The sanitary condition of milking equipment and dairy equipment is one of the main factors on which the quality and, primarily, the safety of the obtained products depend. According to the approved requirements, means for the sanitary treatment of milking equipment must have a broad antimicrobial spectrum, high bactericidal activity both in the absence and presence of organic substances and water hardness salts, destroy microorganisms that can form a biofilm, and are present in it, not cause an irritating effect on the skin of the hands, be non-toxic or low-toxic, etc. Therefore, to establish the disinfectant's compliance with the specified requirements, even at the stage of its development, it is envisaged to carry out toxicological studies aimed at determining toxicity, side effects, and the ability to accumulate in the body. Our work aimed to establish the toxicity parameters of the developed acidic detergent-disinfectant with polyhexamethyleneguanidine intended for the sanitary-hygienic treatment of milking equipment and dairy equipment. Indicators of acute toxicity of the developed disinfectant were determined in preliminary and extensive experiments. In a preliminary experiment, it was established that the administration of the native remedy to rats at a dose of 500, 1000, and 2000 mg/kg of body weight did not cause their death, while at a dose of 5000 mg/kg of body weight, it caused the death of the animals. In an acute experiment, it was established that the studied detergent-disinfectant based on orthophosphate acid with polyhexamethyleneguanidine at a dose of 2000 mg/kg of body weight did not cause the death of rats, while at a dose of 2500 mg/kg of body weight, it caused the death of 1 animal, at a dose of 3000 mg/kg – 2 animals, and in doses of 3500, 4000 and 4500 mg/kg of body weight – 4, 5 and 6 animals, respectively. Examining the acute toxicity of a 0.5 % solution of the studied disinfectant in doses of 1000, 2000, 3000, 4000, and 5000 mg/kg of body weight in a focused experiment and 5000 and 10000 mg/kg of body weight in an extended experiment, it was established that there were no dead or sick rats. It has been proven that, according to SOU 85.2-37-736:2011, the substance under study belongs to the IV toxicity class, which combines low-toxic substances, since its DL50 in its native form for white rats with intragastric administration is more than 3250 mg/kg of body weight, and 0.5 % solution – more than 10,000 mg/kg of body weight. In its native form, the developed disinfectant causes slight irritation of the skin and mucous membrane of the eyes of rabbits. At a concentration of 0.5 %, it has no irritating effect. The tool does not accumulate in the body, has no resorptive effect, and does not cause probable changes in the mass of internal organs. With long-term intragastric administration, it causes an increase in the number of leukocytes, hemoglobin and total protein, ALT, and AST activity (P < 0.001) and a decrease in the number of lymphocytes, monocytes, lipids and triglycerides, hematocrit value, alkaline phosphatase activity, lysozyme, and bactericidal activity.