Document mqGDDqXjK5EVYYvb5z0nez75B

2- - ) i 1 URL 18307 of safety in present standards should results at the highest levels prove negative, and (3) demonstrate a dose response relationship over a useful range of concentrations in the event of positive findings. The three exposure levels best meeting these criteria were judged to be Highest Level -- 5,000 ppm Intermediate Level -- Lowest Level -- 500 ppm 50 ppm. 2.2 Selection of Material Source All agreed that, in the light of current data, there remained no compelling justification for duplicate test programs with acetylene and ethylene derived vinyl chloride monomer. The offer of PPG Industries to pro vide material for the exposures was accepted by the Research Coordinators. 2.3 Selection of Test Species Telephone consultation with Industrial Biotest confirmed the Research Coordinators' estimates that exposure chamber space was adequate to add a third small rodent species to each of the chambers, and that, if this were done without increasing the total animals involved (2000 animals for the four exposure groups plus control included in the basic research package, but not including the additional group of animals proposed to be paid for by separate contributions from producers of acetylene derived vinyl chloride) any change in project costs would be in the downward direction. Hamsters or gerbils were mentioned as possible candidates for the third species, with final selection to be made after consultation with Industrial Biotest. 2.4 Protocol Summary The proposed protocol would thus provide for the following exposures: Animals (Equally divided as to sex) Chamber VCM Concentration Rats Mice Hamsters(?) Total 1 control 200 200 100 500 2 50 ppm 200 200 100 500 3 500 ppm 200 200 100 500 4 5,000 ppm 200 200 100 500 800 800 400 2,000 -3- 3. Epidemiological Studies The Secretary was asked to solicit proposals for an industry wide epidemiological survey to determine whether or not there was an increased incidence of malingnancy among workers exposed industrially to vapors of vinyl chloride monomer. The following organizations were mentioned as competent to design and perform such a study: The Epply Institute Stanford Research Institute Harvard University's School of Public Health University of Michigan's School of Public Health Kettering Institute Tabershaw Cooper. After proposals have been received from a suitable number of offerers, the Research Coordinators will for mulate a recommendation to the Technical Task Group on Vinyl Chloride Research on action to be taken. 4. Metabolic Studies Discussions on the justifications for and design of comparative studies on the metabolism and detoxication of vinyl chloride monomer in experimental animals and man were postponed until early results from the chronic exposure studies are available for review. 5. Literary Survey Dr. Torkelson expressed his opinion that the available literature on the toxicology and metabolism of vinyl chloride monomer was relatively limited, but offered to have the Dow library prepare a compilation. The bibliography when compiled, will be distributed to both the Research Coordinators and the Technical Task Group. 6. Schedule The Research Coordinators expressed their hope that the animal exposure program could be started as soon URL 18308 as possible in 1973. -4- Respectfully submitted, ICi $. sJek*i j Kenneth D. Johnson Secretary Vinyl Chloride Research Coordinators J > URL 18309 Minutes Subject to Approval December 6, 1972 KDJsmkb