49 C.F.R. § 173.2a
(a)
Classification of a material having more than one hazard. Except as provided in
paragraph (c) of this section, a material not specifically listed in the
§ 172.101 Table or assigned to an entry of articles containing hazardous materials (UN3537 to UN3548) that meets the definition of more than one hazard class or division as defined in this part, shall be classed according to the highest applicable hazard class of the following hazard classes, which are listed in descending order of hazard:
(1)
Class 7 (radioactive materials, other than limited quantities; and shipments of UN 3507, Uranium hexafluoride, radioactive material, excepted package)
(2)
Division 2.3 (poisonous gases).
(3)
Division 2.1 (flammable gases).
(4)
Division 2.2 (nonflammable gases).
(5)
Division 6.1 (poisonous liquids), Packing Group I, poisonous-by-inhalation only.
(6)
A material that meets the definition of a pyrophoric material in
§ 173.124(b)(1) of this subchapter (Division 4.2).
(7)
A material that meets the definition of a self-reactive material in
§ 173.124(a)(2) of this subchapter (Division 4.1).
(8)
Class 3 (flammable liquids), Class 8 (corrosive materials), Division 4.1 (flammable solids), Division 4.2 (spontaneously combustible materials), Division 4.3 (dangerous when wet materials), Division 5.1 (oxidizers) or Division 6.1 (poisonous liquids or solids other than Packing Group I, poisonous-by-inhalation). The hazard class and packing group for a material meeting more than one of these hazards shall be determined using the precedence table in
paragraph (b) of this section.
(10)
Class 9 (miscellaneous hazardous materials).
Notes, amendments, and revision history
Amendments
[Amdt. 173-224, 55 FR 52606, Dec. 21, 1990, as amended at 56 FR 66264, Dec. 20, 1991; Amdt. 173-241, 59 FR 67490, Dec. 29, 1994; Amdt. 173-247, 60 FR 48787, Sept. 20, 1995; Amdt. 173-244, 60 FR 50307, Sept. 28, 1995; 64 FR 10776, Mar. 5, 1999; 66 FR 33426, June 21, 2001; 66 FR 45182, 45379, Aug. 28, 2001; 68 FR 45032, July 31, 2003; 80 FR 1151, Jan. 8, 2015; 85 FR 27878, May 11, 2020]
Authority
Authority: 49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and 1.97.
Amendments
[Amdt. 173-224, 55 FR 52606, Dec. 21, 1990, as amended at 56 FR 66264, Dec. 20, 1991; Amdt. 173-241, 59 FR 67490, Dec. 29, 1994; Amdt. 173-247, 60 FR 48787, Sept. 20, 1995; Amdt. 173-244, 60 FR 50307, Sept. 28, 1995; 64 FR 10776, Mar. 5, 1999; 66 FR 33426, June 21, 2001; 66 FR 45182, 45379, Aug. 28, 2001; 68 FR 45032, July 31, 2003; 80 FR 1151, Jan. 8, 2015; 85 FR 27878, May 11, 2020]