18772–36–6 Eicosamethylcyclodecasiloxane
18844–04–7 Hexatriacontamethylheptadecasiloxane
18919–94–3 Tetracosamethylcyclododecasiloxane
23523–12–8 Hexatriacontamethylcyclooctadecasiloxane
23523–14–0 Triacontamethylcyclopentadecasiloxane
23732–94–7 Hexacosamethylcyclotridecasiloxane
36938–50–8 Tetratriacontamethylhexadecasiloxane
36938–52–0 Octatriacontamethyloctadecasiloxane
67762–94–1 Dimethylmethylvinylsiloxane
68037–59–2 Dimethylhydropolysiloxane
68607–75–0 Polymethyloctadecylsiloxane
115631–68–7 Siloxanes and silicones, dimethylmethyl 3,3,3- trifluoropropyl d
149050–40–8 Octacosamethylcyclotetradecasiloxane
150026–95–2 Dotriacontamethylcyclohexadecasiloxane
150026–96–3 Tetratriacontamethylcycloheptadecasiloxane
150026–97–4 Octatriacontamethylcyclononadecasiloxane
150026–98–5 Tetracontamethylcycloeicosasiloxane
150026–99–6 Tetracontamethylnonadecasiloxane
150027–00–2 Dotetracontamethyleicosasiloxane Isocyanates Remove previously recommended chemicals 11/95
102–36–3 3,4-Dichlorophenyl isocyanate
104–71–9 Phenyl isocyanate
104–12–1 p- Chlorophenyl isocyanate
111–36–4 n-Butyl isocyanate
3173–53–3 Cyclohexyl isocyanate

a Chemicals with production or importation volumes > 1 million pounds that are being considered for designation.
b Chemicals with production or importation volumes < 1 million pounds that are being recommended because they are structurally related to alkylphenols or alkylphenol ethoxylates being considered for designation.

c Alternate CAS numbers are listed for these chemicals.
d Listed as dimethylmethyltrifluoropropylsiloxane with no CAS number in ITC’s 30th Report (57 FR 30608, July 9, 1992).

III. Rationale for the Revisions A. ITC’s Activities During this Reporting Period

During the 6 months covered by this Report, the ITC evaluated several chemical groups. For alkylphenols and alkylphenol ethoxylates, 1989 and 1993 TSCA production and importation volume data were reviewed and online toxicology databases were searched. For silicone chemicals, unpublished chemistry, toxicology, use and exposure data were reviewed; these data were submitted in response to the ITC’s 30th Report (57 FR 30608, July 9, 1992). For the isocyanates recommended in the ITC’s 26th Report (55 FR 23050, June 5, 1990), published and unpublished toxicology, use and exposure data were reviewed. B. Specific Rationales

1. Recommended chemicals

— Alkylphenols and alkylphenol ethoxylates—Recommendation. Alkylphenols and alkylphenol ethoxylates are being added to the Priority Testing List to obtain unpublished TSCA section 8(d) studies and to determine if these studies meet U.S. Government data needs.

Rationale for recommendation. Alkylphenols and alkylphenol ethoxylates are being recommended to determine if there are unpublished studies that contain data to meet the needs of the Department of the Interior (DoI), the EPA and other U.S. Government organizations represented on the ITC. The ITC wants to review these unpublished data before determining if these chemicals should be designated for testing to meet U.S. Government data needs. Alkylphenols and alkylphenol ethoxylates are being recommended at this time because: (1) 1989 and 1993 TSCA production and importation volumes are in the multimillion pound range, (2) releases to the environment can occur through wastewater treatment systems and from agricultural runoff, (3) alkylphenol ethoxylates can degrade to alkylphenols, (4) alkylphenols can persist in the environment and be highly toxic to aquatic organisms and (5) exposure to

### 4192 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

alkylphenols and alkylphenol ethoxylates may result in estrogenic, reproductive or other adverse effects.

Supporting information. The Substructure-based Computerized Chemical Selection Expert System (SuCCSES ) is used to identify chemicals with shared substructures and associated health or ecological effects and similar TSCA production or importation volumes (Walker, Refs. 4 and 6). SuCCSES was used to identify the alkylphenols and alkylphenol ethoxylates listed in Table 2. As indicated in Table 2, nine of the alkylphenols and alkylphenol ethoxylates have 1989 and 1993 TSCA production and importation volumes greater than 1 million pounds and are being considered for designation. The ITC is listing alternate CAS numbers for some of these alkylphenols and alkylphenol ethoxylates to increase the possibility of retrieving a study because it is filed under a different CAS number. Table 2 also indicates that 19 alkylphenols and alkylphenol ethoxylates are being recommended because they are structurally related to those being considered for designation. Relevant data from these additional 19 chemicals will be used to predict or gain insight into the activity of the 9 alkylphenols and alkylphenol ethoxylates being considered for designation when no data are available for those 9 chemicals. The ITC is recommending structurally-related chemicals and alternate CAS-numbered chemicals to increase the possibility of obtaining unpublished studies on alkylphenols and alkylphenol ethoxylates that are related to those being considered for designation.

Existing U.S. Government data needs. The ITC has identified several data needs for alkylphenols and alkylphenol ethoxylates: (1) chemical composition (major components and impurities), (2) environmental fate of components and impurities and (3) health and ecological effects, including toxicokinetics and endocrine-modulating effects.

Completed activities of the ITC, EPA and alkylphenol manufacturers. The ITC is aware that for a few alkylphenols and alkylphenol ethoxylates there are numerous studies including those already developed under TSCA section 4 (Talmage, Ref. 3). The ITC is also aware that for some of these chemicals, few health effects, environmental fate and ecological effects data are available. The ITC reviews of butylphenols, pentylphenols, octylphenols, and nonylphenols suggested that these chemicals had potential to cause biological effects. Studies by Soto et al. (Ref. 2), White et al. (Ref. 10) and Purdom et al. (Ref. 1) suggest that alkylphenols and alkylphenolethoxylates may cause endocrinemodulating effects. Soto et al. (Ref. 2)reported that nonylphenol and 4-tertbutylphenol caused proliferation of human estrogen-sensitive MCF 7 breast tumor cells. White et al. (Ref. 10) reported that 4-octylphenol, 4- nonylphenol and 4-nonylphenol diethoxylate were capable of stimulating vitellogenin gene expression in trout hepatocytes. Vitellogenin is a protein synthesized by the liver of oviparous fish in response to stimulation by estradiol or estrogenic compounds. Purdom et al. (Ref. 1) suggested that alkylphenols or alkylphenol ethoxylates may have been responsible for elevated vitellogenin concentrations in fishexposed to effluents from 15 sewagetreatment works.

The ITC previously designated threealkylphenols for testing. 2-secButylphenol was designated in the 32nd Report (58 FR 38490, July 16, 1993). In response to this designation, the EPA solicited parties that would be interested in developing consent agreements for dermal absorption testing. The ITC designated 4-(1,1,3,3- tetramethylbutyl)phenol in its 11th Report (47 FR 54625, December 3, 1982) and 2,6-di-tert-butylphenol in its 18th Report (51 FR 18368, May 19, 1986). In response to these designations, the EPA implemented testing and the alkylphenol manufacturers developed the TSCA section 4 chemical fate and aquatic toxicity data. These data have been published (Walker, Refs. 5, 7, and 8).

The EPA has pursued testing for two other alkylphenols. The EPA published a TSCA section 4 notice proposing reproductive effects and developmental toxicity testing for dodecylphenol (56 FR 9092, March 4, 1991). The EPA worked with the alkylphenol manufacturers to develop chemical fate and aquatic toxicity data for branched 4- nonylphenol under a TSCA section 4 Enforceable Consent Agreement/Order (55 FR 5991, February 21, 1990). These data for branched 4-nonylphenol have been published (Walker, Ref. 8).

The TSCA section 8(d) rule that EPA promulgated for 2-sec-butylphenol did not require submission of ecological effects data (59 FR 5956, February 9, 1994). The ITC is recommending that the EPA amend this rule to require submission of ecological effects data in response to the data needs of the DoI and EPA. In response to the ITC’s designations of 4-(1,1,3,3-tetramethylbutyl)phenol and 2,6-di-tertbutylphenol, the EPA promulgated TSCA section 8(d) rules. The ITC will include studies that were submitted in response to these rules in its review of other unpublished studies that are submitted in response to the TSCA section 8(d) rules that the EPA will promulgate for the other alkylphenols or alkylphenol ethoxylates listed in Table 2. The ITC is not recommending these three alkylphenols because TSCA section 8(d) studies were previously submitted in response to these designations.

Related activities. The Organisation for Economic Cooperation and Development (OECD) has three of the recommended and two of the previously-designated alkylphenols in its Screening Information Data Sets (SIDS) program. The recommended alkylphenols with their sponsoring countries listed in parentheses are 4- tert-butylphenol (Japan), nonylphenol (mixed isomers) (United Kingdom and United States) and branched 4- nonylphenols (mixed isomers) (United Kingdom). The previously-designated alkylphenols are 4-(1,1,3,3-tetramethylbutyl)phenol and 2,6-di-tertbutylphenol (both the United States). The National Toxicology Program has scheduled branched 4-nonylphenols (mixed isomers) for a multigeneration reproductive effects and developmental toxicity test. The National Academy of Sciences is planning to review published data on hormone-related chemicals in the environment and alkylphenols is one chemical group for which they will be reviewing data. Industry convened the Endocrine Issues Coalition in 1995 to address scientific issues related to subtances in the environment that potentially may modulate the endocrine system. The CMA’s Alkylphenols and Ethoxylates Panel is a member of this Coalition.

2. Removal of chemicals from the Priority Testing List—a. Silicone chemicals. Fifty-six 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 (57 FR 30608, July 9, 1992). In response to this recommendation, the Silicones Environmental Health and Safety Council (SEHSC) met with the ITC and the EPA to discuss unpublished toxicity, use and exposure data. Most of the unpublished toxicity and exposure data were submitted in response to the TSCA section 8(d) reporting rule that was promulgated in response to the ITC’s 30th Report recommendations (58 FR 28511, May 15, 1993) and the technical amendments to that rule (58 FR 47647, September 10, 1993). All of the use data and some of the exposure data were submitted voluntarily to the

### 4193 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

ITC by the SEHSC. Interactions with the SEHSC facilitated information exchangeand data development for a previouslydesignated siloxane, octamethylcyclotetrasiloxane (Walker and Smock, Ref. 9). The SEHSC worked with the ITC and the EPA to develop a computerized system of physical properties, effects and use data for the 56 recommended silicone chemicals. The ITC has used the information in this system, the TSCA section 8(a) production and exposure data, and the information submitted voluntarily by the SEHSC to determine that, at this time, 43 of the previously-recommended silicone chemicals should be removed from the Priority Testing List (Table 2). The specific rationales for removing these chemicals are listed in the following Table 3.


### TABLE 

### 3.—P REVIOUSLY 

### R ECOMMENDED 

### S ILICONE 

### C HEMICALS 

### B EING 

### R EMOVED 

### F ROM THE 

### P RIORITY 

### T ESTING 

### L IST

CAS No. Chemical Name Removal rationale

999–97–3 Hexamethyldisilazane
9006–65–9 Dimethicone Highly reactive with moisture and therefore difficult to test for health effects
9016–00–6 Polydimethylsiloxane Highly reactive with moisture and therefore difficult to test for health effects
9004–73–3 Methylpolysiloxane
115631–68–7 Siloxanes and silicones, dimethylmethyl 3,3,3- trifluoropropyl a Synonyms for dimethyl silicones and siloxanes that remains on the Priority Testing List
67762–94–1 Dimethylmethylvinylsiloxane Site-limited intermediates used in the production of siloxane polymers
68037–59–2 Dimethylhydropolysiloxane Site-limited intermediates used in the production of siloxane polymers
68607–75–0 Polymethyloctadecylsiloxane Siloxane polymers that are consumed in their end use

546–56–5 Octaphenylcyclotetrasiloxane Siloxane that has no commercial sales or applications at this time
2370–88–9 Tetramethylcyclotetrasiloxane Siloxane that has no commercial sales or applications at this time
2374–14–3 Trifluoropropylmethylcyclotrisiloxane Siloxane that has no commercial sales or applications at this time
2554–06–5 Methylvinylcyclosiloxane Siloxane that has no commercial sales or applications at this time
2627–95–4 Tetramethyldivinyldisiloxane Siloxane that has no commercial sales or applications at this time Linear Siloxanes
107–52–8 Tetradecamethylhexasiloxane (L 6) b Siloxanes that are limited to industrial applications and transformed to polymers during processing
541–01–5 Hexadecamethylheptasiloxane (L7) Siloxanes that are limited to industrial applications and transformed to polymers during processing
556–69–4 Octadecamethyloctasiloxane (L 8) Siloxanes that are limited to industrial applications and transformed to polymers during processing
2652–13–3 Eicosamethylnonasiloxane (L9) Siloxanes that are limited to industrial applications and transformed to polymers during processing
556–70–7 Docosamethyldecasiloxane (L 10) Siloxanes that are limited to industrial applications and transformed to polymers during processing
107–53–9 Tetracosamethylundecasiloxane (L 11 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
2471–08–1 Hexacosamethyldodecasiloxane (L 12) Siloxanes that are limited to industrial applications and transformed to polymers during processing
2471–09–2 Octacosamethyltridecasiloxane (L 13 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
2471–10–5 Triacontamethyltetradecasiloxane (L 14) Siloxanes that are limited to industrial applications and transformed to polymers during processing
2471–11–6 Dotriacontmethylpentadecasiloxane (L 15 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
36938–50–8 Tetratriacontamethylhexadecasiloxane (L 16) Siloxanes that are limited to industrial applications and transformed to polymers during processing
18844–04–7 Hexatriacontamethylheptadecasiloxane (L 17) Siloxanes that are limited to industrial applications and transformed to polymers during processing
36938–52–0 Octatriacontamethyloctadecasiloxane (L 18) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150026–99–6 Tetracontamethylnonadecasiloxane (L 19) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150027–00–2 Dotetracontamethyleicosasiloxane (L20) Cyclic Siloxanes
541–05–9 Hexamethylcyclotrisiloxane (D 3 ) c Siloxanes that are limited to industrial applications and transformed to polymers during processing
107–50–6 Tetradecamethylcyloheptasiloxane (D 7) Siloxanes that are limited to industrial applications and transformed to polymers during processing

### 4194 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

TABLE 

### 3.—P REVIOUSLY 

### R ECOMMENDED 

### S ILICONE 

### C HEMICALS 

### B EING 

### R EMOVED 

### F ROM THE 

### P RIORITY 

### T ESTING 

### L IST



### — Continued

CAS No. Chemical Name Removal rationale

556–68–3 Hexadecamethylcyclooctasiloxane (D 8) Siloxanes that are limited to industrial applications and transformed to polymers during processing
556–71–8 Octadecamethylcyclononasiloxane (D 9) Siloxanes that are limited to industrial applications and transformed to polymers during processing
18772–36–6 Eicosamethylcyclodecasiloxane (D 10) Siloxanes that are limited to industrial applications and transformed to polymers during processing
18766–38–6 Docosamethylcycloundecasiloxane (D 11 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
18919–94–3 Tetracosamethylcyclododecasiloxane (D 12) Siloxanes that are limited to industrial applications and transformed to polymers during processing
23732–94–7 Hexacosamethylcyclotridecasiloxane (D 13 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
149050–40–8 Octacosamethylcyclotetradecasiloxane (D 14) Siloxanes that are limited to industrial applications and transformed to polymers during processing
23523–14–0 Triacontamethylcyclopentadecasiloxane (D 15 ) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150026–95–2 Dotriacontamethylcyclohexadecasiloxane (D 16) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150026–96–3 Tetratriacontamethylcycloheptadecasiloxane (D 17) Siloxanes that are limited to industrial applications and transformed to polymers during processing
23523–12–8 Hexatriacontamethylcyclooctadecasiloxane (D 18) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150026–97–4 Octatriacontamethylcyclononadecasiloxane (D 19) Siloxanes that are limited to industrial applications and transformed to polymers during processing
150026–98–5 Tetracontamethylcycloeicosasiloxane (D 20) Siloxanes that are non-isolated components of dimethyl siloxanes

a Listed as dimethylmethyltrifluoropropylsiloxane with no CAS number in ITC’s 30th Report (57 FR 30608, July 9, 1992).
b L followed by a number refers to the number of repeating dimethyl siloxanes in a linear chain.

c D followed by a number refers to the number of repeating dimethyl siloxanes in a cyclic chain.

There are 13 siloxanes remaining on the Priority Testing List as shown in the following Table 4:


### TABLE 

### 4.—S ILOXANES REMAINING ON THE 

### P RIORITY 

### T ESTING 

### L IST

CAS No. Chemical Name

Cyclic Siloxanes
556–67–2 Octamethylcyclotetrasiloxane (D 4)
541–02–6 Decamethylcyclopentasiloxane (D 5 )
540–97–6 Dodecamethylcyclohexasiloxane (D 6)
69430–24–6 Cyclopolydimethylsiloxane (D x) Linear Siloxanes

107–46–0 Hexamethyldisiloxane (L2)
107–51–7 Octamethyltrisiloxane (L 3 )
141–62–8 Decamethyltetrasiloxane (L4)
141–63–9 Dodecamethylpentasiloxane (L5 ) Phenyl Siloxanes
68083–14–7 Dimethyldiphenylsiloxane a Polymers
63148–62–9 Dimethyl silicones and siloxanes a

9006–65–9
9016–00–6
67762–90–7 Dimethyl silicones and siloxanes, reaction products with silica
68037–74–1 Dimethylmonomethylpolysiloxanes

### 4195 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

TABLE 

### 4.—S ILOXANES REMAINING ON THE 

### P RIORITY 

### T ESTING 

### L IST

### —Continued

CAS No. Chemical Name

70131–67–8 Dimethyl silicones and siloxanes hydroxy terminated

aAlternate CAS numbers are listed for this chemical.

b. Isocyanates. In its 26th Report, the ITC recommended a group of 43 isocyanates for physical and chemical property testing in response to a nomination from the EPA to support its TSCA New Chemicals Program (55 FR 23050, June 5, 1990). The ITC removed 28 of these isocyanates from the Priority Testing List in its 35th Report 59 FR 67596, December 29, 1994). The ITC is removing 5 more isocyanates from the List in this Report (Table 2). 3,4- Dichlorophenyl isocyanate and pchlorophenyl isocyanate are being removed because 1993 production volumes were less than 10,000 pounds. Phenyl isocyanate is being removed because 1993 production volumes were less than 1,000,000 pounds and there are no currently identified U.S. Government data needs. n- Butyl isocyanate and cyclohexyl isocyanate are being removed because there are no currently identified U.S. Government data needs. IV. Activities Related to PreviouslyRecommended Chemicals A. High Production Volume Chemicals

The ITC solicited use and exposure data for 12 High Production Volume Chemicals (HPVCs) in its 36th report (60 FR 42982, August 17, 1995) and suggested a 60–day submission deadline from the FR publication date (October 17, 1995). In response to that solicitation, the ITC received a September 15, 1995, submission from Eastman Chemical Company for diethylene glycol monoethyl ether acetate (CAS No. 112–15–2), a September 19, 1995, offer from the Zeneca Corporation to provide use and exposure data for trichloromethane sulfenyl chloride (CAS No. 594–42–3) and an October 12, 1995, submission from Ferro Corporation for diethylene glycol dimethyl ether (CAS No. 111–96– 6). The ITC will review the use and exposure data for these three HPVCs. The ITC appreciates these timely responses and encourages the manufacturers, processors, and users of the other nine HPVCs to contact the ITC with offers to provide use and exposure data. B. Isocyanates

The ITC is soliciting consumer use data for the nine diisocyanates remaining on the Priority Testing List (Table 5). The data are being solicited to address the information needs of the Consumer Product Safety Commission (CPSC). For several of these isocyanates, the ITC is continuing its review of exposure, health effects and chemical fate information, including information based on structure-activity relationships (SARs), in response to concerns of the Department of Defense (DoD) and the EPA.

In its 26th Report, the ITC recommended a group of 43 isocyanates for physical and chemical property testing in response to a nomination from the EPA to support its TSCA New Chemicals Program (55 FR 23050, June 5, 1990). As noted above in section III(B)(2)(b) of this ITC Report, 33 of these isocyanates have been removed from the Priority Testing List. The 10 remaining isocyanates are listed in the following Table 5.


### TABLE 

### 5.—I SOCYANATES 

### R EMAINING ON THE 

### P RIORITY 

### T ESTING 

### L IST

CAS No. Chemical Name

Monoisocyanate
329–01–1 ( α,α,α-Trifluoro- m- tolyl)isocyanate Diisocyanates
91–08–7 2,6-Toluene diisocyanate (2,6-TDI)
101–68–8 4,4′-Diphenylmethane diisocyanate (MDI)
584–84–9 2,4-Toluene diisocyanate (2,4-TDI)
4035–89–6 Tris(isocyanatohexyl)biuret
4098–71–9 Isophorone diisocyanate
5124–30–1 1,1’-Methylenebis(4-isocyanatocyclohexane)
5873–54–1 1-Isocyanato-2-((4-isocyanatophenyl)methyl)benzene
26447–40–5 1,1’-Methylenebis(isocyanatobenzene)
26471–62–5 Toluene diisocyanate (80% 2,4-TDI; 20% 2,6-TDI)

For these 10 isocyanates, the ITC is reviewing data on 1993 TSCA production and importation volumes, as well as published and unpublished (TSCA section 8(d), 8(e), FYI, etc.) data on physical and chemical properties, environmental fate and releases, health effects, occupational exposures and uses. For each of these isocyanates, the ITC is monitoring ongoing testing, including any testing that might be considered by the International Isocyanates Institute, the CMA or the OECD. At this time, the ITC has determined that there are insufficient consumer use and exposure data to permit an accurate assessment of exposure or the need for additional testing of the diisocyanates listed in Table 5. The ITC is soliciting consumer use data on these as well as

### 4196 Federal Register / Vol. 61, No. 23 / Friday, February 2, 1996 / Notices

any other commercially relevant diisocyanates (e.g., hexamethylene diisocyanate, CAS No. 822–06–0). Information on the presence of diisocyanates in commercially available products is needed as well as information on exposures that result from their use. The following specific information is solicited:

• Category of products in which diisocyanates (all forms) are present, such as rigid and flexible foams, coatings, and adhesives

• Specific diisocyanate present, by product category

• Chemical form of the diisocyanate (monomer, prepolymer, oligomer, polymer, etc.)

• Weight fraction of diisocyanate in the product and the relative amount of the different diisocyanate forms, particularly free monomer, oligomer, and prepolymer (a rough range of weight fraction is sufficient)

• Percent of total manufactured/ imported volume (rough estimate is sufficient)

• Form of the product (liquid, aerosol, foam, etc.)

• General application of the product (sealant, paint, adhesive, insulation, etc.)

• Air monitoring or exposure simulation data for diisocyanates resulting from use of any of the indicated product categories
References

(1) Purdom, C.E., Hardiman, P.A., Bye, V.J., Eno, N.C., Tyler, C.R., and Sumpter, J.P. Estrogenic effects of effluents from sewage treatments works. Chemical Ecology . 8:275– 285 (1994).

(2) Soto, A.M., Justicia, H., Wray, J.W., and Sonnenschein, C. p- Nonylphenol: an estrogenic xenobiotic released from ‘‘modified’’ polystyrene. Environmental Health Perspectives. 92:167–173 (1991).

(3) Talmage, S.S. Environmental and human safety of major surfactants: Alcohol ethoxylates and alkylphenol ethoxylates. A report to the Soap and Detergent Association. Lewis Publishers, Boca Raton, FL (1994), 374pp.

(4) Walker, J.D. Chemical selection by the TSCA Interagency Testing Committee: Use of computerized substructure searching to identify chemical groups for health effects, chemical fate and ecological effects testing. Sci. Total Environ. 109/110:691–700 (1991). (5) Walker, J.D. Review of ecological effects and bioconcentration testing recommended by the TSCA Interagency Testing Committee and implemented by EPA under the Toxic Substances Control Act: Chemicals, tests and methods. pp. 92–115. In W.G. Landis, J.S. Hughes and M.A. Lewis (eds.), Environmental Toxicology and Risk Assessment, ASTM STP 1179. ASTM, Philadelphia, PA (1993).

(6) Walker, J.D. Estimation Methods Used by the TSCA Interagency Testing Committee to Prioritize Chemicals for Testing: Exposure and Biological Effects Scoring and Structure Activity Relationships. Toxicol. Model

. 1:123–141 (1995a).

(7) Walker, J.D. Testing Decisions of the TSCA Interagency Testing Committee for Chemicals on Canada’s Domestic SubstancesList and Priority Substances List: Di-tertbutylphenol, ethyl benzene, brominated flame retardants, phthalate esters, chloroparaffins, chlorinated benzenes and anilines. In T.W. LaPoint, F.T. Price, and E.E. Little (eds), Environmental Toxicology and Risk Assessment: Fourth Volume, ASTM STP 1262, ASTM, Philadelphia. In Press (1995b).

(8) Walker, J.D. Recommendations of the TSCA Interagency Testing Committee: Aquatic toxicity, bioconcentration and chemical fate data developed under section 4 of the Toxic Substances Control Act. pp. 669–701. In G.M. Rand (ed), Fundamentals of Aquatic Toxicology II, Taylor Francis Publishers, Washington, DC (1995c).

(9) Walker, J.D. and W.H. Smock. Chemicals recommended for testing by the TSCA Interagency Testing Committee: A case study of octamethylcyclotetrasiloxane. Environmental Toxicology and Chemistry 14:1631–1634 (1995).

(10) White, R., Jobling, S., Hoare, S.A., Sumpter, J.P., and Parker, M.G. Environmentally persistent alkylphenol compounds are estrogenic. Endocrinology 135:175–182 (1994). TSCA Interagency Testing Committee Statutory Organizations and Their Representatives

Council on Environmental Quality Brad Campbell, Member Department of Commerce Edward White, Member Environmental Protection Agency David R. Williams, Member Lois Dicker, Alternate
National Cancer Institute Victor Fung, Member Harry Seifried, Alternate National Institute of Environmental Health Sciences Errol Zeiger, Member, Chair H. B. Matthews, Alternate National Institute for Occupational Safety and Health Henryka Nagy, Member 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, Vice Chair 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, Ph.D, M.P.H., 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. 96–1721 Filed 2–1–96; 8:45 am]

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