Document 6wamMmayXbkBGNeN2Ejnek8Dd

Answer to Barry Commoner accusation that Monsanto had known since the 1930's that PCBs could be harmful to workers: Although Polychlorinated Biphenols (PCBs) were tested repeatedly by Monsanto for nearly half a century, the material was never convicted of causing skin disease. In fact, each case of skin irritation attributed to PCBs was traced to (correctable) impurities in the manufacturing process. In 1933, when a skin disease began appearing among Swann chemical company workers in the PCB pilot production facility at Anniston, Alabama, the company immediately launched a medical investigation. It was determined from the study that the skin eruptions were related to impurities in the intermediate steps of the manufacturing process and not to the final product (PCBs). As a result of this investigation, steps were taken to clean up the impurities, and the manufacturing process was changed to a closed system, which permanently alleviated the problem. Patch tests conducted with PCBs (then and later) never produced any evidence of irritation. The outcome of this study was made public by two Atlanta, Ga., dermatologists who had served as consultants during the investigation ("The Archives of Dermatology and Syphilogy," Vol. 33, p. 1027, 1936). Monsanto Company, which later purchased Swann, did not experience any cases of skin disease among PCB workers during more than 40 years of PCB manufacture. However, over the years Monsanto sponsored a number of animal studies with PCBs and used the results of these tests to set exposure levels inside the plants. The PCB issue came up again in the late 1940's and early 1950's when outbreaks of skin disease occurred on board ships that used PCBs in insulating capacities. Studies of these incidents again traced the problem to other materials, such as polychlorinated naphthalenes, that were used in conjunction with PCBs. -oOo- 0676182 PCB-ARCH0745354