政策法规现行有效美国危险品合规

§ 173.40 General packaging requirements for toxic materials packaged in cylinders.

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

该条款规定了美国境内运输毒性气体（2.3类）和毒性物质（6.1类）中危险区A级和B级材料的气瓶包装通用要求。核心内容包括：禁止使用乙炔气瓶、非重复充装气瓶及UN管/MEGCs（针对A级）；对特定铝合金气瓶及复合材料气瓶的使用限制；严格的压力与预留空间（outage）计算标准（55°C下不得超压或液满）；阀门必须为无填料型或带密封盖的填料型，且需通过跌落测试保护；以及禁止气瓶互联（MEGCs除外）。违反这些物理包装规范将导致货物被拒运或面临高额罚款。

When this section is referenced for a Hazard Zone A or B hazardous material elsewhere in this subchapter, the requirements in this section are applicable to cylinders used for that material.

(a) Authorized cylinders. (1) A cylinder must conform to a DOT specification or UN standard prescribed in subpart C of part 178 of this subchapter, or a TC, CTC, CRC, or BTC cylinder authorized in § 171.12 of this subchapter, except that acetylene cylinders and non-refillable cylinders are not authorized. The use of UN tubes and MEGCs is prohibited for Hazard Zone A materials.

- (2) The use of a specification 3AL cylinder made of aluminum alloy 6351-T6 is prohibited for a Division 2.3 Hazard Zone A material or a Division 6.1 Hazard Zone A material.

- (3) A UN composite cylinder certified to ISO-11119-3 is not authorized for a Division 2.3 Hazard Zone A or B material.

- (4) For UN seamless cylinders used for Hazard Zone A materials, the maximum water capacity is 85 L.

(b) Outage and pressure requirements. For DOT specification cylinders, the pressure at 55 °C (131 °F) of Hazard Zone A and Hazard Zone B materials may not exceed the service pressure of the cylinder. Sufficient outage must be provided so that the cylinder will not be liquid full at 55 °C (131 °F).
(c) Closures. Each cylinder containing a Hazard Zone A material must be closed with a plug or valve conforming to the following:

- (1) Each plug or valve must have a taper-threaded connection directly to the cylinder and be capable of withstanding the test pressure of the cylinder without damage or leakage. For UN pressure receptacles, each valve must be capable of withstanding the test pressure of the pressure receptacle and be connected directly to the pressure receptacle by either a taper thread or other means which meets the requirements of ISO 10692-2: (IBR, see § 171.7 of this subchapter).

- (2) Each valve must be of the packless type with non-perforated diaphragm, except that, for corrosive materials, a valve may be of the packed type with an assembly made gas-tight by means of a seal cap with gasketed joint attached to the valve body or the cylinder to prevent loss of material through or past the packing.

- (3) Each valve outlet must be sealed by a threaded cap or threaded solid plug and inert gasketing material.

- (4) The materials of construction for the cylinder, valves, plugs, outlet caps, luting, and gaskets must be compatible with each other and with the lading.

(d) Additional handling protection. Each cylinder or cylinder overpack combination offered for transportation containing a Division 2.3 or 6.1 Hazard Zone A or B material must conform to the valve damage protection performance requirements of this section. In addition to the requirements of this section, overpacks must conform to the overpack provisions of § 173.25.

- (1) DOT specification cylinders must conform to the following:

(i) Each cylinder with a wall thickness at any point of less than 2.03 mm (0.08 inch) and each cylinder that does not have fitted valve protection must be overpacked in a box. The box must conform to overpack provisions in § 173.25. Box and valve protection must be of sufficient strength to protect all parts of the cylinder and valve, if any, from deformation and breakage resulting from a drop of 2.0 m (7 ft) or more onto a non-yielding surface, such as concrete or steel, impacting at an orientation most likely to cause damage. “Deformation”means a cylinder or valve that is bent, distorted, mangled, misshapen, twisted, warped, or in a similar condition.

- (ii) Each cylinder with a valve must be equipped with a protective metal or plastic cap, other valve protection device, or an overpack which is sufficient to protect the valve from breakage or leakage resulting from a drop of 2.0 m (7 ft) onto a non-yielding surface, such as concrete or steel. Impact must be at an orientation most likely to cause damage.

- (2) Each UN cylinder containing a Hazard Zone A or Hazard Zone B material must have a minimum test pressure in accordance with P200 of the UN Recommendations (IBR, see § 171.7 of this subchapter). For Hazard Zone A gases, the cylinder must have a minimum wall thickness of 3.5 mm if made of aluminum alloy or 2 mm if made of steel or, alternatively, cylinders may be packed in a rigid outer packaging that meets the Packing Group I performance level when tested as prepared for transport, and that is designed and constructed to protect the cylinder and valve from puncture or damage that may result in release of the gas.

(e) Interconnection. Cylinders may not be manifolded or connected. This provision does not apply to MEGCs containing Hazard Zone B materials in accordance with § 173.312.

[67 FR 51642, Aug. 8, 2002, as amended at 67 FR 61289, Sept. 30, 2002; 68 FR 24660, May 8, 2003; 71 FR 33880, June 12, 2006; 76 FR 3371, Jan. 19, 2011; 81 FR 3672, Jan. 21, 2016; 82 FR 15876, Mar. 30, 2017]