Assessment of the relationship between isocyanate exposure levels and occupational asthma

Am J Ind Med. 1997 Nov;32(5):517-21. doi: 10.1002/(sici)1097-0274(199711)32:5<517::aid-ajim12>;2-5.


As part of a previous study, we identified Ontario cases of isocyanate-induced occupational asthma (OA) and the companies at which they worked. The Ontario Ministry of Labour maintained a computerized database including isocyanate air sampling determinations conducted by the Ministry. Within this database, we compared levels of isocyanate concentrations measured at 20 case companies [with compensated isocyanate asthma (OA) claims] with 203 noncase companies, based on air samples collected during the same 4-year period during which the OA claims arose. The proportion of case companies that were ever recorded as having a measured ambient isocyanate concentration of > or = 0.005 ppm was greater than that for noncase companies, for TDI users (43% vs 22%), and for MDI users (40% vs 27%). This reached conventional significance when combined across companies and isocyanate types (50% vs 25%; P < 0.05). This provides some evidence that facilities having OA claims have higher isocyanate exposures than do those without claims.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / adverse effects
  • Air Pollutants / analysis*
  • Asthma / chemically induced*
  • Asthma / epidemiology
  • Case-Control Studies
  • Humans
  • Industry / classification
  • Insurance Claim Review
  • Isocyanates / adverse effects
  • Isocyanates / analysis*
  • Multicenter Studies as Topic
  • Occupational Exposure / adverse effects
  • Occupational Exposure / analysis*
  • Ontario / epidemiology
  • Prevalence
  • Workers' Compensation / statistics & numerical data


  • Air Pollutants
  • Isocyanates