[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
