Document Kp4G31x2Z1Y271kQR8BjmONx

April 22,1997 William Cibulas, Ph.D. Chief, Research Implementation Branch Division of Toxicology Agency for Toxic Substances & Disease Registry 1600 Clifton Road, NE Mailstop E29 Atlanta, GA 30333 Re: Vinvl Chloride MOU Dear Dr. Cibulas: Enclosed are interim progress reports on the two-generation reproductive and developmental toxicity studies of vinyl chloride in CD rats that the CMA Vinyl Chloride Health Committee Panel is sponsoring pursuant to our Memorandum of Understanding (MOU) with the Agency for Toxic Substances and Disease Registry (ATSDR). As you have discussed with our counsel, Caffey Norman, also enclosed is a revised study plan indicating that these reports will be submitted together in April 1997. The modified study plan also reflects that I am replacing Dr. Robert Venezia as Project Manager. We will assume that the modified study plan is acceptable unless we hear otherwise from you. On October 25,1996, we informed you that the combined reproductive and developmental study would be initiated within a few days. You will see from the progress reports that dosing of the animals did not actually begin until January 7,1997 for the reproductive study and March 19,1997 for the developmental study. The delay was attributed to the resolution of a number of technical issues including additional time for setting up the chamber generation system and monitoring for leaks. Good Laboratory Practices characterization of the test material, calibration of gas chromatographs for periodic monitoring of the exposure concentrations and for comparison with infrared spectrophotometer results, and extension of the mating period for six days to achieve additional matings. Please call me at 703/741-5639 if you have any questions or need additional information. Sincerely, Enclosures (3) cc: W. Caffey Norman, Esq. Wendy K. Sherman Manager, Vinyl Chloride Panel CMA 114991