Document JvKbmM7L9BDo4rm9pObwkNn7a

ETHYL CORPORATION # To Mr. Bill Baker INTER-OFFICE Address Tiptonville FnoM J. G. Burdick G. L. Ter Haar BRT 3 Address BRT 4 Subject Vinyl Chloride Exposure Date May 13, 1977 You indicated that some of your employees were concerned about their exposure to vinyl chloride. They were concerned not only about their current exposure but also about exposures that might have occurred before residual monomer in the compound was reduced to today's low levels. There have been cases reported of deaths due to liver cancer of workers employed in the manufacture of polyvinylchloride. However the best estimate of their exposure was two or more orders of magnitude higher than vinyl chloride levels in the Tiptonville plant or any other plant engaged in working with the PVC compound. Mr. Bob Cope conducted an extensive survey of the Tiptonville plant in 1974. All average exposures were below the very strin gent standard of 1 ppm. Of 99 samples taken, only six were over 1 ppm and the highest value was only 4 ppm. Thus with these very low exposures, you and your employees can be assured that ex posures have always been low and far below those levels which are believed to have caused the liver cancer. In 1976 we again conducted a survey for vinyl chloride at Tiptonville. All values were less than 0.1 ppm. This reflects the progress that has been made to significantly lower the re sidual vinylchloride in the final compound. These show that worker exposure at the Tiptonville plant has always been minimal and today is even lower, seldom above 0.1 ppm. Your employees asked if tests are available which would tell if they had any problem resulting from working with PVC compound. The only test which is capable of identifying evidence of liver damage, typical of vinyl chloride exposure, is liver biopsy. This is a surgical procedure which should not be done without a clear indication. The enzyme tests called for in the OSHA stan dard are very nonspecific and may be abnormal for a variety of reasons including abnormalities of heart, kidneys, bones, etc. There are no specific tests indicated for the employees at Tiptonville. Medical Director GTH/JGB:ws Director, Toxicology and Industrial Hygiene Department