Document KRONk4BbZGQoVwxOyL6dnQYb6

R&S 113709 *1 CHEMICAL MANUFACTURERS ASSOCIATION May 29, 1980 Mr. Frank D. Rover Chief Chemical Hazards Identification Branch Assessment Division Environmental Protection Agency 401 M Street, S. W. 611 East Tower Washington, D. C. 20460 Dear Mr. Rover: Reference is made to our letter of March 19/ 1980 in which we mentioned that the Chemical Manufacturers Association (CMA) planned to conduct a histopathological examination of all remaining brain tissues in the flawed vinyl chloride inhalation study conducted at Industrial Bio- ( Test Laboratories (IBT). This investigation has now been completed by Dr'.William Busey of Experimental Pathology Laboratories/ Inc. and his pathology report is enclosed. Dr. Busey's findings revealed the existence of seven olfactory neuroblastomas in rats exposed to vinyl chloride in the highest dose group. These tumors are of the same type as those reported by Maltoni in animals exposed to a similar concentration/ and are thus supportive of his findings. In addition/ CMA also contracted with Dr. Bob West of Bob West Associates to conduct a review and audit of chamber concentration monitoring, body weight data, animal acquisition, and mortality logs. His report is also enclosed. Dr. West found numerous inconsistencies in the conduct of the study and concluded that results could be interpreted in a qualitative manner only. After reviewing the reports, CMA considers that the IBT data do not warrant further study and CMA will be Formerly Manufacturing Chemists Association--Serving the Chemical Industry Since 1872. 1825 Connecticut Avenue, NW Washington. DC 20008 T iephone 202/328-4200 Telex 89617 (CMA WSH) negotiating for a settlement with IBT shortly. Sincerely, HCS:md Enclosures Hasmukh C. Shah Director Special Projects R&S 113710