MONITORING OCCUPATIONAL EXPOSURE TO ETHYLENE-OXIDE BY THE DETERMINATION OF HEMOGLOBIN ADDUCTS

In a study on workers in a chemical plant where ethylene oxide (EtO) i s manufactured and partly used for ethylene glycol production, exposur e to EtO was monitored during annual periodic health assessments in Ja nuary 1988, December 1988, and March 1990 by the determination of the level of 2-hydroxyethylvaline (HOEtVal) in hemoglobin. The HOEtVal lev els in workers corresponded with the potential EtO exposures. The high est level was found in December 1988, in blood samples collected 1-2 m onths after a shut-down, maintenance, and start-up program. The range of adduct levels found in the three examinations indicated that averag e EtO exposures during the 4 months preceding blood sampling were belo w 0.5 ppm. It was demonstrated that the method allows for the accurate monitoring of low levels of EtO exposure and provides personalized ti me-integrated exposure data with great discriminative power. In additi on, the method may serve to identify unexpected personal exposures, wh ich may lead to targeted exposure control measures.