Design and Laboratory Evaluation of a Breath Sampling Respirator for Organic Solvent Biological Monitoring

Abstract A modified half-face air purifying respirator was developed as a technique for large-scale monitoring that will be acceptable to workers, simple to apply, and relatively sensitive. Exhaled air was directed through the respirator exhaust port and then through a two-part cartridge. The first part contained four layers of activated charcoal cloth which adsorbed organic solvent vapors; the cloth was subsequently desorbed for standard gas chromatographic analysis. The second part contained 70 g of 8–12 mesh molecular sieve whose weight gain was proportional to the volume of air exhaled. The proportionality was determined by independent measurement of volume in subjects while at rest and while exercising. Controlled atmospheres containing toluene at relative humidities near saturation were passed through the cartridge at steady flows equal to resting human ventilatory rates. Toluene recovery was 70 percent for simulated breath concentrations of 0.75 mg/m3 to 60 mg/m3. Nine adult males volunteered to br...