Toxicology of Diethylene Glycol Butyl Ether 4. Dermal Subchronic/Reproduction Study in Rats

The subchronic and reproductive toxicity of diethylene glycol butyl ether (DGBE) by the dermal route was evaluated in Sprague-Dawley rats using a novel combined protocol. DGBE was administered dermally at 10 or 30% v/v in aqueous solutions or undiluted (100%) for 13 weeks under occlusion, 6 hr/day, 5 days/week at a maximum attainable volume of 2 mL/kg. Satellite groups of male and female rats were treated with the top dose of DGBE for 13 weeks, mated, and the females were treated through day 20 of gestation and allowed to deliver and nurse their offspring through day 21 of lactation (weaning). DGBE produced dermal irritation, which was dependent on concentration in incidence, severity, and time of onset and was more severe in females than in males. No corresponding histopathology was evident. The only suggestion of a systemic effect was a slightly increased incidence of urinary occult blood at study termination in the females receiving the 30% or 100% DGBE dose. There was no evidence of histopathologic changes in the testes, and vaginal cytology indicated no adverse effect on estrous cycling. There were no effects on reproductive performance of the DGBE-treated males and females. Litters delivered by treated females contained the same number of live pups as control litters and the growth and survival of pups within the treated litters was comparable to control. No reproductive or systemic toxicity was observed at the highest dose tested—2 g/kg/day.