Transport of flammable liquids: ADR Class 3 dangerous goods.

The transport of flammable liquids requires special attention in the ADR transport of dangerous goods, due to the delicate nature of the substances involved.

The handling of these materials is complex and imposes the need not only to comply with safety regulations, but also to adopt advanced technologies and to have adequately trained personnel


ADR Class 3: flammable liquids


Flammable liquids, due to their hazardous nature, fall under Class 3 according to the ADR classification (European Agreement concerning the International Carriage of Dangerous Goods by Road). 

ADR Class 3 is specifically dedicated to flammable liquids and includes: 

  • liquid substances or mixtures of liquids with a flash point less than or equal to 60°C (F1); 
  • liquid substances and molten solid substances with a flash point above 60° and transported hot at temperatures equal to or above their flash point (F2);
  • liquid desensitised explosives (D), explosive substances dissolved or suspended in water or other liquid substances.

It is important to note that substances such as diesel and (light) fuel oil, which have a flash point above 60°C but not above 100°C; belong to this category.

ADR Class 3 groups also include: 

  • Flammable liquids, toxic (FT)
    • Toxic flammable liquids (FT1)
    • Pesticides (FT2)
  • Flammable liquids, corrosive (FC)
  • Flammable, toxic, corrosive liquids (FTC)


This subdivision provides a clear division of the various categories of flammable liquids according to their flammability, toxicity, corrosiveness and potential explosiveness. This classification is essential for the proper handling and safe transport of these materials, ensuring compliance with regulations and safe logistics operations.


Flash point in the transport of flammable liquids

The flash point is critical in the transport of flammable liquids, representing the temperature above which a liquid emits sufficient vapour to form a flammable mixture with air. A lower FP (Flash Point) increases the risk of vapour formation at normal temperatures. For example, petrol burns easily at normal temperatures with a flash point of -40º C, whereas diesel requires heating to +65º C.


The Class 3 Packing Group


Flammable liquids, classified in ADR Class 3 dangerous goods, are further subdivided by assignment to specific Packing Groups. These groups provide an indication of the degree of danger associated with the substances, thus helping to determine the safety measures and precautions required when transporting flammable liquids.

The Packaging Groups are:

  • Packing Group I - reserved for liquid substances that present a high hazard. Characteristics such as an initial boiling point less than or equal to 35º C make these substances particularly sensitive and require special care to ensure their safe transport.
  • Packaging Group II - comprises medium hazardous liquid substances with an initial boiling point above 35º C and a flash point below 23º C (in a closed container). Although these substances present a moderate risk, they still require careful handling to avoid hazardous situations.
  • Packaging Group III - includes liquid substances with a lower hazard rating, characterised by an initial boiling point above 35º C and a flash point between ≥ 23º C and ≤ 60º C. These substances are considered less hazardous, but appropriate precautions must still be taken during their transport.


This classification into Packing Groups allows those involved in the transport of flammable liquids to adopt specific approaches according to the degree of danger associated with each substance.


News in 2023 on the transport of flammable liquids


With the biennial update of the ADR Agreement in 2023 (link article), an important innovation was introduced regarding the extension of mandatory safety measures for all industrial vehicles transporting flammable gases and liquids. With this change, it becomes compulsory to equip such vehicles with automatic fire extinguishers in the engine compartment and thermal protection against wheel fires. These devices are designed to contain the spread of fire generated by the wheels themselves, representing a significant step forward in promoting safety during the transport of flammable liquids.


For the safe and reliable transport of flammable liquids, do not hesitate to contact Corsini, experts in the ADR sector for years. Our specialisation guarantees customised and regulation-compliant solutions for the transport of flammable liquids.