4-WEEK REPEATED SKIN CONTACT STUDY WITH GLUTARALDEHYDE IN RATS

Glutaraldehyde (GA: CAS Number 111-30-8) is a widely used industrial c hemical and biocide from which skin contact may occur. The potential f or local and systemic toxicity by repeated skin contact was investigat ed in Fischer 344 rats using occluded epicutaneous applications of 2.5 , 5.0, and 7.5% aqueous GA solutions at a dose volume of 2.0 ml/kg/day , 6 h/day, for 20 applications over a 26 day period. This was equivale nt to 50, 100, and 150 mg GA/kg/day. Controls received filtered water at 2.0 ml/kg/day. There were no treatment-related mortalities or clini cal signs of systemic toxicity. Local skin irritation, mainly erythema and edema, was minimal and present only intermittently during the tre atment period, and resolved in 4-week recovery animals. There were sli ght decreases in body weight, body weight gain, and food consumption. A gender-related discrepancy in water consumption, apparently increase d in males and decreased in females, was probably related to proximity to the animal holding room air supply, with animals closest to the ai r intake having the greatest water consumption. Increases in platelet count, urea nitrogen, and adrenal gland weight, which generally resolv ed during a 4-week recovery period, were similar to the responses seen in other studies involving the recurrent epicutaneous application of irritant materials of various chemical classes to the rat. Histopathol ogical findings were restricted to areas of GA-treated skin: acanthosi s, dermatitis, hyperkeratosis, parakeratosis, epidermitis, and dermal fibrosis. Thus, in vivo shortterm recurrent application of GA solution s, up to 7.5%, to rat skin produced minimal skin irritation but no evi dence of systemic toxicity.