Experimental Human Exposure to Trichloroethylene

Ten experimental human exposures to frichloro-ethylene vapor, 100 and 200 ppm, for periods of one hour to a five-day work week were conducted. At 200 ppm, untoward subjective responses were mild, inconsistently present, and of doubtful clinical significance. The only troublesome response was a sensation of mild fatigue and sleepiness in five subjects during their fourth and fifth consecutive days of exposure to 200 ppm. Analysis of expired breath of humans by infrared or gas chromatographic techniques provided a means by which to unequivocally establish a diagnosis of exposure. Serial measurements of the solvent present breath in the postexposure period provided the data from which to construct a family of breath excretion curves useful in estimating the magnitude of exposure. Measurement of urinary metabolites of trichloroethylene proved to be an unsatisfactory index of exposure.