Abstract
The acute intraperitoneal LD50 values of various hydroxychlorodiphenyl ethers (HO‐ClxDPEs; 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‐CI 3 ‐DPE; irgasan DP‐300; Triclosan), a commonly used bactéricide. However, the acute toxicities determined for these compounds were substantially less than have been observed for HO‐CI,‐DPEs and pentachlorophenol. The HO‐CIxDPEs had a marked hypothermic effect, similar to that produced by 2‐HO‐Cl 3 ‐DPE. Symptomatology following exposure to the HO‐CIx DPEs (x = 5–7) suggested a nonspecific depressant effect on the central nervous system.