Document B8ky6Jxmb91w832XkdEgGKpg4

ETHYL CORPORATION MUCMM1 MO MMItTWM mfM WtHTHWI Ethyl Towbr, 451 Florida Baton Rouoe, Louisiana 70801 J04/3M-78M July 2, 1982 Mr. Bill Persky General Dynamics Corporation Pierre La Clede Center St. Louis, MO 63105 Dear Sir: This is in response to your request for a summary of our vinyl chloride monomer monitoring experience in vinyl chloride molding operations. Ethyl owns many,j?lastics injection molding plants throughout the U.S. Twenty one of them use PVC compounds from time to time. When the vinyl chloride standard was promulgated we began monitoring for vinyl chloride monomer (VCM) in all plants that mold PVC. We soon learned that VCM exposures were insignificant. However, as a pre cautionary practice, we have continued to monitor for VCM as a part of the general industrial hygiene surveys in these plants. After your inquiry, we reviewed all of the monitoring reports. This review showed that we have taken 186 person nel monitoring samples since 1974 in injection molding operations. All of the results except one showed exposures of less than 0,1 ppm which is the practical limit of detec tion. A single sample showed a value of 0.2 ppm. As you know, the OSHA standard is 1.0 ppm 8-hour PEL, and the action level of the standard is 0.5 ppm. Obviously, there is no need for concern about vinyl chloride monomer exposures while molding PVC. In recent years residual monomer levels in PVC compounds have been closely controlled and the risk of an unusual exposure is practically nil. If you need further information, please let iis know. Sincerely, DEJ:bto .. cc: _F. "M. oeaird Assistant Director