Document aqaVB92JLLdVbOmXqBDJN8LB

JUL 0 6 1987 DISTRIBUTION inti OWENS-CORNING FIBERGLAS CORPORATION LARRY T SOLARI Vic< kd General Manager Insulation Operating Division June 29, 1987 R. L. King Distribution Inti. P.O. Box 15660 Houston, TX 77220 [July 6. 1987 DISTRIBUTION INTERNATIONAL P.O. Box 15660 8000 Market Street Houston, Texas 77220-5660 1 Dear R. L. King: We clearly understand that the safe use of fibrous glass products is fundamental to your business. The purpose of this letter is to advise you on the most recent evaluations of health data concerning fibrous glass and to put in context what you may hear or read. Owens-Corning has always had a strong commitment to product safety. In fact, we have initiated and supported extensive research into the health effects of glass fibers since the company was founded in 1938. To date, over 400 studies have been performed, many by the world's leading scientists. This body of research has not established a cause-and-effeet relationship between glass fibers and the develop ment of disease in man. And that continues to be the case. None theless, the subject remains a complex one, open to continuing scientific debate. For a number of years, scientists around the world have convened periodically to review the status of glass fiber research. The de velopments at recent conferences have been important and newsworthy. Most recently, the International Agency for Research on Cancer (IARC), a group of scientists affiliated with the World Health Organization (WHO), completed a conference on man-made mineral fibers in Lyon, France. At this conference, glass wool was classified as a possible human carcinogen based substantially on studies in which animals were ex posed to glass fibers through injection or implantation, proce dures that bypass normal body defense mechanisms. Comprehensive animal inhalation studies (the more normal means of exposure) have not established an association between glass wool and cancer. In fact, a recent seven-year study conducted at the Los Alamos National Laboratory showed no evidence of cancer or other res piratory disease in animals from breathing fibrous glass in concentrations greatly in excess of those found in the working environ ment. However, the IARC classification protocol is a complicated one. The agency's rules are such that its classification was estab lished largely on the basis of the injection or implantation data. LAM 002229 DPMC-17918 Page 2 In a very positive development at the conference, IARC concluded that extensive human studies did not establish a link between ex posure to glass fibers and cancers. The most recent findings of an epidemiological study by the University of Pittsburgh, which is tracking a group of U.S. factory workers, some of whom were first employed in the industry more than thirty years ago, were reported at the conference. This study found that there were no statisti cally significant differences in lung cancer rates between workers and the population in their local communities. This finding updates preliminary data, reported at a WHO confer ence last fall, which had suggested a higher lung cancer rate for those workers. This report received considerable press attention in the Wall Street Journal, New York Times and other national and local publications. However, at that time, the workers had been compared to the national population -- a less meaningful comparison -- be cause differences in local cancer rates had not yet been analyzed. Importantly, at no time did the University of Pittsburgh data show the "dose-response" relationship scientists look for in drawing conclusions about the cause of disease; that is, there was no re lationship between the length of employment or the intensity of exposure and the lung cancer rate. Determining the health effects of fibrous glass is a complex process and one which merits our continuing attention and investigation. We are encouraged by the IARC report on the data from human studies. Even though we respect IARC's evaluations of the animal studies, we do know that there is substantial debate within the medical com munity as to the relevance of their conclusion. The latter point notwithstanding, we will revise our product information to reflect IARC's conclusion. We find the conclusions reached at the IARC conference about glass fibers, on the whole, reassuring. Nevertheless, in recognition of the open issues addressed at the conference, we will continue to support comprehensive research programs, accelerating this process as we can. We will keep you informed as to any new or important developments, and hope you will contact us with any questions you may have. You can be assured of our continued commitment to product safety. Sincerely, LAM 002230 DPMC-17919