Document V32D3wqzdRxObMyx5qz54LYoj

r: 1-* 40J CG-3 Bel] Laboratories 600 Mountain A <enue Murray Hill. New Jersey 07974 Phone 1201) 5-J2-3000 January 22, 1981 Mr. R.R. Rishavy Southwestern Bell Room 1500 200 South Fifth Street Minneapolis, MN 55402 Dear Mr. Rishavy: The four insulation samples you sent have been analyzed for asbestos by Walter C. McCrone Associates - a microscopy laboratory. They used polarized light microscopy with dispersion staining for analysis. The results are given below. 1. Pipe Insulation, 8th Floor, A Building, Market Street, St. Paul, Minnesota. Two forms of asbestos were noted in this sample, approximately 10-15% chrysotile and 10-15% amosite. The majority of the sample was limestone. 2. Pipe Insulation, Compactor Room, A Building, Market Street, St. Paul, Minnesota. The sample contained 15-20% chrysotile asbestos. The majority of the sample was limestone. 3. Pipe Insulation, Heating Tunnels, St. Cat herines, St. Paul, Minnesota. Two forms of asbestos rere noted in this sample, approximately 5-10% chrysotile nd 5-7% amosite. The majority of the sample was limestone. 4. Siding Material, CDO, Royalton, Minnesot. This sample was found to be asbestos reinforced cement, It contained approximately 3-5% chrysotile asbestos. The three air filter samples from the heatim tunnels at St. Catherines (AJS-1) and at St. Thomas (Ajj|-2) were analyzed by myself by counting all fibers greater than Sum long seen by phase contrast microscopy at 40( ;<. This is the method recommended by the National Institute of Occupational Safety and Health (NIOSK) for airborne asbestos analysis, Note, however, that it is not specific for asbestos since all fibers meeting the size criteria are counted. Based on your sampling data and the optical counts -the results were: CONFIDENTIAL 003855