Document r6E1xVExN79j6kMdx1qGMNwOe

tar 1HB*1 CHtMIM ACCOMPLISHMENTS: The Panel completed a Screening Information Data Set (SIDS) Dossier of available data on TCIP and submitted a SIAR to EPA. The SIAR was reviewed at the May 1996 OECD SIDS Initial Assessment Meeting (SIAM 4). OECD was in agreement with EPA that TCIP was of low priority for further work. The chemical, along with eight other Tris(chloroalkyl)phosphates previously listed with Intent-to-Designate by the InteragencyTesting Commit tee (ITC), was removed from the list in the 36th ITC Report. PLANS:. The Panel will address the few OECD com ments on the TCIP SIAR and submit the final report to EPA for distribution through OECD. Substances Control Act (TSCA), Section 4, EPA pro posed neurotoxicity studies as well as developmental and reproductive toxicity testing to fill the data gaps identi fied by ATSDR. The Committee considered the pro posed studies excessive in meeting ATSDR's mandate and negotiated an alternative cost-effective research program that would meet the Agency' objectives. As a result of the successful negotiation, EPA will not issue a TSCA Section 4 rule for the proposed studies. The Committee also agreed to fund a molecular research program to study vinyl chloride genotoxicity as a complement to the combined reproductive and devel opmental toxicity studies. The molecular study will pro vide information relevant to cancer risk assessment of vinyl chloride and vasdy improve understanding of the mechanisms of vinyl chloride carcinogenesis. Vinyl Chloride Panel: Health The Panel wasformed in 1971 by vinylchloride manufac turers to develop and assess health and safety data on vinyl chloride monomer. ACCOMPLISHMENTS: The Vinyl Chloride Panel Health Committee submitted comments to the Agency for Toxic Substances and Disease Registry (ATSDR) on the draft ToxicologicalProfilefor Vinyl Chloride. The Committee recommended full consideration ofa physi ologically-based pharmacokinetic (PBPK) model to assess risk. The Committee successfully negotiated a testing pro gram with ATSDR that includes conducting a com bined inhalation two-generation reproductive and de velopmental toxicity study in rats. Under the Toxic The Committee also submitted comments to ATSDR on the proposed MedicalManagement Guidelinesfir Vi nyl Chloride. The Committee suggested specific changes in document language to read more clearly and accu rately from scientific and medical standpoints. Changes were suggested for sections on acute and chronic expo sure; developmental, reproductive and other health ef fects, and; route of exposure. In addition, the Com mittee suggested adding a section on occupational ex posure. In response to an EPA pilot project to update the Inte grated Risk Information System (IRIS) entry for vinyl chloride, the Committee submitted an inventory of pertinent scientific literature to EPA's National Center for Environmental Assessment (NCEA). The Com mittee also informed NCEA officials of relevant ongo ing research efforts which it sponsors. IRIS is the pri mary vehicle for communication of health hazard as sessments by EPA scientists. It is used by other federal agencies and some states as a guide in implementing regulations such as the Clean Air Act, the Clean Wa- CMA 114997 A *1! CHEMSmit ter Act, Superfund, and the Toxic Substances Control Act. The Committee submitted comments to the Califor nia Environmental Protection Agency's (CalEPA's) Office of Environmental Health Hazard Assessment on the draft version of Addendum Health Risk Assessmerit ofAmbient Fugitive Vinyl Chloride Emissions From the Class I Unit ofthe B.K. Landfill, West Covina, Cali fornia. CalEPA recalculated the carcinogenic potency of vinyl chloride based on PBPK modeling data sub mitted by the Committee and found the risk to be 137 times less than the original value used in the Adden dum. The Committee is working with the University ofLou isville to conduct a case-control study of brain cancer and vinyl chloride exposure in 3,300 workers from chemical plants in the Louisville, Kentucky area. Re peated epidemiological studies have confirmed the as sociation between development of angiosarcoma of the liver and vinyl chloride exposure, but have not confirmed an association with brain cancer. A peer review process was used to ensure the quality of the study design. The Committee's outside consultant delivered an in terim report on the vinyl chloride cohort study update. The consultant has completed the framework for a re lational database of 10,173 workers exposed to vinyl chloride since 1942. The database will link all files on the cohort and allow instant updating of the vital status of cohort subjects. The database also will be used as a , central electronic archive for the study. PLANS: The Committee will comment on ATSDR's proposed methodology for developing a Minimal Risk Level (MRL) for vinyl chloride. ATSDR defines an MRL as an estimate of the daily human exposure to a hazardous substance that is likely to be without appre ciable risk of adverse noncancer health effects over a specified exposure duration. MRLs are developed un der guidance specified in the Comprehensive Environ mental Response, Compensation, and Liability Act, Section 104, and may be used to identify contaminants and potential health effects at hazardous waste sires and releases. The two-generation reproductive and developmental effects testing will begin in August. The genotoxicity study will be conducted at the same facilities as the de velopmental and reproductive studies, but it is expected to begin later in the year. This study requires the cus tom synthesis of UC2 vinyl chloride. The Committee will continue an open dialogue with EPA/NCEA to update the entry for vinvl chloride in IRIS. The University of Louisville brain cancer study is ex pected to begin in late summer. The Committee will continue to monitor progress on the vinyl chloride cohort study update. Vinyl Chloride Panel: Transportation The Panelformed in 1991 to address safety issues in the transportation of vinyl chloride monomer. In 1992, the Panelformed the Vinyl Chloride Transportation Network toprovide technicalexpertise andassistance by the industry and contractors to emergency responders at vinyl chloride CMA 114998