TOXICOLOGY OF DIETHYLENE GLYCOL BUTYL ETHER .2. DISPOSITION STUDIES WITH C-14 DIETHYLENE GLYCOL BUTYL ETHER AND C-14 DIETHYLENE GLYCOL BUTYL ETHER ACETATE AFTER DERMAL APPLICATION TO RATS

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 do ses of C-14-DGBE and C-14-DGBA were determined in Sprague-Dawley rats. The materials were applied under occlusion for 24 hr at dose levels o f 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 ind icated that greater than 89% of each chemical could be removed from ra t skin following 5-min exposures. Female rats excreted a larger propor tion of the applied dose of DGBE than did male rats. Similar results w ere obtained with the low dose of DGBE applied neat or as a 10% aqueou s solution, suggesting that the low dose represents a saturating dose. The total recovered C-14 for all studies with C-14-DGBE ranged from 8 3% to 89%, with C-14-DGBA, from 80% to 88%. Urinary excretion accounte d for the majority of recovered C-14 in all studies. The acid, 2-(2-bu toxyethoxy)acetate acid was the major urinary metabolite identified. T he glucuronide of DGBE was present at levels of from 5.2 to 8.2% of th e urinary C-14. 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.