UN 9 Classes of Dangerous Goods Explained
Classes · Label Colors · Typical Cargo

The nine classes form the international framework for DG management. Once cargo is assigned to a class, it must be packaged, labeled and declared accordingly. This article explains the classification, label colors and typical cargo for each class.

Class 1: Explosives

Substances or articles that produce gas by chemical reaction, damaging surroundings through speed and pressure, or designed to produce explosive or pyrotechnic effects. Label: orange, explosion symbol. Subdivided into divisions 1.1 to 1.6:

• 1.1: mass explosion hazard
• 1.2: projection hazard but no mass explosion
• 1.3: fire hazard
• 1.4: no significant hazard
• 1.5: very insensitive explosive substances
• 1.6: extremely insensitive articles

Class 2: Gases

• 2.1 Flammable gases: LPG, hydrogen, acetylene - red label.
• 2.2 Non-flammable non-toxic gases: nitrogen, carbon dioxide, argon - green label.
• 2.3 Toxic gases: chlorine, ammonia, sulphur dioxide - white label with skull.

Class 3: Flammable Liquids

Liquids with a closed-cup flash point of 60 C or lower (or open-cup 65.6 C or lower). Examples: gasoline, ethanol, acetone, benzene, toluene. Label: red with flame.

Class 4: Flammable Solids; Pyrophoric; Water-Reactive

• 4.1 Flammable solids: sulphur, red phosphorus, metal powders - white with red stripes and flame
• 4.2 Pyrophoric substances: yellow phosphorus - upper white, lower red
• 4.3 Water-reactive substances: sodium, calcium - blue label

Class 5: Oxidizing Substances and Organic Peroxides

• 5.1 Oxidizing substances: potassium permanganate, ammonium nitrate - yellow label
• 5.2 Organic peroxides: benzoyl peroxide - upper red, lower yellow

Class 6: Toxic and Infectious Substances

• 6.1 Toxic substances: pesticides, cyanides - white with skull
• 6.2 Infectious substances: medical waste - white with biohazard symbol

Class 7: Radioactive Material

Substances emitting ionizing radiation above prescribed limits. Labels come in three types: I (white), II (yellow + white) and III (fully yellow); the higher the activity, the deeper the color.

Class 8: Corrosives

Substances that damage skin, mucous membranes or eyes through chemical action, or damage other cargo or conveyances if leaked, e.g. sulphuric acid, hydrochloric acid, sodium hydroxide, glacial acetic acid. Label: black/white, liquid corroding metal and hand.

Class 9: Miscellaneous Dangerous Goods

Substances posing a transport hazard but not meeting other class definitions, including:

• Lithium batteries (UN3480 / UN3481 / UN3090 / UN3091)
• Dry ice / solid carbon dioxide (UN1845)
• Magnetized material (UN2807)
• Airbags (UN3268)
• Environmentally hazardous substances

Label: white with black vertical stripes.