As a result of the industrial purification of hydrocarbons from mercaptans, tens of thousands of tons of dialkyl disulphides and their mixtures, the toxicity and hazard of which has not been fully understood, are accumulated annually. The exposure standards have been developed only for dimethyl disulphide. The study was aimed to define toxicometry parameters for diethyl disulphide, disulphide oil, and the mixture of dialkyl disulphides. Toxicology studies involving male outbred rats made it possible to define the median lethal doses and concentrations: diethyl disulphide — after intragastric injection DL₅₀ = 1575 mg/kg, after the 4-hour inhalation exposure CL₅₀ = 18,700 mg/m³, after intraperitoneal injection DL₅₀ = 1134 mg/kg, and after skin application DL₅₀ ˃ 2500 mg/kg; mixture of dialkyl disulphides — after intragastric injection DL50 = 428 mg/kg, after the 4-hour inhalation exposure CL₅₀ = 4510 mg/m³, after intraperitoneal injection DL₅₀ = 212 mg/kg, and after skin application DL₅₀ ˃ 2500 mg/kg; disulphide oil — after intragastric injection DL₅₀ = 448 mg/kg, after the 4-hour inhalation exposure CL₅₀ = 4534 mg/m³, after intraperitoneal injection DL₅₀ = 156 mg/kg, and after skin application DL₅₀ ˃ 2500 mg/kg. The hazard assessment for dialkyl disulphides and their mixtures was performed.