Combustible liquids

Scope

The classification of a material as a combustible liquid is strictly for transportation within the United States and is not recognized internationally.

Regulatory citations

• 49 CFR 173.120 — Class 3 Definitions
• 49 CFR 173.150 — Exceptions for Class 3 (flammable and combustible liquids)

Key definitions

• Bulk packaging: Other than vessels or barges, and including transport vehicles and freight containers, are packagings in which hazardous materials are loaded with no intermediate form of containment and which have:
  • A maximum capacity greater than 119 gallons (450 L) as a receptacle for a liquid;
  • A maximum net mass greater than 882 pounds (400 kg) and a maximum capacity greater than 119 gallons (450 L), as a receptacle for a solid; or
  • A water capacity greater than 1,000 pounds (454 kg), as a receptacle for a gas.
  • A Large Packaging in which hazardous materials are loaded with an intermediate form of containment, such as one or more articles or inner packagings, is also a bulk packaging.
• Combustible liquid: Any liquid that does not meet the definition of any other hazard class and has a flash point above 60 °C (140 °F) and below 93 °C (200 °F).
• Flammable liquid: A liquid having a flash point of not more than 60 °C (140 °F), or any material in a liquid phase with a flash point at or above 37.8 °C (100 °F) that is intentionally heated and offered for transportation or transported at or above its flash point in a bulk packaging, with the following exceptions:
  • Any liquid meeting one of the definitions specified in 173.115.
  • Any mixture having one or more components with a flash point of 60 °C (140 °F) or higher, that make up at least 99 percent of the total volume of the mixture, if the mixture is not offered for transportation or transported at or above its flash point.
  • Any liquid with a flash point greater than 35 °C (95 °F) that does not sustain combustion according to ASTM D 4206 (IBR, see 171.7) or the procedure in Part 173, Appendix H.
  • Any liquid with a flash point greater than 35 °C (95 °F) and with a fire point greater than 100 °C (212 °F) according to ISO 2592 (IBR, see 171.7).
  • Any liquid with a flash point greater than 35 °C (95 °F) which is in a water-miscible solution with a water content of more than 90 percent by mass.
• Flashpoint: The minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid.

Summary of requirements

Combustible liquid is defined in 173.120(b)(1) as “any liquid that does not meet the definition of any other hazard class specified in this subchapter [the Hazardous Materials Regulations], and that has a flashpoint above 60°C (140°F) and below 93°C (200°F).”