[Federal Register Volume 60, Number 55 (Wednesday, March 22, 1995)]
[Notices]
[Pages 15143-15145]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-7060]



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ENVIRONMENTAL PROTECTION AGENCY
[OPPTS-42182; FRL-4943-6]


Certain Paint Stripping Chemicals; Solicitation of Testing 
Proposals for Negotiation of TSCA Section 4 Enforceable Consent 
Agreements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: This notice invites manufacturers and processors of certain 
chemical substances used in commercial paint strippers and other 
interested parties to develop and submit to EPA specific toxicity 
testing proposals for these chemicals. Testing is needed for three 
dibasic esters (DBEs), specifically, dimethyl adipate, dimethyl 
glutarate and dimethyl succinate. The EPA, the Consumer Product Safety 
Commission and the National Toxicology Program have consulted on the 
need for and nature of toxicity testing of DBEs, and the means for 
implementing such testing.

DATES: Written testing proposals must be received by May 22, 1995. EPA 
may extend the deadline for receipt of testing proposals upon a showing 
of good faith efforts to develop testing proposals by the initial 
deadline.

ADDRESSES: Submit three copies of written testing proposals to TSCA 
Docket Receipts (7407), Office of Pollution Prevention and Toxics, 
Environmental Protection Agency, Rm. G-99, East Tower, 401 M St., SW., 
Washington, DC 20460. Submissions should bear the document control 
number (OPPTS-42182; FRL-4943-6). The public docket supporting this 
action, including comments, is available for public inspection in the 
Nonconfidential Information Center, Rm NE-B607, at the above address 
from 12 noon to 4 p.m., Monday through Friday, except legal holidays.

FOR FURTHER INFORMATION CONTACT: James Willis, Acting Director, 
Environmental Assistance Division (7408), Rm. E543B, 401 M St., SW., 
Washington, DC 20460, (202) 554-1404, TDD (202) 554-0551. For specific 
information regarding this action or related activities, contact George 
Semeniuk, Project Manager, Chemical Testing and Information Branch 
(7405), Rm E221B, 401 M St., SW., Washington, DC 20460, (202) 260-2134.

SUPPLEMENTARY INFORMATION:

I. Background

A. Rationale for Action

    Known as dibasic esters (DBEs), dimethyl adipate (DMA, CAS No. 627-
93-0), dimethyl glutarate (DMG, CAS No. 1119-40-0) and dimethyl 
succinate (DMS, CAS No. 106-65-0) are component chemicals of solvent 
mixtures used in paint stripping formulations that are sold to the 
general public. Consumers can be significantly exposed to DBEs during 
use of these formulations. This potential for significant exposure, a 
reported adverse human effect--blurred vision--resulting from the use 
of DBE-based paint strippers, and the results of limited toxicity 
testing (rats), form the [[Page 15144]] foundation for the Agency's 
concern for the potential health risk that may be posed to consumers by 
DBE-based paint strippers. Upon further review of the other chemicals 
being used in commercial paint strippers, the Agency may determine that 
other commercial paint stripper chemicals in addition to the DBEs may 
pose significant exposures and possible risks to consumers or to other 
users. It may then seek additional testing, if necessary, to evaluate 
more fully that risk, in conjunction with, or apart from, the testing 
of the DBEs.
    EPA's Office of Pollution Prevention and Toxics (OPPT) administers 
the Toxic Substances Control Act (TSCA) and the TSCA section 4 testing 
program. Under TSCA section 4, 15 U.S.C. 2603, EPA may require that 
chemical manufacturers and processors provide to EPA test data that can 
be used to assess the impact on human health and the environment from 
exposure to such chemicals. In addition to imposing section 4 testing 
requirements by rulemaking, OPPT has developed an Enforceable Consent 
Agreement (ECA) process for obtaining needed testing often with less 
time and resources and more flexibility than under a test rule. See 40 
CFR part 790. On numerous occasions, chemical companies have approached 
EPA to negotiate ECAs for chemicals which are likely to become the 
subject of proposed test rules.
    Testing proposals for the DBEs should cover all identified data 
needs of the substances in order to be considered for ECA negotiation. 
If, after receiving testing proposals, EPA pursues negotiations for one 
or more ECAs applicable to these chemicals, EPA will, through a notice 
in the Federal Register, solicit requests by individuals to be 
designated an interested party to the negotiation(s). EPA has authority 
to require testing for these chemical substances under section 4 of the 
Toxic Substances Control Act (TSCA)(15 U.S.C. 2601-2692) and, if an 
ECA-based approach does not prove viable, EPA would proceed with 
proposed rulemaking to require the needed testing.

B. Chemical Data Needs

    In 1986, the Consumer Product Safety Commission (CPSC) established 
a labeling and enforcement policy for methylene chloride, a chemical 
solvent used in many paint strippers and household products and 
considered hazardous due to its potential carcinogenicity. Use of such 
products often resulted in widespread and significant consumer 
exposure. Since then, paint strippers that do not contain methylene 
chloride have been developed and marketed to consumers as ``safe 
alternatives'' to the methylene chloride-based formulations. Mixtures, 
or blends, of dibasic esters (DBEs) are becoming an important 
substitute solvent in alternative paint stripper formulations.
    There is limited toxicity information available on the individual 
DBEs and the alternative paint stripper formulations that use DBEs. An 
adverse human health effect--blurred vision--has been reported for a 
user who used DBE-based paint strippers in a poorly ventilated setting. 
This response was associated with DBE-based paint strippers that 
contained high percentages of the more volatile DMG and DMS and less 
than 20 percent DMA.
    A well-designed and executed battery of tests was carried out by 
the E.I. Du Pont de Nemours Company to evaluate the effects of a 
mixture of DBEs on experimental animals. These tests included a single-
dose acute study, a 2-week subacute study, two separate subchronic 
studies, a reproductive toxicity study (one-generation), and a 
developmental toxicity study. The studies utilized male and female rats 
that were exposed via inhalation of vapor or vapor aerosols of a DBE 
blend that contained 66 percent DMG, 17 percent DMA and 17 percent DMS. 
Among other findings, these studies established the lethal 
concentration from a 4-hour exposure to be approximately 4,000 mg/
m-3. Subchronic inhalation studies demonstrated that DBE could 
produce, depending upon the exposure concentration, progressive 
degeneration of the nasal olfactory epithelium, a dose-dependent 
decrease in liver weight, a depression in serum sodium levels and, at 
high exposure concentrations, a reduction in body weight. In addition, 
studies of the effects of DBE exposure on reproduction showed decreases 
in parental and pup weight gain and an increased incidence of delayed 
renal papilla development. One test animal developed a tumor (meningeal 
sarcoma) on the olfactory bulb of the brain. Results from the 
developmental toxicity study revealed significant reductions in body 
weight gain and food consumption for female rats exposed at higher 
concentrations and significant increases in percent of litters having 
one or more malformed fetuses. The deposition and metabolism of DBE 
vapors in the upper respiratory tract of rats has also been studied by 
DuPont researchers and yielded insight into understanding DBE-induced 
degeneration of the olfactory epithelium in test animals and the 
potential for similar effects in humans.
    An EPA-led interagency workgroup composed of representatives from 
EPA and CPSC was formed in 1993 to: (1) assess the human health risks 
posed by the myriad chemical substances (or ``cluster of chemicals'') 
used in paint stripper formulations sold to consumers and (2) identify 
potential options for reducing risk. CPSC identified a need to develop 
test data on DMA that would provide a more complete toxicity profile 
that would be used in comparing DMA's hazards to that of methylene 
chloride and other paint stripping chemicals. In 1994, CPSC formally 
nominated DMA as its 1994 priority chemical for federally-funded 
testing under the National Toxicology Program (NTP) and described an 
array of tests that would meet its needs. The testing that CPSC 
requested for DMA concerned the following effects: oncogenicity and 
genotoxicity, sensory irritation, toxicity following subchronic dermal 
administration, reproductive and developmental toxicity in a mammalian 
species other than the rat, neurotoxicity (screening), and in vitro 
metabolism/toxicity using human upper respiratory tissue.
    In December, 1994, the Executive Committee of the NTP convened and 
decided to refer the bulk of the testing requested by CPSC to EPA for 
implementation using TSCA testing authorities. This decision was taken 
because of the commercial significance of DMA, TSCA's stated policy 
that testing is the responsibility of industry (15 U.S.C. 2601), and 
EPA's interest in collecting needed data on the broader class of DBEs 
currently used in paint strippers. However, testing will be conducted 
by NTP for each of the three DBEs with regard to genotoxicity (the 
Salmonella typhimurium reverse mutation assay and the in vivo mammalian 
bone marrow cytogenetic test: micronucleus assay).
    The testing regime identified by CPSC for DMA is comparable to that 
recently undertaken for N-methylpyrrolidone under an ECA published in 
the Federal Register of November 23, 1993 (58 FR 61814). EPA believes, 
however, that testing that is similar, or complementary, to that 
specified for DMA is also needed for DMG and DMS in order to compare 
and contrast the toxicities of all three chemical substances. When used 
in paint stripper formulations, all three DBEs are usually present, 
although their relative proportions may vary among commercial 
formulations.
    After consultation, EPA and CPSC have agreed that the 2-tier 
testing [[Page 15145]] regime identified in Table 1 below is both 
appropriate and needed for the individual DBEs. As a matter of policy, 
EPA believes testing of the individual components is preferable to 
testing mixtures of the DBEs, although EPA would consider favorably a 
testing regime for the DBEs that included mixture testing, provided the 
individual components were also tested. EPA also invites the submission 
of additional testing proposals (beyond the testing described in the 
following Table 1) that address inter-species differences in 
metabolism, dosimetry or mode of toxic action for use in improving the 
extrapolation of DBE-induced toxicity in animal experiments to adverse 
effects that may occur in humans at relevant exposure levels.

                        Table 1.--Proposed Testing and Test Standards for Individual DBEs                       
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                              Species             Exposure route         Test duration        Guidelines/notes  
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        Tier 1                                                                                                  
         Testing                                                                                                
1.1 In vitro Gene      NA...................  NA...................  NA...................  40 CFR 798.5300.    
 mutation in                                                                                                    
 mammalian cells                                                                                                
 (DMA, DMG & DMS).                                                                                              
                                                                                                                
1.2 SIDS Reproductive  Mouse................  Inhalation for most    45 days..............  OECD\1\ Guideline   
 toxicity Screening                            volatile DBE; dermal                          for SIDS Testing   
 (DMA, DMG & DMS).                             for other two..                               No. 422 ``Combined 
                                                                                             Repeated Dose      
                                                                                             Toxicity Study with
                                                                                             the Reproduction/  
                                                                                             Developmental      
                                                                                             Toxicity Screening 
                                                                                             Test 1994.''       
                                                                                                                
1.3 Sensory            Mouse................  Inhalation...........  NA...................  ASTM E981-84        
 irritation (DMA, DMG                                                                        standard test      
 & DMS).                                                                                     method.            
                                                                                                                
        Tier 2                                                                                                  
         Testing\2\                                                                                             
2.1 Two generation     Mouse or rat.........  To be selected based   2 generation.........  40 CFR 798.4700, as 
 reproductive study                            on Tier 1 results..                           proposed for       
 (DMA, DMG or DMS).                                                                          revision (59 FR    
                                                                                             42272, August 17,  
                                                                                             1994).             
                                                                                                                
2.2 Subchronic         Rat..................  To be selected based   90 days..............  1991 Neurotoxicity  
 neurotoxicity (DMA,                           on Tier 1 results..                           Testing Guidelines.
 DMG or DMS).                                                                                Unless 2-generation
                                                                                             reproductive study 
                                                                                             is run using the   
                                                                                             rat, this testing  
                                                                                             will require a     
                                                                                             second 90-day      
                                                                                             study.             
                                                                                                                
2.3 Developmental      2 species: mouse or    To be selected based   NA...................  40 CFR 798.4900, as 
 toxicity study (DMA,   rat, and rabbit.       on Tier 1 results..                           proposed for       
 DMG or DMS).                                                                                revision (59 FR    
                                                                                             42272, August 17,  
                                                                                             1994).             
                                                                                                                
2.4 Oncogenicity       Mouse and rat........  To be selected based   2 years +............  40 CFR 798.3300     
 studies (DMA, DMG or                          on Tier 1 results..                                              
 DMS).                                                                                                          
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\1\Organization of Economic Cooperation and Development, Paris, France.                                         
\2\Tier 2 testing will be done on one of the three DBEs selected on the basis of available toxicity data and    
  exposure potential, as appropriate.                                                                           

II. Public Docket

    EPA has established a docket for this action (docket control number 
OPPTS-42182; FRL-4943-6). The docket contains basic information 
considered by EPA in developing this action and includes:
    1. Letter from Marilyn L. Wind, Ph.D., Director of Poison 
Prevention and Scientific Coordination, Consumer Product Safety 
Commission to Dr. Errol Zeiger, National Toxicology Program, National 
Institute for Environmental Health Sciences, January 31, 1994. (Copies 
of unpublished material cited in the letter are included in the docket. 
Within 15 days of publication of this notice, the Agency expects to add 
the published material cited in the letter to the docket.)
    2. 1991 Neurotoxicology Testing Guidelines.
    3. OPPTS Health Effects Test Guidelines for reproductive and 
fertility effects (OPPTS 870.3800).
    4. OPPTS Health Effects Test Guidelines for developmental toxicity 
(OPPTS 870.3700).
    EPA will supplement the docket with additional information as it is 
received.
    A public version of this docket is available in the TSCA Non-
confidential Information Center (NCIC) from 12 noon to 4 p.m., Monday 
through Friday, except legal holidays. The NCIC is located in Rm NE-
B607, Mail Code 7407, 401 M St., SW., Washington, DC 20460. Written 
requests for copies of documents contained in this docket may be sent 
to the above address or faxed to (202) 260-9555.

    Authority: 15 U.S.C. 2603.

    Dated: March 16, 1995.

Charles M. Auer,
Director, Chemical Control Division, Office of Pollution Prevention and 
Toxics.

[FR Doc. 95-7060 Filed 3-21-95; 8:45 am]
BILLING CODE 6560-50-F