Document 4JjgaXEm1bboGMroerayYxnqe

' GARY TER HAAR I fctWCTO" !YL CORPORATION >CDkOOY AMD tMDWVrfclAL tfWtMt PkDftiD* DcvD. Baton Rowad* Ia. 70BOI BYL CORPORATION C0iOT AMD IN9UITii4i HVAttMI DCPAjrTMtMT iThyl Tower, 451 Florida X>n ROuoe, Louisiana. 70801 ovember 2, 1977 The Honorable Eula Bingham Assistant Secretary for Occupational Safety and Health Department of Labor 200 Constitution Avenue, N.W. Washington, D.C. 20210 * The Honorable Douglas M. Costle Administrator Environmental Protection Agency 401 M Street, S.W. Washington, D.C. 20460 Dr. John F. Finklea , National Institute for "'Occupational Safety and Health 5600 Fishers Lane Rockville, Maryland 20852 Dear Dr. Bingham, Costie and Finklea: Ethyl Corporation wishes to advise you of recent findings regarding the toxicology of vinyl bromide. The acute toxicity of this compound has been known for many years. The current TLV recommended by ACGIH is 250 ppm. However less has been known about the chronic toxicity of vinyl bromide. To resolve these uncertainties Dow, Dow-Badiscne, Ethyl and Monsanto are currently sponsoring an inhalation study of vinyl bromide in rats. This study, underway at Huntingdon Research Center is planned to continue for approximately two years, the lifetime of the animals. Exposures are at 1250, 250, 50 and 10 ppm of vinyl bromide in air. The results from the first year of study have just become available as part of the first year report from Huntingdon Research Center. These preliminary results indicate a statistical increase in the incidence of cancer at the 1250 and 250 ppm levels. Cancer of the liver, similar to that seen with vinyl chloride, was evident in 9 of 48 animals at 1250 ppm and 2 of 30 'animals at 250 ppm. There was also som in crease in other tumors at these two high levels of exposure. No liver tumors were seen at 50 or 10 ppm nor was there a statistical increase in any tumors compared to control .animals at these two lower exposures. This study will continue for another year. The report of the results of the first year of the study will be sent to in terested government agencies upon request. As we were uncertain whether there might be similarities between vinyl bromide and vinyl chloride, we have had as our guide line a limit of exposures in the workplace for vinyl bromide of VC1221 1 ppm, the same as that for vinyl chloride. We have sampled many times for vinyl bromide in the work place in Magnolia, and the'average is well below 1 ppm. in addition, representatives of NIOSH recently completed a survey in our plant with similar results. The results of the Ethyl surveys and the NIOSH visit are also available upon request. We believe that the results on animals at these levels of exposure, much higher than our workplace levels, do not suggest a risk to health exists in our workplace. We will continue to strive for minimum exposure to vinyl bromide in the workplace. The excellent cooperation among all employees in our plant should insure that safe working conditions will continue. GTHrws I Director VC1222