[Federal Register Volume 62, Number 37 (Tuesday, February 25, 1997)]
[Notices]
[Pages 8578-8583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4620]



[[Page 8577]]

_______________________________________________________________________

Part III





Environmental Protection Agency





_______________________________________________________________________



Thirty-Ninth Report of the Interagency Testing Committee to the 
Administrator; Receipt of Report, Request for Comments; Notice

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

[[Page 8578]]



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 Thirty-Ninth ITC Report should be 
received by March 27, 1997.

ADDRESSES: Comments on the Thirty-Ninth 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: [email protected] or to the EPA at: 
[email protected]. 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 Non-Confidential 
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 re-examined 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 CAS-numbered 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 Non-
Confidential 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: [email protected] and to the 
EPA at: [email protected].

[[Page 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       Designated             
                                                                 Confidence RfD                                 
                                                                Acetone                                         
                                                                Thiophenol                                      
29...................................  November 1991            10 Alkyl-, bromo-,       Recommended            
                                                                 chloro-, hydroxymethyl                         
                                                                 diaryl ethers                                  
30...................................  May 1992                 8 Siloxanes              Recommended            
31...................................  January 1993             24 Chemicals with        Designated             
                                                                 insufficient dermal                            
                                                                 absorption rate data                           
32...................................  May 1993                 32 Chemicals with        Designated             
                                                                 insufficient dermal                            
                                                                 absorption rate data                           
35...................................  November 1994            24 Chemicals with        Designated             
                                                                 insufficient dermal                            
                                                                 absorption rate data                           
36...................................  May 1995                 10 High Production       Recommended            
                                                                 Volume Chemicals                               
                                                                 (HPVCs)                                        
37...................................  November 1995            28 Alkylphenols and      Recommended            
                                                                 Ethoxylates                                    
39...................................  November 1996            23 Nonylphenol           Recommended            
                                                                 Ethoxylates                                    
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

[[Page 8580]]

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.-                                                   
                                       hydroxy-                                                                 
20427-84-3..........................  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.-                                                    
                                       hydroxy-                                                                 
26264-02-8..........................  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.-hydroxy-                                                         
51938-25-1..........................  Poly(oxy-1,2-                                                             
                                       ethanediyl), .alpha.-(2-                                                 
                                       nonylphenyl)-.omega.-                                                    
                                       hydroxy-                                                                 
65455-72-3..........................  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        11/96                  
                                                                 Recommended chemicals                          
69430-24-6..........................  Cyclopolydimethylsiloxan                                                  
                                       e (Dx)                                                                   
68083-14-7..........................  Dimethyl, diphenyl                                                        
                                       siloxanes and silicones                                                  
67762-90-7..........................  Dimethyl silicones and                                                    
                                       siloxanes, reaction                                                      
                                       products with silica                                                     
68037-74-1..........................  Dimethylmonomethylpolysi                                                  
                                       loxanes                                                                  
70131-67-8..........................  Dimethyl silicones and                                                    
                                       siloxanes hydroxy                                                        
                                       terminated                                                               
----------------------------------------------------------------------------------------------------------------
aNot Assigned.                                                                                                  


[[Page 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 previously-promulgated 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-p-dioxin 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

[[Page 8582]]

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. Twenty-
three (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 CAS-numbered 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...................  Cyclopolydimeth  Toxicity of             
                                ylsiloxane       cyclopolydimethylsiloxa
                                (Dx)             ne is likely to be     
                                                 predicted from testing 
                                                 octamethylcyclotetrasil
                                                 oxane (D4),            
                                                 decamethylcyclopentasil
                                                 oxane (D5) and         
                                                 dodecamethylcyclohexasi
                                                 loxane (D6) (see Table 
                                                 4).                    
                                                 Cyclopolydimethylsiloxa
                                                 ne is used only as a   
                                                 site-limited           
                                                 intermediate to        
                                                 manufacture D4, D5 and 
                                                 D6.                    
68083-14-7...................  Dimethyl,        Low exposure potential  
                                diphenyl         based on annual        
                                siloxanes and    production volume and  
                                silicones        specialized uses.      
67762-90-7...................  Dimethyl          Toxicity of siloxane   
                                silicones and    polymers bearing CAS   
                                siloxanes,       numbers 67762-90-7,    
                                reaction         68037-74-1 and 70131-67-
                                products with    8 is likely to be      
                                silica           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...................  Dimethylmonomet  Toxicity of siloxane    
                                hylpolysiloxan   polymers bearing CAS   
                                es               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         Toxicity of siloxane    
                                silicones and    polymers bearing CAS   
                                siloxanes        numbers 67762-90-7,    
                                hydroxy          68037-74-1 and 70131-67-
                                terminated       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)                       
  540-97-6................................  Dodecamethylcyclohexasiloxan
                                             e (D6)                     
Linear Siloxanes..........................                              
  107-46-0................................  Hexamethyldisiloxane (L2)   
  107-51-7................................  Octamethyltrisiloxane (L3)  
  141-62-8................................  Decamethyltetrasiloxane (L4)
  141-63-9................................  Dodecamethylpentasiloxane   
                                             (L5)                       
Polymers..................................                              
  63148-62-9..............................  Dimethyl silicones and      
                                             siloxanes                  
  9006-65-9a..............................                              
  9016-00-6a .............................                              
------------------------------------------------------------------------
aAlternate CAS numbers are listed for this chemical.                    


[[Page 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:[email protected]

[FR Doc. 97-4620 Filed 2-24-97; 8:45 am]
BILLING CODE 6560-50-F