政策法规现行有效美国危险品合规

§ 173.2a Classification of a material having more than one hazard.

效力	法规类型	发布日期	生效日期	发文机构
现行有效	部门规章	2026-08-07	2026-09-08	Code of Federal Regulations (CFR) - Transportation (Title 49)

发布08-07

生效09-08

摘要总结AI 辅助解读

本条款规定了具有多重危险特性的物质在美国运输中的分类优先级规则。除特定例外（如爆炸品、有机过氧化物等），未列名且符合多种危险类别定义的货物，须按最高危害等级进行分类。优先级顺序为：第7类放射性 > 2.3毒性气体 > 2.1易燃气体 > 2.2非易燃气体 > 6.1 I级吸入毒性液体 > 自燃/自反应物质 > 其他常见类别（3, 4, 5, 6, 8类）。对于同时涉及第3类和第8类等常见混合危险货物，需依据具体的“危害优先表”确定主危和副危及包装组别。该规则直接决定申报代码、标签粘贴及隔离要求。

(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.

- (9) Combustible liquids.

- (10) Class 9 (miscellaneous hazardous materials).

(b) Precedence of hazard table for Classes 3 and 8 and Divisions 4.1, 4.2, 4.3, 5.1 and 6.1. The following table ranks those materials that meet the definition of Classes 3 and 8 and Divisions 4.1, 4.2, 4.3, 5.1 and 6.1:

Precedence of Hazard Table [ Hazard class or division and packing group ] 4.2 4.3 5.1 I 1 5.1 II 1 5.1 III 1 6.1, I dermal 6.1, I oral 6.1 II 6.1 III 8, I liquid 8, I solid 8, II liquid 8, II solid 8, III liquid 8, III solid 3 I 2 4.3 3 3 3 3 3 ( 3 ) 3 ( 3 ) 3 ( 3 ) 3 II 2 4.3 3 3 3 3 8 ( 3 ) 3 ( 3 ) 3 ( 3 ) 3 III 2 4.3 6.1 6.1 6.1 3 4 8 ( 3 ) 8 ( 3 ) 3 ( 3 ) 4.1 II 2 4.2 4.3 5.1 4.1 4.1 6.1 6.1 4.1 4.1 ( 3 ) 8 ( 3 ) 4.1 ( 3 ) 4.1 4.1 III 2 4.2 4.3 5.1 4.1 4.1 6.1 6.1 6.1 4.1 ( 3 ) 8 ( 3 ) 8 ( 3 ) 4.1 4.2 II 4.3 5.1 4.2 4.2 6.1 6.1 4.2 4.2 8 8 4.2 4.2 4.2 4.2 4.2 III 4.3 5.1 5.1 4.2 6.1 6.1 6.1 4.2 8 8 8 8 4.2 4.2 4.3 I 5.1 4.3 4.3 6.1 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 4.3 II 5.1 4.3 4.3 6.1 4.3 4.3 4.3 8 8 4.3 4.3 4.3 4.3 4.3 III 5.1 5.1 4.3 6.1 6.1 6.1 4.3 8 8 8 8 4.3 4.3 5.1 I 1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 II 1 6.1 5.1 5.1 5.1 8 8 5.1 5.1 5.1 5.1 5.1 III 1 6.1 6.1 6.1 5.1 8 8 8 8 5.1 5.1 6.1 I, Dermal 8 6.1 6.1 6.1 6.1 6.1 6.1 I, Oral 8 6.1 6.1 6.1 6.1 6.1 6.1 II, Inhalation 8 6.1 6.1 6.1 6.1 6.1 6.1 II, Dermal 8 6.1 8 6.1 6.1 6.1 6.1 II, Oral 8 8 8 6.1 6.1 6.1 6.1 III 8 8 8 8 8 8 1 See § 173.127. 2 Materials of Division 4.1 other than self-reactive substances and solid desensitized explosives, and materials of Class 3 other than liquid desensitized explosives. 3 Denotes an impossible combination. 4 For pesticides only, where a material has the hazards of Class 3, Packing Group III, and Division 6.1, Packing Group III, the primary hazard is Division 6.1, Packing Group III.

Note 1: The most stringent packing group assigned to a hazard of the material takes precedence over other packing groups; for example, a material meeting Class 3 PG II and Division 6.1 PG I (oral toxicity) is classified as Class 3 PG I.

Note 2: A material which meets the definition of Class 8 and has an inhalation toxicity by dusts and mists which meets criteria for Packing Group I specified in § 173.133(a)(1) must be classed as Division 6.1 if the oral or dermal toxicity meets criteria for Packing Group I or II. If the oral or dermal toxicity meets criteria for Packing Group III or less, the material must be classed as Class 8.

(c) The following materials are not subject to the provisions of paragraph (a) of this section because of their unique properties:

- (1) A Class 1 (explosive) material that meets any other hazard class or division as defined in this part shall be assigned a division in Class 1. Class 1 materials shall be classed and approved in accordance with § 173.56 of this part;

- (2) A Division 5.2 (organic peroxide) material that meets the definition of any other hazard class or division as defined in this part, shall be classed as Division 5.2;

- (3) A Division 6.2 (infectious substance) material that also meets the definition of another hazard class or division, other than Class 7, or that also is a limited quantity Class 7 material, shall be classed as Division 6.2;

- (4) A material that meets the definition of a wetted explosive in § 173.124(a)(1) of this subchapter (Division 4.1). Wetted explosives are either specifically listed in the § 172.101 table or are approved by the Associate Administrator (see § 173.124(a)(1) of this subchapter); and

- (5) A limited quantity of a Class 7 (radioactive) material that meets the definition for more than one hazard class or division shall be classed in accordance with § 173.423.

[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]