FIBROUS GLASS AND CANCER

Some argue that fibrous glass (glass wool) should not be considered as a likely human carcinogen and hence should not be listed in the Seven th Annual Report on Carcinogens (ARC) prepared by the National Toxicol ogy Program (NTP) and mandated by the U.S. Congress. In examining this issue, data from both laboratory experiments (animal studies) and epi demiologic studies (human data) are reviewed with the results evaluate d according to the criteria established by the International Agency fo r Research on Cancer (IARC) and adopted in slightly modified form by t he NTP for classifying substances as human carcinogens or likely human carcinogens. From our comprehensive review of the available informati on, we conclude that fibrous glass materials are carcinogenic, and in view of the NTP and IARC definitions should be listed in the ARC. Our review then examines the carcinogenic potency of glass fibers to human s in comparison with asbestos fibers and concludes that on a fiber-per -fiber basis, glass fibers may be as potent or even more potent than a sbestos. The implications of these findings are then presented for reg ulatory purposes in the occupational setting. (C) 1994 Wiley-Liss, Inc .