Abstract
Time-weighted average styrene and noise exposures were assessed for a cohort of 256 workers taken from 13 glass fiber-reinforced plastics manufacturing plants in Canada using conventional methods. Statistically significant differences existed in styrene exposures between the plants, although only 11 percent of the subjects had measured exposures in excess of 50 ppm (213 mg/m3). Few subjects reported using respiratory protection. Open/contact molding techniques were associated with higher exposures than closed molding processes, with those using chopper guns, involved in grid manufacture, and doing manual hand layup in confined spaces having the highest exposures. No differences were observed in styrene exposures between filament winding for pipes less than 0.75 m in diameter compared with large tanks (up to 2 m in diameter) wound on mandrels. The styrene exposures were consistent with, or slightly lower than, those reported in the literature. Individual noise exposures ranged from 70 to 105 dBA, with 97 (38%) of the subjects having exposures in excess of 90 dBA. Of these 97 subjects, only 27 percent reported using hearing protection constantly, and 22 percent reported never using such protection. Grid manufacture and assembly work were associated with the highest noise exposures as a consequence of grinding and sawing operations.