Document 7O5LQLn4yEmDNx67Vz9MMwqDE

CHEMICAL MANUFACTURERS ASSOCIATION March 20, 1987 Dr. Nancy B. Pate U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Mail Drop 12 Research Triangle Park, NC 27711 MAR 3 0 1987 I'M_____ ^ I Re: Proposed Test Rule for 1,1-Dichloroethylene 51 Fed. Reg. 28840 (August 12, 1986) Dear Dr. Pate: I would like to thank you for your help in making the February 12, 1987 hearing the successful technical dialogue that we had hoped it would become. Your participation in the meeting and your more recent explanation of the use to which an oncogenicity test would be put by the Air Office help us understand the role of this test rule in the possible future activities of the Air Office and the EPA State Initiative Program. I was particularly interested to learn that a test rule for VDC is seen as potentially helpful to EPA, not in improving risk assessment, but rather in enrolling VDC in the State Initiative Program. As you know from our hearing statements, the Panel believes that the proposed test rule is inappropriate because the present data base for VDC is sufficient to enable the Agency reasonably to predict carcinogenic effects without the need for another oncogenicity study. We do feel that it is inappropriate to seek oncogenicity data through the test rule mechanism when the Agency can already assess risk. The ability of states to act under the State Initiative Program should not be a motivating factor in issuing a test rule. I would like to give you additional information as a follow-up to the hearing. Of particular interest to your office is the information that I provided regarding CMA's emissions survey. As I noted at the hearing, CMA has received additional survey responses from a number of companies that had not responded by the time the Panel's written comments were filed. This new information was detailed in my oral remarks, a copy of which is enclosed. Formerly Manvfac:.. ir,g Chemists Association--Serving me Chemical industry Since 1872 2501 M Street NW Washington DC 20037 hgiecno^e 202;887-1100 Telex 8961 7 (CMA WSH) SL 063144 Dr. Northrup asked an important question regarding the significance of the survey results. He inquired whether the uses of VDC were likely to vary over time in such a way that the emissions data could change. We have discussed this issue with members of the industry, including importers of VDC based copolymers and have learned that it is unlikely that the use of VDC will expand. A review of the past few years demonstrates that the user industry is shrinking. If you compare the number of sites at which VDC was used a number of years ago as reflected in the Health Assessment Document, with the number of sites reporting current use in the CMA survey, you will see that the number of sites reporting VDC use has significantly declined. Thus, if there is any change in the industry over the next few years that is likely to affect emissions, it will be reflected in a decrease in sources of emissions. Finally, we are looking into the questions raised by Dr. Greenberg at the hearing. Certain of those questions would require additional review of the literature to determine what further data exist. These data may be useful in refining the Agency's risk assessment through pharmacokinetic modeling. We also hope to have further information and suggestions for Dr. Greenberg in the very near future. If you have any further questions, please do not hesitate to contact me at (202) 887-1198, Sincerely yours, Enclosure cc: C. Glasgow Robert R. Romano, Ph.D. Associate Director, Special Programs & Manager, VDC Panel SI 63U5 February 12, 1987 CMA's VDC EMISSIONS AND EXPOSURE SURVEY RESULTS by Robert R. Romano Good afternoon. On behalf of CMA's VDC Panel I am pleased to be here. In an effort to generate data which would provide a more reliable basis upon which to estimate exposure, CMA conducted a survey of manufacturers and processors of VDC. A confidential questionnaire was sent to each company identified in the HAD, as well as to customers of the manufacturers. The survey was seeking information regarding emissions from process vents, storage tanks, and fugitives. Estimates of populations residing within five miles of plants and distances from VDC process facilities to property boundaries and to the nearest residents were also obtained. Finally, the questionnaires asked about the availability of meteorologic data and of occupational monitoring data. 1. Number of VDC Manufacturers and Processors The survey revealed that many of the companies listed in the 1985 HAD no longer use VDC. Of a total of 42 companies reported by EPA to be producing or using VDC 31 companies responded to the survey. Of these, 15 companies indicated that they no longer used or produced VDC leaving only 16 companies using or producing VDC. All major processors did submit responses, and the manufacturers of VDC believe that the 11 companies that did not respond do not presently use the chemical. 2. Quantity of VDC Released The HAD estimated that emissions of VDC from these facilities amounted to 1,300,400 pounds per year, HAD at 5-12. If the CMA survey data are combined, less than 162,500 pounds per year were reported emitted through process vents, fugitive emissions, storage tanks and loading/unloading areas. While it is possible that this figure would be larger if the survey had received a 100% response rate, as opposed to 74% received to date, actual emissions are probably quite close to this figure. Because all of the major processors of VDC have responded, additional emissions are likely to be slight. In any event, the total emissions are about 8 times lower than than the 1,300,400 pounds per year estimated in the Agency's HAD. 3 Population EPA had estimated that a total of 3,573,395 people lived within five miles of producing or processing plants, HAD at 7-7. The CMA survey revealed a total of only 1,515,383 living within five miles of facilities responding. This figure is less than half that estimated by EPA. 4. Air Transport The HAD noted that dispersion modeling could theoretically provide an estimate of VDC concentrations at certain distances from the plant sites, but that such data were not presently available. The CMA SL 063146 2- - survey attempted to generate realistic data that could be used in such modeling. The distance from the source of release to the property boundary reported in the survey ranged from 100 feet to 5,900 feet with an average of about 1,000 feet. The distance from the source of release to the nearest resident ranged from 260 feet to 6,000 feet with an average of over 2,421 feet or about one half mile. The survey also revealed that meteorologic data and occupational monitoring data are available for nearly all sites surveyed. Based on the previously available emission estimates, the Agency concluded in their Federal Register notice of 1985 not to regulate VDC as a Hazardous Air Pollutant because public exposure to VDC levels were low (50 Fed. Reg, at 32634). These survey results support that conclusion, suggesting emissions nearly an order of magnitude lower than that estimated by EPA. These survey results certainly will improve the Agency's exposure assessment, and conclude that public exposures to VDC are lower than those estimated by EPA. In addition, this lower exposure will more than likely reduce the presently existing small risk of VDC to the public even more. Thank you for your attention, I will be pleased to answer any questions. SL 063147 VINYLIDINE CHLORIDE (1,1-Dichloroethylene) Estimated Emission (lbs/yr) Estimated Population EPA's HAD 1,300,400 3,573,395 CMA's '86 SURVEY 162,500 1,515,383 2/12/87 Si 063148