Acute Toxicity, Percutaneous Absorption and Effects on Hepatic Mixed Function Oxidase Activities of 2,4,4'-Trichloro-2'-hydroxydiphenyl Ether (Irgasan super( registered ) DP300) and Its Chlorinated Derivatives

Irgasan DP300 (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is used to prevent microbial attack on fabric and bacterial growth in skin and hair care products. In the presence of sodium hypochlorite, a common household bleaching agent, the compound forms three chlorinated derivatives that convert, along with the parent compound, to polychlorinated dibenzo-p-dioxins when exposed to heat or sunlight. In mice, the ip LD sub(50)s for the derivatives were related to the degree of chlorination, and the derivatives were more toxic than Irgasan DP300. The compounds were also easily absorbed percutaneously and demonstrated maximum tissue concentrations by 12 or 18 h. The derivatives also demonstrated induction of hepatic mixed function oxidase that was greater than induction produced by Irgasan DP300 and was comparable to induction produced by 3-methylcholanthrene or phenobarbital.