49 C.F.R. § 173.2
Hazardous material classes and index to hazard class definitions.
Cite as 49 C.F.R. § 173.2 (2026)
The hazard class of a hazardous material is indicated by either the class or division number or the class name. The following table lists class numbers, division numbers, class or division names and those sections of this subchapter which contain definitions for classifying hazardous materials, including forbidden materials.
Table 1 to § 173.2
Class No.
Division
number
(if applicable)
Name of class or division
49 CFR reference for
definitions
None
FORBIDDEN MATERIALS
173.21
None
FORBIDDEN EXPLOSIVES
173.54
1
1.1
EXPLOSIVES (WITH A MASS EXPLOSION HAZARD)
173.50
1
1.2
EXPLOSIVES (WITH A PROJECTION HAZARD)
173.50
1
1.3
EXPLOSIVES (WITH PREDOMINATELY A FIRE HAZARD)
173.50
1
1.4
EXPLOSIVES (WITH NO SIGNIFICANT BLAST HAZARD)
173.50
1
1.5
VERY INSENSITIVE EXPLOSIVES; BLASTING AGENTS
173.50
1
1.6
EXTREMELY INSENSITIVE DETONATING SUBSTANCES
173.50
2
2.1
FLAMMABLE GAS
173.115
2
2.2
NON-FLAMMABLE COMPRESSED GAS
173.115
2
2.3
POISONOUS GAS
173.115
3
FLAMMABLE AND COMBUSTIBLE LIQUID
173.120
4
4.1
FLAMMABLE SOLID
173.124
4
4.2
SPONTANEOUSLY COMBUSTIBLE MATERIAL
173.124
4
4.3
DANGEROUS WHEN WET MATERIAL
173.124
5
5.1
OXIDIZER
173.127
5
5.2
ORGANIC PEROXIDE
173.128
6
6.1
POISONOUS MATERIALS
173.132
6
6.2
INFECTIOUS SUBSTANCE (ETIOLOGIC AGENT)
173.134
7
RADIOACTIVE MATERIAL
173.403
8
CORROSIVE MATERIAL
173.136
9
MISCELLANEOUS HAZARDOUS MATERIAL
173.140
[87 FR 79774, Dec. 27, 2022]
- Cross-references to the CFR
- 173.2