ACETONE ODOR AND IRRITATION THRESHOLDS OBTAINED FROM ACETONE-EXPOSED FACTORY-WORKERS AND FROM CONTROL (OCCUPATIONALLY UNEXPOSED) SUBJECTS

Sensitivity of olfaction (smell) and chemesthesis (irritation) was eva luated for 2-propanone (acetone) and l-butanol in acetone-exposed work ers (AEW; N = 32) during a workday and unexposed subjects (mu ES; N = 32). Irritation sensitivity was assessed using a method that relies on the ability of individuals to localize irritants on the body. When a volatile compound is inhaled into one nostril and air into the other, the stimulated side can be determined (lateralized) only after the con centration reaches a level that stimulates the trigeminal nerve (irrit ation);compounds stimulating olfaction alone cannot be lateralized. In tranasal lateralization thresholds offer an objective measure of senso ry irritation elicited by volatile compounds. Test results indicated t hat neither olfactory nor lateralization thresholds for butanol differ ed between AEW and mu ES. Olfactory thresholds to acetone in AEW, (855 ppm) were elevated relative to those of mu ES (41 ppm), as were later alization thresholds (36,669 ppm and 15,758 ppm, respectively). Within AEW, level of occupational exposure-was not correlated with threshold s. Other measures revealed that mu ES used more irritation descriptors than did AEW on trials where the acetone concentration was below the lateralization threshold. This is noteworthy because mu ES received lo wer concentrations of acetone to evaluate than did AEW. These results suggest that exposures to acetone induce changes in acetone sensitivit y that are specific to acetone. The acetone concentrations eliciting s ensory irritation using the lateralization technique were all well abo ve current occupational exposure standards. The current study indicate s that acetone is a weak sensory irritant and that sensory adaptation is an important factor affecting its overall irritancy.