Definitions

Scope

Anyone using the Hazardous Materials Regulations (HMR) must understand the words or terms used within the HMR. The HMR includes sections that explain the definitions and terms to help users better understand the regulations.

Regulatory citations

• 49 CFR 171.8 — Definitions and abbreviations

Key definitions

• Bulk packaging: A packaging (other than a vessel or a barge) with no intermediate form of containment and having a:
  • maximum capacity greater than 450 L (119 gallons) as a receptacle for a liquid;
  • maximum net mass greater than 400 kg (882 pounds) and a maximum capacity greater than 450 L (119 gallons) as a receptacle for a solid; or
  • water capacity greater than 450 kg (1000 pounds) as a receptacle for a gas as defined in 173.115.
• Hazardous material: A substance or material which has been determined by the Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce.
• Hazardous substance: A material, including its mixtures and solutions, that:
  • Is listed in Appendix A to 172.101; and
  • Is in a quantity in one package that equals or exceeds the reportable quantity listed in the Appendix; and
  • When in a mixture or solution is in a concentration indicated in the table in 171.8.
  These materials have been so designated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
• Non-bulk packaging: Is a packaging which has:
  • A maximum capacity of 450 L (119 gallons) or less as a receptacle for a liquid,
  • A maximum net mass of 400 kg (882 pounds) or less and a maximum capacity of 450 L (119 gallons) or less as a receptacle for a solid,
  • A water capacity of 454 kg (1000 pounds) or less as a receptacle for a gas, or
  • Regardless of the definition of bulk packaging, a maximum net mass of 400 kg (882 pounds) or less for a bag or a box conforming to the applicable requirements for specification packagings, including the maximum net mass limitations, provided in Subpart L of Part 178.

Summary of requirements

In general, definitions of most words and phrases used in the regulations are given in 171.8, referenced elsewhere, or both. To illustrate the latter, hazard class definitions are listed in two ways in 171.8: by their class and/or by name, e.g., “Class 3” and “flammable liquid,” and then the reader is referred to Part 173.

Rules of construction.

• Shall and must are used in the imperative sense (mandatory).
• Should and may are used in the recommendatory or permissive sense, respectively (not mandatory).
• Singular includes the plural, and, vice versa: the plural includes the singular, unless the context requires otherwise.