Document QYDa6MX86dQEYdK5groNzZdL
Case: 48106-3 Reference: 1744 4 1746
Bell Laboratories
600 Mountain Avenue Murray Hill. New Jersey 07974 Phone (201) 582-3000
August 30, 1933
Ms. Vicki Orchier New York Telephone Company Room 1102 1095 Avenue of the Americas New York, New York 10036
Dear Vicki:
The four air filter samples you submitted have been analyzed for asbestos fibers. As indicated on your sampling data sheets, the samples were collected at 400 Westchester Avenue on 7/20/83 and 7/21/83.
Filter samples were analyzed in accordance with NIOSK P&CAM 239. This method involves sizing and counting fibers using a phase contrast microscope. All fibers which have a physical dimension longer than 5 micrometers (ym) and a length to diameter ratio of 3 to 1 or greater, are counted.
Fiber concentrations, expressed as fibers per cubic centimeter (fibers/cc), were calculated from the sampling data you provided and the analytical data. Results are listed on the attached Table.
The Occupational Safety and Health Administration's fOSHA) 8-hour permissible exposure limit (PEL) for asbestos is 2 fibers/cc. The OSHA 8-hour action level is 0.1 fibers/cc.
Since sample concentrations are above the OSHA action level, 8-hour time weighted average, concentrations should be evaluated.
Please call if you have any questions.
Sincerely
MH-78691-PAH-mpb Copy to (see attached)
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