| Agent Name |
DIISOCYANATES |
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| Alternative Name |
CLASS |
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| Major Category |
Plastics & Rubber |
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| Category |
Diisocyanates |
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| Sources/Uses |
MDI is used to make rigid foams, while both TDI and MDI are used to make flexible foams, elastomers, and surface coatings. The diisocyanate chemicals, e.g., TDI or MDI, along with various polyols, catalysts, blowing agents, surfactants, and other agents are needed to manufacture urethane polymers. [Klees JE, Ott MG. Diisocyanates in Polyurethane Plastics Applications. Occup Med STAR 14(4):760-2,1999] |
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| Comments |
Diisocyanates, also referred to as isocyanates, are organic compounds with two isocyanate groups (-NCO). They are used to make polyurethane coatings and rigid and flexible foams. Isocyanates are the leading cause of occupational asthma in many post-industrial countries where incidence rates have been measured. Commonly used isocyanates are toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI) and polymethylene polyphenyl isocyanate (PAPI). [LaDou, p. 320; LaDou (2nd ed.), p. 521-3] Exposure can occur to vapors at room temperature (TDI and HDI), or after heating (MDI and PAPI), or during spraying processes (all isocyanates). [Sullivan, p. 470-2] "Isocyanate HP," a form of hypersensitivity pneumonitis, has been reported. [Rosenstock, p. 346] Some are known skin sensitizers. See "MONOISOCYANATES." |
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| Reference Link |
OSHA Technical Links: Isocyanates |
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| Exposure Assessment |
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| Skin Designation (ACGIH) |
Not evaluated |
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| Adverse Effects |
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| Asthma |
Yes |
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| Fibrogenic |
Yes |
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| Skin Sensitizer |
Yes |
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| Links to Other NLM Databases |
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