GB 5044-1985

This standard establishes a classification system for the health hazard levels posed by toxic substances in occupational settings, categorizing them into four grades (I through IV) based on factors like toxicity, exposure limits, and carcinogenicity. It is applied by Chinese industrial hygiene professionals and safety engineers to assess and manage risks in workplaces where employees handle chemicals, such as manufacturing plants, laboratories, and mining operations. The classification guides the implementation of protective measures, ventilation requirements, and medical surveillance programs to reduce occupational poisoning incidents.