Outbreak of asthma, rhinitis and skin symptoms in processing of polyvinyl chloride-polyurethane (PVC-PU) fabrics

Background: In a medium-sized company polyvinyl chloride-polyurethane (PVC-PU) –impregnated polyester fabrics are processed to canvas and tents by cutting and jointing with electric charge. Large areas of freshly-impregnated fabrics are handled, and the temperature of them rises up to about 140 degrees Celsius in the jointing process. Building ventilation system functioned insufficiently in 2016, when eight out of seventeen workers contacted their occupational physician due to respiratory or skin symptoms. Aim: To describe the respiratory and skin diseases of the workers and to assess exposure in the processing of PVC-PU fabrics. Methods: We investigated five exposed workers in 2016-2018. Exposure was assessed in 2017 by observations of the work processes and by measuring total dust, volatile organic compounds (VOC), toluene diisocyanate (TDI) and hydrochlorid acid in the air. Results: The work-related symptoms of all 5 workers had started in 2016. We diagnosed asthma in 4 workers. Rhinitis and skin symptoms occurred in 4 workers. Total VOC varied between 2200-4200 µg/m3, and they consisted mainly of solvents used in the production. Small traces of methyl methacrylate were identified. The concentrations of all other air impurities were very low. TDI concentrations were 0.01% and 0.04% of the occupational exposure limit (OEL) for isocyanates (35 ug/m3). The results indicated that the concentrations had not been near OEL during ventilation problems in 2016, either. Conclusions: Processing of PVC-PU fabrics is a potential health hazard for lungs. The rapid onset of symptoms refers to irritants at the workplace. Further investigations are ongoing to find out the causative agent.