Toxicology of Diethylene Glycol Butyl Ether 2. Disposition Studies with 14C-Diethylene Glycol Butyl Ether and 14C-Diethylene Glycol Butyl Ether Acetate After Dermal Application to Rats

Abstract

Human dermal exposure to diethylene glycol butyl ether (DGBE) and its acetate derivative (DGBA) may occur through contact with a variety of commercial products. Absorption and elimination of dermally applied doses of 14C-DGBE and 14C-DGBA were determined in Sprague-Dawley rats. The materials were applied under occlusion for 24 hr at dose levels of 0.2 and 2.0 g/kg (undiluted) and as a 10% aqueous solution (0.2 g/kg DGBE). Preliminary washing efficiency studies with soap and water indicated that greater than 89% of each chemical could be removed from rat skin following 5-min exposures. Female rats excreted a larger proportion of the applied dose of DGBE than did male rats. Similar results were obtained with the low dose of DGBE applied neat or as a 10% aqueous solution, suggesting that the low dose represents a saturating dose. The total recovered 14C for all studies with 14C-DGBE ranged from 83% to 89%, with 14C-DGBA, from 80% to 88%. Urinary excretion accounted for the majority of recovered 14C in all studies. The acid, 2-(2-butoxyethoxy)acetate acid was the major urinary metabolite identified. The glucuronide of DGBE was present at levels of from 5.2 to 8.2% of the urinary 14C. The dermal absorption rates were estimated to be 1.58 (DGBA, male), 1.28 (DGBA, female), 0.73 (DGBE, male), and 1.46 (DGBE, female), expressed as mg/cm2/hr.