Chemical Hazard and Symbol

Chemical Hazard symbol divided into 9 categories class number of the dangerous characteristic of the chemicals. Each of category may describe different in every country.

Class 1: Explosive Materials


For example, the Canadian Transportation of Dangerous Goods Regulations provides a description of compatibility groups.
1.1 Explosives with a mass explosion hazard

• Ex: TNT, dynamite, nitroglycerin.

1.2 Explosives with a severe projection hazard.
1.3 Explosives with a fire, blast or projection hazard but not a mass explosion hazard.
1.4 Minor fire or projection hazard (includes ammunition and most consumer fireworks).
1.5 An insensitive substance with a mass explosion hazard (explosion similar to 1.1)
1.6 Extremely insensitive articles.

The United States Department of Transportation (DOT) regulates hazmat transportation within the territory of the US.

1.1 — Explosives with a mass explosion hazard. (nitroglycerin/dynamite)
1.2 — Explosives with a blast/projection hazard.
1.3 — Explosives with a minor blast hazard. (rocket propellant, display fireworks)
1.4 — Explosives with a major fire hazard. (consumer fireworks, ammunition)
1.5 — Blasting agents.
1.6 — Extremely insensitive explosives.

Class 2: Gasses

Gases which are compressed, liquefied or dissolved under pressure as detailed below. Some gases have subsidiary risk classes; poisonous or corrosive.

• 2.1 Flammable Gas: Gases which ignite on contact with an ignition source, such as acetylene and hydrogen.
• 2.2 Non-Flammable Gases: Gases which are neither flammable nor poisonous. Includes the cryogenic gases/liquids (temperatures of below -100°C) used for cryopreservation and rocket fuels, such as nitrogen and neon.
• 2.3 Poisonous Gases: Gases liable to cause death or serious injury to human health if inhaled; examples are fluorine, chlorine, and hydrogen cyanide.

Class 3: Flammable Liquids

Flammable liquids included in Class 3 are included in one of the following packing groups:

• Packing Group I, if they have an initial boiling point of 35°C or less at an absolute pressure of 101.3 kPa and any flash point, such as diethyl ether or carbon disulfide.
• Packing Group II, if they have an initial boiling point greater than 35°C at an absolute pressure of 101.3 kPa and a flash point less than 23°C, such as gasoline (petrol) and acetone.
• Packing Group III, if the criteria for inclusion in Packing Group I or II are not met, such as kerosene and diesel.

Class 4: Flammable Solids

• 4.1 Flammable Solids: Solid substances that are easily ignited and readily combustible (nitrocellulose, magnesium, safety or strike-anywhere matches).
• 4.2 Spontaneously Combustible: Solid substances that ignite spontaneously (aluminum alkyls, white phosphorus).
• 4.3 Dangerous when Wet: Solid substances that emit a flammable gas when wet or react violently with water (sodium, calcium, potassium, calcium carbide).

Class 5: Oxidizing Agents and Organic Peroxides

• 5.1 Oxidizing agents other than organic peroxides (calcium hypochlorite, ammonium nitrate, hydrogen peroxide, potassium permanganate).
• 5.2 Organic peroxides, either in liquid or solid form (benzoyl peroxides, cumenn hydroperoxide).

Class 6: Toxic and Infectious Substances

• 6.1a Toxic substances which are liable to cause death or serious injury to human health if inhaled, swallowed or by skin absorption (potassium cyanide, mercuric chloride).
• 6.1b (Now PGIII) Toxic substances which are harmful to human health (N.B this symbol is no longer authorized by the United Nations) (pesticides, methylene chloride).
• 6.2 Biohazardous substances; the World Health Organization (WHO) divides this class into two categories: Category A: Infectious; and Category B: Samples (virus cultures, pathology specimens, used intravenous needles).

Class 7: Radioactive Substances

Radioactive substances comprise substances or a combination of substances which emit ionizing radiation (uranium, plutonium).

Class 8: Corrosive Substances

Corrosive substances are substances that can dissolve organic tissue or severely corrode certain metals:

• 8.1 Acids: sulfuric acid, hydrochloric acid
• 8.2 Alkalis: potassium hydroxide, sodium hydroxide

Class 9: Miscellaneous

Hazardous substances that do not fall into the other categories (asbestos, air-bag inflators, self inflating life rafts, dry ice).

Other Hazardous Label: