The benzenediols: catechol, resorcinol and hydroquinone--a review of the industrial toxicology and current industrial exposure limits.

A review of the published industrial toxicology for the benzenediols, catechol, resorcinol and hydroquinone was made to evaluate their proposed or established occupational exposure levels. Acute animal toxicity data for catecholand resorcinol are presented, along with that for phenol because of its analogous signs of illness and intoxication. The comparative acute toxicity data for catechol and phenol are anomalous, but suggest a TLV for catechol similar to that of phenol. The comparative acute toxicity data for resorcinol and phenol clearly show that resorcinol is significantly less toxic than phenol which has a 5 ppm TLV. These data, along with production plant exposures as high as 9.6 ppm without reported effects, suggest an industrial exposure level (TLV) for resorcinol of at least 10 ppm, perhaps 20 ppm or higher. The established 2 mg/M3 TLV for hydroquinone appears to be proper.