A SURVEY OF AIRBORNE HDI, HDI-BASED POLYISOCYANATE AND SOLVENT CONCENTRATIONS IN THE MANUFACTURE AND APPLICATION OF POLYURETHANE COATINGS

This study summarizes the results of industrial hygiene surveys perfor med between 1979 and 1987 in paint manufacturing and application opera tions using polyurethane coatings containing hexamethylene diisocyanat e (HDI) and HDI-based polyisocyanates (trade flame Desmodur N). A tota l of 466 Desmodur N and 457 HDI samples were collected from 47 operati ons most of which were in application. The application surveys covered manufacture and refinishing of transportation vehicles, painting of l arge military and civilian equipment, industrial finishing operations, and maintenance and construction operations. The primary objective of the surveys was to assess the potential exposure to HDI and HDI-based polyisocyanate. In more than 60% of the surveys, concentrations of ai rborne organic solvents also were monitored. Isocyanates were sampled using toluene/nitroreagent in midget impingers, and solvents were coll ected using charcoal tubes. They were analyzed using high pressure liq uid chromatography and gas chromatography, respectively. The data from these workplace situations show there is some potential for isocyanat e overexposure of unprotected workers and that it is greater in spray than in nonspray operations.