A sample of 1,2-Benzenediol, mixture with methanol (22:78), also known as catechol in methanol (22:78) and identified as reference number 2, was submitted for acute toxicologic evaluation. The source of this clear liquid was the Central Research Engineering Department, Dow Chemical Company, Midland, MI. The test material is of interest. Acute oral toxicity testing was conducted with Fischer 344 rats (Charles River Breed- ing Laboratories, Inc., Kingston, NY). Eye and skin irritation tests and acute percutaneous absorption tests were conducted with New Zealand White rabbits (Hazleton-Outchland, Inc., Denver, PA). The acute oral toxicity of the test material was low. Range-finding tests indicated the oral LD50 for sale rats was approximately 1000 mg/kg. Rats received the undiluted material at the following dose levels (number dead/number treated in parentheses): 500 (0/3), 1000 (1/3), or 3000 (3/3) mg/kg. In-life signs of toxicity included convulsions/tremors (1000, 3000 mg/kg), and rapid shallow respiration (500, 1000 mg/kg). Other observations, seen in the 1000 mg/kg dose group only, included lacrima- tion, lethargy, palpebral closure, and excessive salivation. All survivors steadily gained weight during the two week observation period. Non-specific findings were observed upon necropsy of one rat from the 1000 mg/kg group that died spontaneously. No target organs were identified upon necropsy of rats surving the testing period. Undiluted test material was instilled into the conjunctival sacs (eyes) of a male rabbit at a dosage of 0.1 ml/eye. The single exposure resulted in very slight to slight discomfort, marked conjunctival redness and swelling, moderate reddening of the iris, moderate corneal cloudiness, and vascularization of the corneal surfaces. Ocular effects were still present in both eyes 21 days after exposure.