| Agent Name |
Asbestos |
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| CAS Number |
1332-21-4, 12001-28-4, 12172-73-5, 77536-66-4, 77536-67-5, 77536-68-6, 132207-32-0 |
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| Formula |
varies |
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| Major Category |
Mineral Dusts |
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| Synonyms |
Chrysotile; Amosite; Crocidolite; Anthophylite; Tremolite; Actinolite; |
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| Category |
Fibrogenic Dusts |
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| Description |
White or greenish (chrysotile), blue (crocidolite), or gray-green (amosite) fibrous, odorless solids; [NIOSH] |
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| Sources/Uses |
Used to make cement pipe, vinyl floor tile, flooring felt, shingles, roofing felt, sealants and plasters, acoustic tile, paper products for insulation and filtering, brake linings and clutch facings, curtains, and spray-on products for fireproofing and insulation; [ATSDR Case Studies, Asbestos Toxicity] Serpentine group: chrysotile (95% of world's production); Amphibole group: amosite, crocidolite, actinolite, anthophylite, and tremolite. Tremolite and actinolite were not used commercially, but may contaminate ores of talc, vermiculite, and chrysotile. Anthophylite was mined only in Finland and not after 1970. [Rom, p. 298; Harber, p. 296; Rosenstock, p. 413-5] |
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| Comments |
In the past, the highest exposures occurred in insulators, shipyard workers, and other workers manufacturing asbestos products. Today, construction workers are the most heavily exposed from maintenance, renovation, and demolition of buildings insulated with asbestos years ago. [ATSDR Case Studies, Asbestos Toxicity] As a general rule, exposure to asbestos for less than 6 months is unlikely to cause interstitial fibrosis or pleural thickening. Among workers heavily exposed to asbestos with interstitial fibrosis, about 1/2 also have pleural thickening. Among those with pleural thickening, less than 30% have interstitial fibrosis. [Rosenstock, p. 367-9] Although the epidemiological evidence shows that asbestos exposure is associated mainly with restrictive lung function impairment, obstructive changes are also seen. [Asthma in the Workplace, p. 690] An obstructive pattern (reduced FEV1/FVC) is not likely to be seen in nonsmoking workers with asbestosis, and there is no evidence that asbestos causes emphysema. [Hendrick, p. 148] |
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| Restricted |
Since 1975 the use of asbestos in insulation materials has been banned in the U.S.A. |
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| Reference Link |
OSHA Technical Links: Asbestos |
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| Exposure Assessment |
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| Skin Designation (ACGIH) |
No |
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| Bioaccumulates |
Yes |
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| TLV (ACGIH) | 0.1 respirable fiber/cc |
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| PEL (OSHA) | 0.1 fiber/cc, STEL(OSHA) = 1 fiber/cc(30 min) |
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| Half Life |
very long; |
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| Reference Link |
ATSDR - ToxFAQs - Asbestos |
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| Adverse Effects |
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| Fibrogenic |
Yes |
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| Lung Cancer |
Yes |
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| IARC Carcinogen |
Known Carcinogen |
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| Links to Other NLM Databases |
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| Health Studies |
Human Health Effects from Hazardous Substances Data Bank: ASBESTOS
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