Biological monitoring of workers exposed to carbon disulfide

Urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) concentrations and corresponding personal breathing zone carbon disulfide (CS2) air concentrations were measured for worker populations at a Tennessee rubber product facility and a Virginia viscose rayon plant. At the rubber product facility, all of the 19 workers had urinary TTCA levels less than the limit of detection (LOD) of about 0.03 mg/L, equivalent to less than 0.5 ppm of CS2 in air. At the viscose rayon plant, five of six workers, although wearing half-mask cartridge respirators, showed increased urinary TTCA during the workshift. The cutters and spinners had the largest increases in urinary TTCA concentrations; they also had the highest breathing zone exposures to CS2. The TTCA concentrations for three cutters and spinners did not return to normal preshift levels of < 0.3 mg/g creatinine before the start of the next shift. The arithmetic mean respirator workplace protection factor (WPF) was 7.0 +/- 2.2. Increase in urinary TTCA concentration during the workshift and postshift urinary TTCA concentration reflected CS2 air concentration equally well. In conjunction with air monitoring results, urinary TTCA concentrations allow determination of the WPF afforded workers wearing respirators and identify workers not adhering to safety rules and good work practices. Workers at risk of adverse health effects from overexposure to CS2 for any reason may thus be identified.