Exposure to Styrene in Fibreglass-Reinforced Plastic Manufacture: Still a Problem

In this study, the authors defined occupational exposure to styrene in fibreglass manufacturing and investigated its effects. The phase of stretching styrene resins requires some manual handling and leads workers to be exposed to styrene. During the study, 20 workers were surveyed in two companies manufacturing fibreglass, checking environmental levels and urinary concentrations of mandelic acid (MA), and phenylglyoxylic acid (PGA). Workers completed a questionnaire collecting their medical history. Environmental monitoring showed some styrene concentrations higher than the threshold limit value-time-weighted average. Biological monitoring confirmed these findings and four workers had levels of urinary PGA and MA concentrations higher than the biological exposure indexes of the American Conference of Governmental Industrial Hygienists. This picture confirms that, even though the risk is known and the manufacturing cycle is well defined, workers nevertheless risk exposure. More research is needed to optimise the work processes and the protection systems to lower this risk.