I. Laws Related to Hazardous Chemicals

1. The principal person in charge of a production and business entity shall bear overall responsibility for the entity’s work on production safety.—Article 5 of the “Production Safety Law”

2. Anyone who violates regulations on safety management during production or operations, thereby causing a serious injury or death accident or other grave consequences, shall be sentenced to imprisonment of no more than three years or detention. In cases involving particularly egregious circumstances, the offender shall be sentenced to imprisonment of more than three years but no more than seven years.—Article 134 of the Criminal Law

3. Anyone who violates the regulations governing the management of explosive, flammable, radioactive, toxic, or corrosive substances and causes a serious accident during production, storage, transportation, or use, resulting in grave consequences, shall be sentenced to a fixed-term imprisonment of no more than three years or criminal detention. If the consequences are particularly severe, the offender shall be sentenced to a fixed-term imprisonment of more than three years but less than seven years.—Article 136 of the Criminal Law

II. What are Hazardous Chemicals?

Hazardous chemicals refer to substances that are flammable, explosive, toxic, harmful, or radioactive—materials that pose a significant risk of causing casualties and property damage during transportation, loading and unloading, and storage and custody, thus requiring special protection.

III. Classification of Hazardous Chemicals

(1) Explosives; (2) Compressed gases and liquefied gases; (3) Flammable liquids; (4) Flammable solids, flammable substances, and substances that become flammable upon contact with moisture; (5) Oxidizers and organic peroxides; (6) Toxic substances and infectious substances; (7) Radioactive materials; (8) Corrosive substances.

1. Explosives

An item that, under external influence, undergoes a violent chemical reaction, instantly generating large amounts of gas and heat, causing a rapid increase in surrounding pressure, resulting in an explosion and damage to the surrounding environment.

(1) Substances and articles with an overall explosive hazard, such as perchloric acid.

(2) Substances and articles that pose a projection hazard but do not have a general explosive hazard.

(3) Substances and articles that pose a fire hazard and have either a minor explosion hazard or a minor projection hazard, or both, but do not present an overall explosion hazard—such as dinitrobenzene.

(4) Explosive substances and items that pose no significant hazard, such as tetra-1-acetate.

(5) Highly insensitive explosive substances

2. Compressed gases and liquefied gases

Compressed, liquefied, or pressurized dissolved gases

(1) Flammable gases: such as ammonia, carbon monoxide, methane, etc.

(2) Non-combustible gases: such as nitrogen, oxygen, etc.

(3) Toxic gases: such as chlorine (liquefied), ammonia (liquefied), etc.

3. Flammable liquids

It is highly volatile, and its vapor, when mixed with air, can form an explosive mixture. Its closed-cup flash point is equal to or below 61°C.

(1) Low-flashpoint liquids: liquids with a flashpoint below -18℃, such as acetaldehyde and acetone.

(2) Liquids with a flash point between -18°C and <23°C, such as benzene and methanol.

(3) High-flashpoint liquids; flashpoints ranging from 23°C to 61°C, such as cyclooctane and anisole.

4. Flammable solids, self-heating substances, and substances that become flammable upon contact with moisture

(1) Flammable solids: Solids with a low ignition point that are sensitive to heat, impact, and friction, easily ignited by external sources of ignition, burn rapidly, and can emit toxic fumes or toxic gases. Examples include red phosphorus and sulfur.

(2) Self-igniting substances: These are substances with a low ignition point that readily undergo oxidation reactions in air, releasing heat and spontaneously igniting. Examples include yellow phosphorus and titanium trichloride.

(3) Water-reactive flammable substances: These substances undergo a violent reaction when exposed to water or moisture, releasing large quantities of flammable gases and heat. Some can even ignite or explode without an external ignition source. Examples include metallic sodium and potassium hydride.

5. Oxidizers and organic peroxides

(1) Oxidizing agents: Substances with strong oxidizing properties that readily decompose, releasing oxygen and heat, and are relatively sensitive to heat, shock, and friction. Examples include ammonium chlorate and potassium permanganate.

(2) Organic peroxides: Organic compounds whose molecular structure contains an peroxy bond. These substances are highly flammable and explosive, extremely prone to decomposition, and highly sensitive to heat, shock, and friction. Examples include benzoyl peroxide and methyl ethyl ketone peroxide.

6. Toxic substances and infectious materials

(1) Toxic substances: After entering the body and accumulating to a certain level, these substances can interact biochemically or biophysically with body fluids and tissues, disrupting or impairing the body’s normal physiological functions, causing temporary or persistent pathological conditions, and even posing a threat to life—for example, various cyanides, arsenides, and chemical pesticides.

(2) Infectious substances: Substances containing pathogenic microorganisms that can cause illness or even death, such as the avian influenza virus and the SARS virus.

7. Radioactive materials

Radioactive materials refer to substances with a specific activity exceeding 7.4 × 10⁴ Bq/kg.

It is classified as a hazardous chemical, but it does not fall under the scope of management stipulated by the “Regulations on the Safety Management of Hazardous Chemicals.” Instead, the state has separate, specialized “regulations” specifically designed to govern it.

8. Corrosive substances

A solid or liquid that can burn human tissue and cause damage to objects such as metals.

(1) Acidic corrosives: such as sulfuric acid, nitric acid, and hydrochloric acid.

(2) Alkaline corrosives: such as sodium hydroxide and calcium hydrosulfide, etc.

(3) Other corrosive substances: such as dichloroacetaldehyde and sodium phenolate, etc.

IV. Hazardous Chemical Labels

1. Explosives

2. Flammable liquids, flammable gases

3. Flammable solids

4. Substances that are easily combustible

5. Oxidizing agent

6. Organic peroxides

7. Compressed gas or liquefied gas (non-flammable)

8. Toxic substances

9. Infectious substances

10. Radioactive substances

11. Corrosive substances

12. Respiratory allergens, carcinogens, and reproductive toxins

13. Substances harmful to the aquatic environment

14. Acute toxicity, skin irritation, eye irritation, skin sensitization

15. Moisture-reactive flammable substances

V. Storage of Hazardous Chemicals

According to the fire protection code for building design based on fire hazard levels, buildings are classified into five categories.

(1) Class A: 6 characteristic features; (2) Class B: 6 characteristic features; (3) Class C: 2 characteristic features; (4) Class D: Hard-to-burn materials; (5) Class E: Non-combustible materials

1. Class A Hazardous Chemicals

(1) Liquids with a flash point below 28℃. For example, acetone has a flash point of -20℃.

(2) Gases with a lower explosive limit (LEL) of less than 10%, as well as solid substances that can produce explosions upon exposure to water or water vapor in the air—such as methane, which has an LEL of 5%—are classified accordingly.

(3) Substances that can decompose spontaneously at room temperature or oxidize in air, leading to rapid self-detonation or explosion, such as nitrocellulose and yellow phosphorus.

(4) Substances that, under normal temperature conditions, react with water or water vapor in the air to produce flammable gases and can cause combustion or explosion. Examples include metallic sodium and metallic potassium.

(5) Strong oxidizers that readily undergo combustion or explosion upon contact with acids, heat, impact, friction, or inorganic substances that are easily flammable when exposed to organic materials or sulfur. Examples include potassium chlorate and sodium chlorate.

(6) Substances that can ignite or explode upon impact, friction, or contact with oxidizers or organic materials. Examples include phosphorus pentasulfide and phosphorus trisulfide.

2. Class II Hazardous Chemicals

(1) Liquids with a flash point ≥28℃ and <60℃, such as acrylic acid with a flash point of 54℃.

(2) Gases with a lower explosive limit greater than 10%, such as ammonia and liquid ammonia.

(3) Oxidizing agents that do not belong to Class A, such as sodium dichromate and potassium chromate.

(4) Flammable solid chemicals that do not belong to Class A, such as sulfur and industrial naphthalene.

(5) Combustion-supporting gases, such as oxygen.

(6) Substances that can slowly oxidize upon contact with air at room temperature and, due to the accumulation of heat that cannot dissipate, may spontaneously ignite.

3. Class C Hazardous Chemicals

(1) Liquids with a flash point ≥ 60℃. For example, cyclohexanone has a flash point of 63.9℃, and hydroxyethyl acrylate has a flash point of 99℃.

(2) Combustible solids, such as natural rubber and its products.

4. Three methods for storing various hazardous chemicals

(1) Isolation: Separate buildings. Explosives, compressed gases, and liquefied gases.

(2) Separation: Different rooms within the same building. Toxic substances, corrosives, flammable solids, oxidizers, and organic peroxides.

(3) Separation: Same building, same room. Flammable liquids.

VI. Firefighting Measures for Hazardous Chemicals

1. Basic methods for extinguishing fires involving flammable liquids:

(1) Insoluble in water

a. These substances are lighter than water and insoluble in water; examples include petroleum, gasoline, kerosene, and diesel oil. They can be extinguished using fire-extinguishing agents such as foam, dry powder, and halogenated hydrocarbons. When the fire is just starting, the area involved is small, or there is not much combustible material, carbon dioxide can be used for suppression.

b. For flammable liquids that are insoluble in water and have a specific gravity greater than water—such as carbon disulfide—if they catch fire, they can be extinguished with water.

(2) Soluble in water

For flammable liquids that are soluble in water or partially soluble in water—such as formaldehyde and alcohols like ethanol—when they catch fire, extinguishing agents such as misty water, resistant foam, dry powder, and halogenated hydrocarbons can be used for firefighting.

2. Precautions when a corrosive substance catches fire:

In the event of a fire involving corrosive substances, it is generally advisable to use foggy water or dry sand, foam, or dry powder for extinguishing the fire. High-pressure water should be avoided to prevent splashing of acidic liquids that could injure firefighters. When fires involve substances such as sulfuric acid, halides, or strong alkalis—substances that generate heat, decompose, or produce acidic fumes upon contact with water—water should not be used for firefighting. Instead, dry sand, foam, or dry powder can be employed. Firefighters must take precautions against corrosion and toxic gases by wearing gas masks, goggles, or respirators, donning rubber raincoats and tall rubber boots, and putting on corrosion-resistant gloves. During firefighting operations, personnel should stand upwind. If a person is found to be poisoned, they should be immediately taken to a hospital for emergency treatment, and the name of the poisonous substance involved should be clearly reported to enable doctors to provide appropriate medical care.

3. Precautions when an organic peroxide catches fire:

When organic peroxides catch fire or are caught in a blaze, they may explode. Therefore, these packages should be promptly removed from the fire area, and personnel should stay as far away from the fire as possible. Use large quantities of water to extinguish the fire from a protected position. Any package containing organic peroxides that has been involved in a fire or exposed to high temperatures—even after the fire has been put out—may undergo violent decomposition at any time before the package has completely cooled down. If feasible, such packages should be handled under the technical guidance of qualified professionals. If such guidance is unavailable, and during water transport, in case of emergency, consider discarding these packages into the water.

Finally, a reminder to everyone:

Safety first, prevention is key.