Document 999LxjNQqLgLze0MM2O3odYaR

******* draft ******* Mr. W. P. Ellis Director of Research Amchem Products, Inc. Foster Division . _ P. 0. Box 9695 Philadelphia, PA 19131 Dear Mr. Ellis: This is in response to your letter of June 30 and confirms our telephone conversation of July 16, 1975. As we discussed, asbestos has received a great deal of adverse publicity in the 7ast few years and has been the subject of a number of government regulations. A balanced picture of the current situation published by the Asbestos Information Association is attach ed for your general information. One important reason for much of the asbestos-health controversy is the long time periods, typically 20-50 years, for asbestos related diseases to develop. This, combined with the fact that low levels of asbestos fibers occur naturally in the environment, makes it difficult to define accurately a dose-response curve and say with absolute certainty what exposure levels are safe. About four years ago, the National Institute of Occupational Safety and Health reviewed the available asbestos data in great detail and recomnended a maximum occupational time-weighed average exposure level of 2 fibers/cc. longer than 5u. This recommendation was incorporated into the OSHA regulations and, after a delay to allow asbestos users to achieve compliance, goes into effect on July 1, 1976. DRAFT cont. -2 At about the same time, the National Academy of Sciences reviewed the problem more broadly in terms of potential environmental hazard and concluded that the general public is at prese.; in no danger from the small amounts of asbestos fibers now in the air and water. Due to the uncertainties in the dose-response curve, however, they did recommend that regulations be promulgated to keep the levels from increasing. Your particular inquiry was directed to possible hazards to the user from small quantities of "Calidria" asbestos incorporated as a thickener in adhesives and coatings. For this end use, the asbestos would be wetted with a substantial excess of long-lasting binder. Under these circumstances, it- * is reasonable to expect that any fiber release would be so slow that fiber concentration changes would be indistinguishable from the natural background. There are two possible exceptions to this that should be noted, spraying and sanding. If your products are applied by spraying, it is possible to generate fiber levels above background but still within the 2 fibers limit during the actual spraying operation. The same is true when asbestos contain- ed in a resin binder is sanded or abraded. t We h there are any lation that you need. If i. ry truly yours, B. Rhodes hnology Manager HBRrpcr typed 7/18/75 A 'i 0 ^ C 7