Document mpXzNoOOGYaggVpn9oeGvKVyQ

FILE NAME Brakes BRK DATE 1971 DOC BRK035 DOCUMENT DESCRIPTION Book Excerpt - Asbestos - Committee on Biologic Effects of Atmospheric Pollutants THE NEED FOR AND FEASIBILITY OF AIR POLLUTION CONTROLS Committee on Biologic Effects of i ! Atmospheric Atmospheric Atmospheric Pollutants i DIVISION OF MEDICAL SCIENCES i i NATIONAL RESEARCH COUNCIL NATIONAL ACADEMY OF SCIENCES WASHINGTON D.C. 1971 Date 22 ASBESTOS | into the surrounding environment unless effective air cleaning is applied to effluents Fibers removed by ventilation and filtering devices and not reintroduced into the production process and asbestos- ultimately containing waste products of the manufacturing process are disposed of outside the plant | | ! USE OF PRODUCTS CONTAINING ASBESTOS Many products at times unknown to the user contain asbestos of one kind or another There are great variations among such products with respect to the chances of fiber release during the use of the pro- with duct The likelihood depends predominantly on the case which the fibers can be dislodged by the application of energy and the de- degree to which the application of energy actually destroys the fibers during the use of the product Almost all the asbestos fiber usedin the United States for manufacturing products becomes tightly bound within the products and usually undergoes little actual abrasion or - wear before being discarded Asbestos cement products accounting for most ofthe asbestos usedin the United States shingles and floor tiles are in this category Some containing products such as brakelinings | are subjected to great friction their rate of is con- wear i siderable and at times they are almost completely worn away In the - case of brakelinings the application of energy is so intense and the heat created so great that most chrysotile fibers are destroyed by be ing converted to another substance whichis nonfibrous Nevertheless an appreciable percentage ( - % remains as fibrous asbestos In some products example asbestos cloth paper and sprayed fireproofing materials fibers are not tightly bound or mixed with another material that holds them in place Fiber release from these products occurs primarily during application and removal The spray fireproofing of buildings with asbestoscontaining materi- sion of als is a case in point This operation can be a serious source in that it usually in densely populated areas emis- | Talc is mined and milled and usedin greater quantities thanis as- bestos inin the United States Because it contains asbestos fibers its uses will add to the total number of fibers including nonasbestos fibers emitted The use of talc in dispensing pesticides over wide areas of the country and its use in cosmetics are two examples of how this material may act as a source of asbestos and other fibers Sourc ; DEMO For y some 1 than ' of ast are op family insulat have b be an SOLIP Solid v produ source gard to posal o municip source