The transportation of dangerous goods is carried out using the following types of transport:

• Road (Automobile)
• Maritime
• Rail
• Air

For each mode of transportation, specific regulations and norms are established, including documentation, labeling and requirements for the accompanying cargo (e.g., how dangerous goods are transported). Such transportation demands comprehensive knowledge from service personnel about handling the cargo and adherence to safety protocols during emergencies, depending on the hazard class. The personnel must be properly trained and classified.

What Are the Hazard Classes for ADR Goods?

Any dangerous goods eligible for transportation are assigned a hazard class. There are nine main classes, each representing a different type of risk. Within each class, there are subcategories specific to the particular dangerous substances they encompass. 

Below, we will review each hazard class in more detail:

Class 1: Explosives (ADR – 1) 

Materials capable of causing explosions or fires, with the potential for pyrotechnic effects.

• Subcategories:
  • Substances causing mass explosions.
  • Substances causing localized fires or projection hazards without mass explosions.
  • Substances emitting radiant heat or minor explosive effects upon combustion.
  • Low-sensitivity explosives with minimal risk of transitioning from combustion to detonation.

Class 2: Gasses (ADR – 2)

Includes pure gasses, gas mixtures and compressed gasses at vapor pressures exceeding 300 kPa at 50°C.

• Hazard Types:
  • Asphyxiating gasses.
  • Toxic and corrosive gasses.
  • Flammable gases.
  • Non-flammable, non-toxic gasses.
  • Chemically unstable gasses.

Class 3: Flammable Liquids (ADR – 3)

Liquids with flashpoints below 61°C, including dissolved explosive substances. Examples: diesel fuel, light heating oil, gas oil and certain paints.

Class 4: Flammable Solids (ADR – 4)

Substances that ignite through friction, moisture absorption or heating. Includes self-reactive materials and pyrophoric substances that spontaneously combust.

• Subcategories:
  • Solids easily ignited by external factors.
  • Substances that emit flammable gasses when interacting with water.

Class 5: Oxidizing Substances and Organic Peroxides (ADR – 5)

Oxidizing agents that release oxygen to sustain combustion. Organic peroxides derived from hydrogen peroxide with explosive and flammable properties.

Class 6: Toxic and Infectious Substances (ADR – 6)

Toxic materials that can cause poisoning, disease or death upon ingestion, inhalation or skin contact. Includes infectious substances containing pathogens.

Class 7: Radioactive Materials (ADR – 7)

Goods emitting alpha, beta or gamma radiation. Hazards include burns, hair loss, blood disorders, cancer or death. Radioactive materials can also be corrosive and release heat.

Class 8: Corrosive Substances (ADR – 8)

Materials that corrode skin, mucous membranes and other surfaces upon contact. Examples: strong acids, alkalis and other highly corrosive agents.

Class 9: Miscellaneous Dangerous Goods (ADR – 9)

Other hazardous substances not covered in previous classes. Examples: fine dust harmful upon inhalation, devices emitting toxic fumes during combustion and highly flammable vapors.