A Brief History Of The Membrane-Filter Method.
Asbestos Identification and Measurement. Proceedings of a Topical Symposium Sponsored by the American Conference of Governmental Industrial Hygienists 1979:3-5
The development of the membrane filter method for determining airborne concentrations of asbestos (1332214) is discussed. Prior to the formation of OSHA and NIOSH in 1970, airborne concentrations of asbestos were measured by impinger sampling and particle counting. Prior to 1976, asbestos standards were established to protect workers from asbestosis. Asbestos, however, was receiving interest as a carcinogen and NIOSH recommended a time weighted average standard of 0.1 fiber per cubic centimeter for fibers longer than 5 microns. At any time when asbestos concentrations were expressed in units of fibers per cubic centimeter, the method of measurement was counting fibers deposited on filters using phase contrast microscopy at a magnification of approximately 400. The Asbestosis Research Council of Great Britain was primarily responsible for promoting the membrane filter method. The other sampling systems and analytical techniques were eventually discarded in favor of the membrane filter method. The author notes that while the membrane filter method is a good standard method, a new method should be developed if it can identify the disease causing mechanism and the specific asbestos fiber that is the etiologic agent.
Asbestos-fibers; Airborne-fibers; Hygiene; Particle-counters; Air-monitoring; Dust-exposure; Analytical-models; Workers; Asbestos-dusts; Gravimetric-analysis;
Asbestos Identification and Measurement. Proceedings of a Topical Symposium Sponsored by the American Conference of Governmental Industrial Hygienists