49 CFR 171.12: Hazardous materials shipments with Canada and Mexico

Last reviewed: October 14, 2026

This section covers hazardous materials shipped between the United States and Canada or Mexico. It lets certain shipments by motor carrier and rail follow the Transport Canada TDG Regulations, with conditions on packaging, cylinders and tanks. Shipments to or from Mexico must meet this subchapter, with added rules for materials poisonous by inhalation.

Applies toHazardous materials transported between Canada and the United States, in transit through the United States, or between the United States and Mexico.

What it says

  1. A hazardous material moving between Canada and the United States, or transiting the United States, may travel by motor carrier and rail under the Transport Canada TDG Regulations if the requirements of §§ 171.22 and 171.23, as applicable, and this section are met.

    49 CFR 171.12(a)(1)“may be offered for transportation or transported by motor carrier and rail in accordance with the Transport Canada TDG Regulations”
  2. Except as otherwise provided in this subpart and subpart C of this part, parts 172, 173, and 178 of this subchapter do not apply to a material transported under the Transport Canada TDG Regulations.

    49 CFR 171.12(a)(1)“the requirements in parts 172, 173, and 178 of this subchapter do not apply for a material transported in accordance with the Transport Canada TDG Regulations”
  3. Where this subchapter requires a DOT specification or UN standard packaging, a packaging authorized by the Transport Canada TDG Regulations may be used only if it is equivalent to the corresponding DOT specification or UN packaging, subject to the limitations of this part.

    49 CFR 171.12(a)(2)“a packaging authorized by the Transport Canada TDG Regulations may be used, subject to the limitations of this part, and only if it is equivalent”
  4. A rail tank car used as a bulk packaging under the Transport Canada TDG Regulations, as described in paragraph (a)(3), must conform to the requirements of Containers for Transport of Dangerous Goods by Rail.

    49 CFR 171.12(a)(3)(v)“Rail tank cars must conform to the requirements of Containers for Transport of Dangerous Goods by Rail”
  5. When transporting Class 1 (explosive) material, rail and motor carriers must comply with 49 CFR 1572.9 and 1572.11 to the extent the requirements apply.

    49 CFR 171.12(a)(5)“rail and motor carriers must comply with 49 CFR 1572.9 and 1572.11 to the extent the requirements apply”
  6. Lithium metal cells and batteries (UN3090) and lithium ion cells and batteries (UN3480) are forbidden for transport as cargo aboard passenger-carrying aircraft.

    49 CFR 171.12(a)(6)“are forbidden for transport as cargo aboard passenger-carrying aircraft”
  7. Unless otherwise excepted, hazardous materials shipments between Mexico and the United States must conform to all applicable requirements of this subchapter.

    49 CFR 171.12(b)“Unless otherwise excepted, hazardous materials shipments from Mexico to the United States or from the United States to Mexico must conform to all applicable requirements of this subchapter.”
  8. For a material poisonous by inhalation moving by highway or rail between Mexico and the United States, the package must be marked in accordance with § 172.313 of this subchapter.

    49 CFR 171.12(b)(3)“The package must be marked in accordance with § 172.313 of this subchapter.”

Common questions

Can I ship hazardous materials between the U.S. and Canada under the Canadian TDG Regulations?

Yes, by motor carrier and rail, if the requirements in §§ 171.22 and 171.23, as applicable, and this section are met.

“may be offered for transportation or transported by motor carrier and rail in accordance with the Transport Canada TDG Regulations”

Do U.S. rules apply to hazardous materials shipments to or from Mexico?

Yes. Unless otherwise excepted, these shipments must conform to all applicable requirements of this subchapter.

“Unless otherwise excepted, hazardous materials shipments from Mexico to the United States or from the United States to Mexico must conform to all applicable requirements of this subchapter.”

Can lithium batteries go as cargo on passenger aircraft under this section?

No. Lithium metal cells and batteries (UN3090) and lithium ion cells and batteries (UN3480) are forbidden as cargo aboard passenger-carrying aircraft.

“are forbidden for transport as cargo aboard passenger-carrying aircraft”

The text of 49 CFR 171.12

Electronic Code of Federal Regulations (eCFR), current as of March 31, 2026 · Read it on eCFR

North American Shipments

(a) Requirements for the use of the Transport Canada TDG Regulations—(1) Applicability. A hazardous material transported from Canada to the United States, from the United States to Canada, or transiting the United States to Canada or a foreign destination may be offered for transportation or transported by motor carrier and rail in accordance with the Transport Canada TDG Regulations (IBR, see § 171.7), an equivalency certificate (permit for equivalent level of safety), or a temporary certificate (permit in support of public interest) issued by Transport Canada as an alternative to the TDG Regulations, as authorized in § 171.22, provided the requirements in §§ 171.22 and 171.23, as applicable, and this section are met. In addition, a cylinder, pressure drum, MEGC, cargo tank motor vehicle, portable tank or rail tank car authorized by the Transport Canada TDG Regulations may be used for transportation to, from, or within the United States provided the cylinder, pressure drum, MEGC, cargo tank motor vehicle, portable tank, or rail tank car conforms to the applicable requirements of this section. Except as otherwise provided in this subpart and subpart C of this part, the requirements in parts 172, 173, and 178 of this subchapter do not apply for a material transported in accordance with the Transport Canada TDG Regulations.

(2) General packaging requirements. When the provisions of this subchapter require a DOT specification or UN standard packaging to be used for transporting a hazardous material, a packaging authorized by the Transport Canada TDG Regulations may be used, subject to the limitations of this part, and only if it is equivalent to the corresponding DOT specification or UN packaging (see § 173.24(d)(2) of this subchapter) authorized by this subchapter.

(3) Bulk packagings. A portable tank, cargo tank motor vehicle or rail tank car equivalent to a corresponding DOT specification and conforming to and authorized by the Transport Canada TDG Regulations may be used provided—

(i) An equivalent type of packaging is authorized for the hazardous material according to the § 172.101 table of this subchapter;

(ii) The portable tank, cargo tank motor vehicle or rail tank car conforms to the requirements of the applicable part 173 bulk packaging section specified in the § 172.101 table for the material to be transported;

(iii) The portable tank, cargo tank motor vehicle or rail tank car conforms to the requirements of all assigned bulk packaging special provisions (B codes, and T and TP codes) in § 172.102 of this subchapter; and

(iv) The bulk packaging conforms to all applicable requirements of §§ 173.31, 173.32, 173.33 and 173.35 of this subchapter, and parts 177 and 180 of this subchapter. The periodic retests and inspections required by §§ 173.31, 173.32 and 173.33 of this subchapter may be performed in accordance with part 180 of this subchapter or in accordance with the requirements of the TDG Regulations provided that the intervals prescribed in part 180 of this subchapter are met.

(v) Rail tank cars must conform to the requirements of Containers for Transport of Dangerous Goods by Rail (IBR, see § 171.7).

(4) Cylinders, Pressure Drums, and MEGCs. When the provisions of this subchapter require that a DOT specification or a UN pressure receptacle must be used for a hazardous material, a packaging authorized by the Transport Canada TDG Regulations may be used only if it corresponds to the DOT specification or UN standard authorized by this subchapter. Unless otherwise excepted in this subchapter, a cylinder (including a UN pressure receptacle) or MEGC may not be transported unless—

(i) The packaging is a UN pressure receptacle or MEGC marked with the letters “CAN” for Canada as a country of manufacture or a country of approval or is a cylinder that was manufactured, inspected and tested in accordance with a DOT specification or a UN standard prescribed in part 178 of this subchapter, except that cylinders (including UN pressure receptacles) not conforming to these requirements must meet the requirements in § 171.23. Each cylinder (including UN pressure receptacles) must conform to the applicable requirements in part 173 of this subchapter for the hazardous material involved.

(ii) A Canadian Railway Commission (CRC), Board of Transport Commissioners for Canada (BTC), Canadian Transport Commission (CTC) or Transport Canada (TC) specification cylinder manufactured, originally marked, and approved in accordance with the TDG Regulations, and in full conformance with the TDG Regulations is authorized for transportation to, from or within the United States provided:

(A) The CRC, BTC, CTC or TC specification cylinder corresponds with a DOT specification cylinder and the markings are the same as those specified in this subchapter, except that the original markings were “CRC”, “BTC”, “CTC”, or “TC”;

(B) The cylinder has been requalified under a program authorized by the TDG Regulations or subpart I of part 107 of this chapter;

(C) When the regulations authorize a cylinder for a specific hazardous material with a specification marking prefix of “DOT,” a cylinder marked “CRC”, “BTC”, “CTC”, or “TC” otherwise bearing the same markings required of the specified “DOT” cylinder may be used; and

(D) Transport of the cylinder and the material it contains is in all other respects in conformance with the requirements of this subchapter (e.g. valve protection, filling requirements, operational requirements, etc.).

(iii) Authorized CRC, BTC, CTC, or TC specification cylinders that correspond with a DOT specification cylinder are as follows:

Table 1 to Paragraph (a)(4)(iii): Corresponding Specification Cylinders TC DOT

(some or all of these specifications may instead be marked with the prefix ICC) CTC

(some or all of these specifications may instead be marked with the prefix BTC or CRC) TC-3AM DOT-3A [ICC-3] CTC-3A TC-3AAM DOT-3AA CTC-3AA TC-3ANM DOT-3BN CTC-3BN TC-3EM DOT-3E CTC-3E TC-3HTM DOT-3HT CTC-3HT TC-3ALM DOT-3AL CTC-3AL DOT-3B CTC-3B TC-3AXM DOT-3AX CTC-3AX TC-3AAXM DOT-3AAX CTC-3AAX DOT-3A480X CTC-3A480X TC-3TM DOT-3T TC-4AAM33 DOT-4AA480 CTC-4AA480 TC-4BM DOT-4B CTC-4B TC-4BM17ET DOT-4B240ET CTC-4B240ET TC-4BAM DOT-4BA CTC-4BA TC-4BWM DOT-4BW CTC-4BW TC-4DM DOT-4D CTC-4D TC-4DAM DOT-4DA CTC-4DA TC-4DSM DOT-4DS CTC-4DS TC-4EM DOT-4E CTC-4E TC-39M DOT-39 CTC-39 TC-4LM DOT-4L CTC-4L TC-8WM DOT-8 CTC-8 TC-8WAM DOT-8AL CTC-8AL

(5) Class 1 (explosive) materials. When transporting Class 1 (explosive) material, rail and motor carriers must comply with 49 CFR 1572.9 and 1572.11 to the extent the requirements apply.

(6) Lithium cells and batteries. Lithium metal cells and batteries (UN3090) and lithium ion cells and batteries (UN3480) are forbidden for transport as cargo aboard passenger-carrying aircraft. The outside of each package or overpack that contains lithium cells or batteries meeting the conditions for exception in § 173.185(c) of this subchapter and transported in accordance with the Transport Canada TDG Regulations must be marked or labeled in accordance with § 173.185(c)(1)(iii), (iv), and (vi), as appropriate.

(b) Shipments to or from Mexico. Unless otherwise excepted, hazardous materials shipments from Mexico to the United States or from the United States to Mexico must conform to all applicable requirements of this subchapter. When a hazardous material that is a material poisonous by inhalation (see § 171.8) is transported by highway or rail from Mexico to the United States, or from the United States to Mexico, the following requirements apply:

(1) The shipping description must include the words “Toxic Inhalation Hazard” or “Poison-Inhalation Hazard” or “Inhalation Hazard”, as required in § 172.203(m) of this subchapter.

(2) The material must be packaged in accordance with requirements of this subchapter.

(3) The package must be marked in accordance with § 172.313 of this subchapter.

(4) Except as provided in paragraph (b)(5) of this section, the package must be labeled or placarded POISON GAS or POISON INHALATION HAZARD, as appropriate, in accordance with subparts E and F to part 172 of this subchapter.

(5) A label or placard that conforms to the UN Recommendations (IBR, see § 171.7) specifications for a “Division 2.3” or “Division 6.1” label or placard may be substituted for the POISON GAS or POISON INHALATION HAZARD label or placard required by §§ 172.400(a) and 172.504(e) of this subchapter on a package transported in a closed transport vehicle or freight container. The transport vehicle or freight container must be marked with identification numbers for the material, regardless of the total quantity contained in the transport vehicle or freight container, in the manner specified in § 172.313(c) of this subchapter and placarded as required by subpart F of this subchapter.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of March 31, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.