Alopecia induced by inhalation exposure to phenyl glycidyl ether

Rats and dogs were exposed to heated phenyl glycidyl ether (310 degrees C) vapor at average levels of 1.3, 5.0, and 11.8 ppm (v/v) for 6 hr/day, 5 days/wk, for 90 days. No adverse effects were observed in the dogs and rats other than alopecia in rats at the dose levels of 5.0 and 11.8 ppm. Microscopically, the skin lesions revealed slight acanthosis, hyperkeratosis, and occasional patchy parakeratosis in the epidermis. Follicular keratin plugs were observed with hyperkeratosis of epithelium in the hair follicles and sebaceous glands. Inflammatory reaction was mainly confined to the perifollicular region and affected the hair follicles, resulting in atrophy. The number of hair follicles in the resting stage appeared to increase. The hair shafts revealed impairment of keratinization and fragmentation. Extracted hairs showed an increase in the number of dystrophic follicles and constricted or broken hair shafts.