UN cylinders, UN tubes, UN cryogenic receptacles, and multiple-element gas containers (MEGCs) – Requirements

Information on the requirements for UN cylinders, UN tubes, UN cryogenic receptacles and multiple-element gas containers (MEGCs) including registration for manufacturers, inspection bodies, and periodic inspection and test bodies, as well as guidance on selecting and using these containers for transporting Class 2 dangerous goods.

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General

Cylinders and tubes that can be used in Canada

In Canada, cylinders and tubes used for transporting dangerous goods must comply with section 5.10 of the TDG Regulations, referencing CSA B340 and CSA B342 for safety standards. These standards outline requirements for cylinders and tubes used to transport Class 2 (Gases) dangerous goods.

CSA B342 sets out the requirements for selecting and using UN cylinders and tubes in Canada. These are collectively called UN pressure receptacles, and Clause 4.1.7 lists which ones are authorized.

CSA B340 (Clause 4.1.1.1) specifies the requirements for selecting and using cylinder and tube specifications that are authorized for use in Canada, including TC cylinders. These cylinders and tubes fall into the following groups of specifications:

  • TC cylinders and tubes – manufactured according to CSA B339 (marked “TC”)
  • Department of Transportation (DOT) cylinders and tubes – manufactured according to U.S. rules in 49 CFR (marked “DOT”)
  • older Canadian specifications – marked CTC, CRC, or BTC
  • older U.S. specifications – marked ICC
  • special permits – Canadian Transport Commission (CTC) – manufactured before 1 January 1993 under CTC permits (markings vary)
  • exemptions (U.S.) – made before 1 January 1993 under 49 CFR exemptions (marked “ICC” or “DOT”)

Canada and the U.S. recognize each other’s approved UN pressure receptacles, allowing those marked "CAN" or "USA" to be used interchangeably in both countries (under Clause 5.1.3 of CSA B342 and paragraph 171.12(a)(4) of the U.S. Department of Transportation’s Hazardous Materials Regulations in Title 49 of the U.S. Code of Federal Regulations).

Differences between UN pressure receptacles and "TC" cylinders

The requirements for UN pressure receptacles are based on standards from the International Organization for Standardization (ISO). Key differences between UN pressure receptacles and "TC" cylinders include marks, filling limits, and requalification intervals. For most UN pressure receptacles, the requalification period is 10 years, but for composite UN pressure receptacles and those used for toxic gases, it is 5 years. Instead of "requalification," the term "periodic inspection and testing" is used.

Identifying a UN pressure receptacle

A UN pressure receptacle will have permanent marks that follow the requirements in CSA B341. The marks will look like the example below. The top row shows manufacturing marks, like the thread type, country of manufacture, and serial number. The middle row has operational marks like test pressure, empty weight, and minimum wall thickness. The bottom row shows certification marks, such as the UN packaging symbol, the ISO standard used, and the country of approval. Please consult Clause 4.4 of CSA B341 for more details on the marking requirements. Some marks may not be required for all types of UN pressure receptacles, as noted by "where applicable."

Text version

The image has three lines of information, each read from left to right.

The first line:

25E: Identification of thread type, where applicable

F/MXXXX: Manufacturer’s registered mark, preceded by the mark of the country of manufacture

765432: Serial number assigned by the manufacturer

H: The letter “H” to show compatibility of the steel, where applicable

The second line:

PW200: Working pressure in bar, where applicable

PH300BAR: Test pressure in bar

62.1 KG: Mass when empty, in KG

50 L: Water capacity in L, for liquefied gases

5.8 MM: Minimum guaranteed wall thickness, in mm

The third line:

UN: UN packaging symbol

ISO 9809-1: The standard (e.g., ISO 9809-1) used for design, construction, and testing

CAN: Mark of the country where registration is granted, UN pressure receptacles marked “CAN” or “USA” are authorize for transport in Canada and the USA

IB: The identity mark or stamp of the inspection body that is registered with the Director

2006/12: The date of the initial pressure test, year followed by month separated by a slash

Additional possible marks include:

  • other marks relating to the mass of the empty cylinder for cylinders used to transport acetylene
  • the letters "UW" indicating suitability for underwater use, where applicable

Obtaining a UN pressure receptacle

UN pressure receptacles may be purchased from manufacturers registered with Transport Canada pursuant to CSA B341 or from those approved by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) accordance with 49 CFR.

Search the TDG database for manufacturers of UN pressure receptables registered with Transport Canada.

For information on manufacturers approved under 49 CFR, please contact PHMSA directly.

Design and manufacture

UN pressure receptacles for use in Canada must be designed, manufactured, initially inspected and initially tested in conformance with the requirements set out in CSA B341 when marked with the letters "CAN" as the country of approval or 49 CFR when marked with the letters "USA" as the country of approval. The requirements specified in CSA B341 and 49 CFR pertain to design, manufacturing and testing, inspection and marking.

Selection and use

CSA B342 outlines the requirements for selecting UN pressure receptacles based on the gas they will hold, as well as other limits and conditions for using them in Canada. It also covers the requirements for the design and testing of gas cylinder valves, valve protection, and pressure-relief devices. The person filling the cylinder is responsible for choosing the correct UN pressure receptacle for the dangerous goods.

Orientation requirements for UN pressure receptacles during transportation

According to Clause 4.7 of CSA B342, containers filled with refrigerated liquefied gases (like UN1963 – helium, refrigerated liquid) or liquefied flammable gases (like UN1978 – propane) must be transported upright, unless the container is designed for horizontal service. All containers must also be secured during transport to prevent shifting and overturning.

Requirements for periodic inspection and testing

For facilities located in Canada, only facilities registered with Transport Canada are allowed to periodically inspect and test, or repair UN pressure receptacles approved for use by CSA B342. Periodic inspection and testing must be done by a registered facility in accordance with Clause 20 of CSA B341, and repairs must be made by a registered repair facility in accordance with Clause 21 of CSA B341. The periodic inspection and testing procedures must also follow specific CGA publications and ISO standards that are referenced in CSA B341. A UN pressure receptacle must not be filled unless it is within its periodic inspection and testing period, which varies depending on the type of UN pressure receptacle and its contents.

For facilities located outside of Canada, only those registered with Transport Canada or approved by the U.S. Department of Transportation’s PHMSA under the 49 CFR can periodically inspect and test, or repair UN pressure receptacles approved for use in Canada. If the facility is registered with Transport Canada, it must follow CSA B341. If it is approved by PHMSA, it must follow the 49 CFR.

Search the TDG database for UN pressure receptacle periodic inspection and test bodies registered with Transport Canada.

Identifying a UN pressure receptacle that has been periodically inspected and tested

A periodic inspection and test body registered with Transport Canada must mark the UN pressure receptacle in accordance with CSA B341. Clause 22 of CSA B341 specifies the marking requirements after periodic inspection and testing.

A B C

A = the letters "CAN" if Canada is not the country of approval for manufacture
B = the registered mark of the periodic inspection and test body
C = the date of the periodic inspection and test, i.e., the year (two digits) followed by the month (two digits), separated by a slash. Four digits may be used to indicate the year

Example: CAN 123 2016/01 is an example of the markings applied to a UN refillable pressure receptacle that has passed a periodic inspection and test.

A facility approved by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) must mark UN pressure receptacles in accordance with the U.S. Department of Transportation’s Hazardous Materials Regulations entitled Title 49 of the U.S. Code of Federal Regulations (49 CFR). The marking arrangement is as follows:

A = month requalification performed (one digit)

B = first character of the facility’s requalification identification number (RIN) issued by PHMSA

C = second character of the facility’s requalification identification number (RIN) issued by PHMSA

D = third character of the facility’s requalification identification number (RIN) issued by PHMSA

E = fourth character of the facility’s requalification identification number (RIN) issued by PHMSA

F = year requalification performed (last two digits)

Registration

Registering as:

  • UN pressure receptacle manufacturer
  • inspection body for the inspection and test of UN pressure receptacles during design qualification and manufacturing process
  • periodic inspection and test body and repair facility (pressure testing training required)
  • design review agency

To register, the applicant must submit a completed application form. The Certificate of Registration is valid for five years, after which the facility must apply for renewal.

A registration to requalify cylinders pursuant to CSA B339 does not automatically allow a facility to periodically inspect and test UN pressure receptacles; registration to CSA B341 is required.

Amending, renewing or cancelling my registration

A registration can be amended, renewed or cancelled by completing the application form.

Certificate of Registration and mark

When approved, applicants receive a Certificate of Registration that includes their registered mark and a list of their authorized activities:

  • manufacturers – authorized to manufacture specific UN pressure receptacle designs. Only manufacturers registered with Transport Canada may display “CAN” as the country approval mark
  • inspection bodies – authorized to inspect specific UN pressure receptacle designs during qualification and manufacture. Their registered mark must be applied to each receptacle at the time of manufacture
  • periodic inspection, test, and repair facilities – authorized to carry out periodic inspection, testing, or repair of specific UN pressure receptacle specifications
  • design review agency – authorized to approve the designs for MEGCs. Their registered mark must be applied to each MEGC at the time of manufacture

Contact us

Inquiries pertaining to applications for registration

Telephone: 1-855-298-1520
After choosing the language (1 for English, 2 for French), press option 1.

Email: MOCregister-Registrecontenant@tc.gc.ca

Technical inquiries

Email: tdgcontainers-tmdcontenants@tc.gc.ca
Please include the text "Cylinders" in the subject line.

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