According to GOST 12.1.007 RS-421 is considered a moderately hazardous substance and belong to 3 hazard class. Toxic, flammable liquid with a flash point of 6 to 12°C depending on the formulation. In terms of the degree of impact on the human body it belongs to the 3 hazard class substances according to GOST 12.1.007-76 (moderate hazard). Contact with this chemical may result in a local irritation of skin, eyes, and respiratory tract.