Document XzjY7goMNXkGYE1JL0r485Z2G

Bell Laboratories 600 Mountain Avenue Murray Hill, New Jersey 07974 Phone (201)582-3000 May 8, 1979 P. A. Muller New York Telephone Company 140 West Street Room 2250 New York, New York 10007 Dear Pat: The two air filters and bulk insulation samples you sent have been analyzed for asbestos. Insulation Sample The bulk insulation sample labelled 45 FI. Exxon Building 9 was analyzed by polarized light microscopy which found many non-birefringent fibers (probably mineral wool) and some asbestos-like birefringent fibers. An x-ray diffraction scan revealed the major crystalline materials present were chrysotile ( a form of asbestos) and calcite. The presence of chrysotile and the birefringent fibers means this material contains asbestos. Air Filters The two air 'filters were analyzed by counting all fibers greater than 5 um long seen by phase contrast optical microscopy at 400x. This is the method recommended by the National Institute of Occupational Safety Health (NIOSH). Based on your sampling data and the microscopy counts the results were: i 003773 Ms. P. A. Muller - 2 Sample #1 Exxon Building 45 Floor Tel Room Blank Volume Air (L) 120 --- Fibers Counted* 13 5 Uncorrected Fibers/cm3 .08 ... Blank Corrected Fibers/cm3 .05 -- -- &2 100 microscope fields .011 mm /field) were counted. The filter area was 855 mm^. If you have any further questions about this analysis please let me know. Sincerely, Gj&cQw&h Charles P. Lichtenwalner Ref: 1023 Copy to P. H. Stark - NYT C. H. Steinmetz, M.D. R. L. Beach - ATT N. J. DeCapua J. M. Degen R. W. Stone, M.D. W. J. Schreibeis - BTL G. M. Wilkening CONFIDENTIAL 003774