The acute toxicity of penta-, hexa-, and heptachlorohydroxydiphenyl ethers in mice

The acute intraperitoneal LD50 values of various hydroxychlorodiphenyl ethers (HO-ClX-DPEs; X = 5-7) in mice have been determined. The acute toxicities observed were on the order of, or slightly less than, that observed previously for 2-hydroxy-2',4,4'-trichlorodiphenyl ether (2-HO-Cl3-DPE; Irgasan DP-300; Triclosan), a commonly used bactericide. However, the acute toxicities determined for these compounds were substantially less than have been observed for HO-Cl9-DPEs and pentachlorophenol. The HO-ClX-DPEs had a marked hypothermic effect, similar to that produced by 2-HO-Cl3-DPE. Symptomatology following exposure to the HO-ClX-DPEs (X = 5-7) suggested a nonspecific depressant effect on the central nervous system.