Document gaajmkZE34m1bX0M7p7GqVGzG

CM CHEMICAL MANUFACTURERS ASSOCIATION '! \ June 30, 1987 ja \ ^ Gerald A. Emison Director Office of Air Quality Planning & Standards United States Environmental Protection Agency Research Triangle Park, NC 27711 Re: Testing of Vinylidene Chloride Under Section 4(a) (1WA) of TSCA Dear Mr. Emison: I am writing on behalf of the Chemical Manufacturers Association Vinylidene Chloride ("VDC") Program Panel to convey our concerns about the proposed use of Section 4 of the Toxic Substances Control Act to require yet another long-term study of VDC. I would also like to request a meeting to discuss these issues. As you know, EPA is authorized to require testing of chemical substances under section 4(a)(1)(A) of TSCA only on making the following findings: first, that the manufacture, use, distribution or disposal may present an unreasonable risk; second, that the available data are insufficient to enable EPA to reasonably predict or determine the health effects; and third, that the proposed testing is necessary to enable the Agency to make such a prediction. The VDC panel believes that the present extensive data base is sufficient to enable EPA to make a reasonable prediction of possible carcinogenic effects without the need for another oncogenicity study. The Agency's ability to make a reasonable determination or prediction of carcinogenic effects of VDC is well established. The air office -- using existing data -- evaluated potential human risk in its consideration of VDC under Section 112 of the Clean Air Act. The agency prepared a Health Assessment Document, which contained a carcinogenicity risk assessment, and concluded that possible risks are extremely small. While the Panel may not agree with all of the details of the EPA risk assessment, it is clear that the Agency can make a reasonable prediction of risks. We understand your desire to obtain a better data set on which to base an estimate of cancer potency. It is certainly possible to improve the data base for assessing VDC Formerly Manufacturing Chemists Association^Semng the Chemical industry Since 1872 2501 M Street NW Washington DC 20037 Telephone 202. 887-1100 Telex 89617 (CMA WSH> Si 063040 Gerald A. Emison June 30, 1987 Page 2 carcinogenicity, as it is with any chemical, regardless of how extensive the current data base is. However, a test rule under Section 4(a)(1)(A) of TSCA is not available to the Agency simply to improve the data base, when a reasonable prediction of carcinogenic potential can be made on the basis of the already extensive data. The CMA VDC Panel has expressed its willingness to work with the Office of Air Quality Planning and Standards to improve the Agency's risk assessment for VDC in a way that does not require that the Agency exceed its authority under Section 4 of TSCA. The Panel has conducted a survey of manufacturers and users of VDC to better estimate emissions and potential exposures to VDC. This information, together with information on pharmacokinetic modeling, may assist the Air Office in improving its risk assessment for this chemical. We would welcome an opportunity to meet with you and your staff at your offices to discuss these issues. We would suggest July 23 or 30 as possible meeting dates. If you have any questions, please do not hesitate to contact us. We are awaiting your response regarding the meeting. cc: Ron Campbell John O'Connor Gary Timm Robert R. Romano, Ph.D. Manager, Vinylidene Chloride Panel Program Panel 063041