4,4'-Methylenebis (2-chloroaniline): an unregulated carcinogen

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Am. J. Ind. Med.; (United States)

DOI:https://doi.org/10.1002/ajim.4700120508· OSTI ID:5718813

Ward, E; Smith, A B; Halperin, W

4,4'-Methylenebis (2-chloroaniline) (MBOCA) is a confirmed animal carcinogen. It is used commercially as a curing agent for polymers containing isocyanate. There are no adequate studies documenting a carcinogenic risk for MBOCA in humans; however, studies in rats and dogs have shown that MBOCA is a carcinogen. Also, MBOCA is structurally similar to aromatic amines, which cause bladder cancer in workers with occupational exposure. Manufacture of MBOCA in the United States ceased in 1979. However, estimates of the number of workers potentially exposed range from 1,400 to 33,000 in the manufacture of MBOCA-cured products. Presently, there are no federal regulations limiting occupational exposure to MBOCA. An occupational standard for MBOCA proposed by the Occupational Safety and Health Administration was remanded by the Third Circuit Court of Appeals on procedural grounds in 1974. NIOSH recommended in 1978 that MBOCA be treated as a potential human carcinogen and that worker exposure be controlled so that it does not exceed 3 micrograms/m3 of air determined as a time-weighted average concentration for up to a 10-hour workshift (the lowest level that can be reliably measured). In this paper, we will review the literature in regard to MBOCA's carcinogenicity, describe industrial use and extent of worker exposure, and review MBOCA's status in relation to occupational regulations in the United States and abroad. 51 references.

• Research Organization: National Institute for Occupational Safety and Health, Cincinnati, OH
• OSTI ID: 5718813
• Journal Information: Am. J. Ind. Med.; (United States), Journal Name: Am. J. Ind. Med.; (United States) Vol. 12:5; ISSN AJIMD
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
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CARCINOGENESIS
CARCINOGENS
CHLORINATED AROMATIC HYDROCARBONS
DOCUMENT TYPES
HALOGENATED AROMATIC HYDROCARBONS
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NATIONAL ORGANIZATIONS
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SAFETY STANDARDS
STANDARDS
US DOL
US ORGANIZATIONS
US OSHA