According to the Regulations on the Safety Management of Hazardous Chemicals (Order 591), hazardous chemicals refer to highly toxic chemicals and other chemicals that have toxic, corrosive, explosive, flammable, and combustible properties and pose a threat to human health, facilities, and the environment.

The "Catalogue of Hazardous Chemicals (2015 Edition)" stipulates the principles for determining hazardous chemicals: the types of hazardous chemicals are determined based on the national standards for chemical classification and labeling, from the following categories of hazardous and hazardous characteristics:

1. Physical hazards

Explosives: Unstable explosives, 1.1, 1.2, 1.3, 1.4.

Flammable gases: Category 1, Category 2, Chemical Unstable Gas Category A, Chemical Unstable Gas Category B.

Aerosol (also known as aerosol): Category 1.

Oxidative gas: Category 1.

Pressurized gases: compressed gases, liquefied gases, frozen liquefied gases, dissolved gases.

Flammable liquids: Category 1, Category 2, Category 3.

Flammable solids: Category 1, Category 2.

Self reactive substances and mixtures: Type A, Type B, Type C, Type D, Type E.

Spontaneous combustion liquid: Category 1.

Spontaneous combustion solid: Category 1.

Self heating substances and mixtures: Category 1, Category 2.

Substances and mixtures that release flammable gases when in contact with water: Class 1, Class 2, Class 3.

Oxidative liquids: Category 1, Category 2, Category 3.

Oxidative solids: Category 1, Category 2, Category 3.

Organic peroxides: Type A, Type B, Type C, Type D, Type E, Type F.

Metal corrosion: Category 1.

2. Health hazards

Acute toxicity: Category 1, Category 2, Category 3.

Skin corrosion/irritation: Category 1A, Category 1B, Category 1C, Category 2.

Serious eye injury/eye irritation: Category 1, Category 2A, Category 2B.

Respiratory or skin sensitization: Respiratory sensitizer 1A, respiratory sensitizer 1B, skin sensitizer 1A, skin sensitizer 1B.

Genital cell mutagenicity: Category 1A, Category 1B, Category 2.

Carcinogenicity: Category 1A, Category 1B, Category 2.

Reproductive toxicity: Category 1A, Category 1B, Category 2, Additional Category.

Specific target organ toxicity - single exposure: Category 1, Category 2, Category 3.

Specific target organ toxicity - repeated exposure: Category 1, Category 2.

Inhalation hazard: Category 1.

3. Environmental hazards

Hazard to aquatic environment - acute hazard: Category 1, Category 2; Harm to aquatic environment - Long term harm: Category 1, Category 2, Category 3.

Hazardous to the ozone layer: Category 1.