FAQ on UN Cylinders and UN tubes

What cylinders and tubes can I use in Canada?

What are some differences between UN pressure receptacles and "TC" cylinders?

How do I identify a UN pressure receptacle?

Where can I get a UN pressure receptacle?

Design and Manufacture

What are the requirements for UN pressure receptacles?

Selection and Use

How do I select and use the right UN pressure receptacle for the dangerous goods?

What are the orientation requirements for UN pressure receptacles during transportation?

Periodic inspection and testing, and repair

What are the requirements for periodic inspection and testing of UN pressure receptacles?

Where can I find a periodic inspection and test body registered with Transport Canada?

How do I identify a UN pressure receptacle that has been periodically inspected and tested?

Facility Registration

How do I register to periodically inspect and test UN pressure receptacles in accordance with CSA B341?

How do I register to repair UN pressure receptacles in accordance with CSA B341?

How do I register with Transport Canada as a UN pressure receptacle manufacturer in accordance with CSA B341?

How do I register as an inspection body for the initial inspection and test of UN pressure receptacles in accordance with CSA B341?

How do I renew a Certificate of Registration?

How do I change the company name on a Certificate of Registration?

How can I request an amendment to an existing registration?

Where can I obtain more information?

What cylinders and tubes can I use in Canada?

Cylinders and tubes for transport of dangerous goods in Canada must be in accordance with the requirements set out in section 5.10 of the TDG Regulations. Specifically, subsection 5.10(1) references CSA B340 and CSA B342 which are two safety standards that address the requirements for cylinders and tubes used to transport Class 2 dangerous goods.

Clause 4.1.1.1 of CSA B340 specifies the selection and use requirements for cylinder and tube specifications that are authorised for use in Canada. This includes cylinders and tubes that have been in use in Canada for many years and that belong to one of the following groups of specifications:

  • Cylinders and tubes that have been manufactured in accordance with CSA B339. These cylinders and tubes are commonly referred to as “TC specification” cylinders and tubes because the prefix of the specification designation of these cylinders and tubes is marked as “TC”.
  • Cylinders and tubes that have been manufactured in accordance with the U.S. Department of Transportation’s Hazardous Materials Regulations entitled Title 49 of the Code of Federal Regulations of the United States (49 CFR). These cylinders and tubes are commonly referred to as “DOT specification” cylinders and tubes because the prefix of the specification designation of these cylinders and tubes is marked as “DOT”.
  • Cylinders and tubes that have been manufactured in accordance with Canadian regulations of the past. The prefix of the specification designation of these cylinders and tubes is marked as “CTC”, “CRC” or “BTC”.
  • Cylinders and tubes that have been manufactured in accordance with American regulations of the past. The prefix of the specification designation of these cylinders and tubes is marked as “ICC”.
  • Cylinders and tubes that were manufactured prior to 1 January 1993, in accordance with the conditions of a special permit issued under the Canadian Transport Commission (CTC) “Regulations for the Transportation of Dangerous Goods by Rail”. The marks that appear on these cylinders and tubes vary depending on the requirements specified in the respective CTC special permit.
  • Cylinders and tubes that were manufactured prior to 1 January 1993, in accordance with the conditions of an exemption issued under 49 CFR. The marks that appear on these cylinders and tubes vary depending on the requirements specified in the respective exemption, however, the prefix of the specification designation of these cylinders and tubes is marked as “ICC” or “DOT”.

It is important to note that Canada and the USA mutually recognize most of each other’s cylinder and tube specifications. The TC, CTC, CRC and BTC specification cylinders identified in the preceding list are authorised for use by 49 CFR. For more information on these cylinders and tubes, such as how to identify them, click here.

CSA B342 provides an alternative regulatory framework for using cylinders and tubes in Canada. This framework is closely aligned with the United Nations Recommendations on the Transport of Dangerous Goods – Model Regulations which has been developed to facilitate the international transport of dangerous goods. Cylinders and tubes used in accordance with CSA B342 are referred to as UN cylinders and UN tubes. Together, UN cylinders and UN tubes are referred to collectively as UN pressure receptacles. CSA B342 only authorises UN pressure receptacles that have been manufactured in accordance with CSA B341 and marked with the letters "CAN", depicting Canada as the country of approval or if they have been manufactured in accordance with 49 CFR and marked with the letters "USA" as the country of approval. Canada and the USA mutually recognize the regulatory approvals for UN pressure receptacles. This means that UN pressure receptacles marked with "CAN" or "USA" as the country of approval can be used seamlessly and interchangeably in the USA and Canada.

What are some differences between UN pressure receptacles and "TC" cylinders?

The requirements for UN pressure receptacles are based on standards published by the International Organization for Standardization (ISO). The filling requirements of UN pressure receptacles, as set out in CSA B342, are based on the UN Model Regulations and represent significant advances in harmonizing with the international community with regards to filling ratios for gases in cylinders. Consequently, the markings, the filling limits, and the requalification intervals are among the notable differences between UN pressure receptacles and "TC" cylinders. For most UN pressure receptacles, the requalification period is 10 years. For UN composite cylinders and other UN pressure receptacles used for toxic gases, the requalification period is 5 years. When referring to UN pressure receptacles, the term "periodic inspection and testing" is typically used instead of the term "requalification".

Clause 5.1.3 of CSA B342 and paragraph 171.12(a)(4) of 49 CFR recognize both UN cylinders with the "CAN" country of approval mark and UN cylinders with the "USA" country of approval mark. This makes it possible for UN cylinders that have either "CAN" or "USA" approval to be used interchangeably in both Canada and the USA.

How do I identify a UN pressure receptacle?

A UN pressure receptacle will have a permanent marking displayed on it that meets the marking requirements set out in clause 4.4 of CSA B341. Markings will be in a format similar to that shown below. The top row contains manufacturing marks such as the thread type, the country of manufacture, and the serial number assigned by the manufacturer. The middle row contains operational marks such as the test pressure, the tare or empty weight, and the minimum guaranteed wall thickness. The bottom row contains certification marks such as the UN packaging symbol, the ISO standard used for the design, manufacturing, and testing, and the country of approval. Please consult CSA B341 for more details on the marking requirements. Certain markings are not required for all UN pressure receptacle specifications, as denoted by 'where applicable'.

Schematic depicting how to identify markings on UN pressure receptacles
Text version of image

Arrangement of marks

The marks shall be placed in three groups, as follows:

  • (a) The manufacturing marks shall be the top grouping and appear in the sequence listed in Items (m) to (p).
  • (b) The operational marks in Items (f) to (j) shall be the middle grouping, and the test pressure (f) shall be immediately preceded by the working pressure (i) when the latter is marked.
  • (c) The certification marks shall be the bottom grouping and appear in the sequence listed in Items (a) to (e).

Certification marks (Bottom row)

  • (a) The UN packaging symbol
  • (b) The designation of the standard (e.g., ISO 9809-1) used for design, construction, and testing of the UN pressure receptacle. For acetylene cylinders, the designation of the standard applicable to the porous material (i.e., ISO 3807-1 or ISO 3807-2) shall be marked preceding the shell design standard designation and separated by a slash (e.g., "ISO 3807-2/ISO 9809-1").
  • (c) The mark of the country where the registration is granted. The letters "CAN" shall be marked on UN pressure receptacles whose designs have been registered with the Director.
  • (d) The identity mark or stamp of the inspection body that is registered with the Director.
  • (e) The date of the initial pressure test, i.e., the year (four digits) followed by the month (two digits),separated by a slash (/), e.g., "2006/12".

Operational marks (middle row)

  • (f) The test pressure in bar, preceded by the letters "PH" and followed by the letters "BAR".
  • (g) The mass of the empty UN pressure receptacle, including all permanently attached integral parts (e.g., neck ring and foot ring) in kilograms, followed by the letters "KG".
  • (h) The minimum guaranteed wall thickness of the UN pressure receptacle in millimetres, followed by the letters "MM".
  • (i) The working pressure in bar, preceded by the letters "PW". In the case of UN cryogenic receptacles, the maximum allowable working pressure, preceded by the letters "MAWP".
  • (j) In the case of UN pressure receptacles for liquefied gases and refrigerated liquefied gases, the water capacity in litres expressed to three significant digits rounded down to the last digit, followed by the letter "L". If the value of the minimum or nominal water capacity is an integer, the figures after the decimal point may be neglected.

Manufacturing marks (top row)

  • (m) Identification of the UN pressure receptacle thread using the code system specified in CGA TB-16 (e.g., 12N or 25E) or the complete thread designation (e.g., 3/4-14NGT or 25,8 ISO 10920 respectively).
  • (n) The manufacturer's registered mark. If Canada is not the country of manufacture, the manufacturer's mark shall be preceded by a character(s) identifying the country of manufacture, such as the distinguishing signs of motor vehicles in international traffic. The country mark and the manufacturer's mark shall be separated by a space or slash.
  • (o) The unique serial number assigned by the manufacturer.
  • (p) For steel UN pressure receptacles and composite UN pressure receptacles with a steel liner intended for the transport of gases with a risk of hydrogen embrittlement, the letter "H" to show compatibility of the steel (see ISO 11114-1).

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

Where can I get a UN pressure receptacle?

UN pressure receptacles may be purchased from manufacturers registered with Transport Canada pursuant to CSA B341 or manufacturers approved by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) accordance with 49 CFR. The Engineering Services Division at Transport Canada may be consulted via email at tdgcontainers-tmdcontenants@tc.gc.ca for information relating to facilities registered pursuant to CSA B341. PHMSA should be contacted for information on manufacturers approved in accordance with 49 CFR.

Design and Manufacture

What are the requirements for UN pressure receptacles?

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

How do I select and use the right UN pressure receptacle for the dangerous goods?

CSA B342 prescribes the selection requirements for UN pressure receptacles in relation to the gas to be contained, and prescribes other limits and requirements on the use of UN pressure receptacles in Canada. CSA B342 also prescribes the requirements for the design and testing of gas cylinder valves, valve protection, and pressure-relief devices.

It is the filler’s responsibility to select the appropriate UN pressure receptacle for dangerous goods. To facilitate selection, the consignor should become familiar with the components of the markings on UN pressure receptacles.

What are the orientation requirements for UN pressure receptacles during transportation?

Clause 4.7.1 of CSA B342 requires that all containers filled with refrigerated liquefied gas (e.g., UN1963 – helium, refrigerated liquid) or a liquefied flammable gas (e.g., UN1978 – propane) be transported in an upright position unless the container is designed for horizontal service. Clause 4.7.2 of CSA B342 requires that all containers be secured during transport to prevent shifting and overturning. Additional requirements apply to bundles of cylinders.

Periodic inspection and testing, and repair

What are the requirements for periodic inspection and testing of UN pressure receptacles?

For facilities located in Canada, only facilities registered by Transport Canada are allowed to periodically inspect and test or repair UN pressure receptacles authorized for use in Canada by CSA B342. Periodic inspection and testing of UN pressure receptacles must be conducted by a registered periodic inspection and test body in accordance with the requirements of clause 19 of CSA B341. Repairs of UN pressure receptacles must be conducted by a registered repair facility in accordance with Clause 20 of CSA B341. For periodic inspection and testing, the standard requires that additional procedures detailed in certain CGA publications and ISO standards be followed. A UN pressure receptacle must not be filled unless it is within its periodic inspection and testing period (interval) specified in CSA B342. The periodic inspection and testing frequency, which is specified in CSA B342, varies according to the type of UN pressure receptacle and its contents.

For facilities located outside of Canada, only facilities registered with Transport Canada or approved by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) are allowed to periodically inspect and test or repair UN pressure receptacles authorized for use in Canada by CSA B342. For facilities registered with Transport Canada, the periodic inspection and testing or repair of UN pressure receptacles must be conducted in accordance with the requirements of CSA B341. For facilities approved by PHMSA, the periodic inspection and testing or repair of UN pressure receptacles must be conducted 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).

Where can I find a periodic inspection and test body registered with Transport Canada?

The Engineering Services Division may be consulted via email at tdgcontainers-tmdcontenants@tc.gc.ca for a list of registered periodic inspection and test bodies registered with Transport Canada pursuant to CSA B341.

How do I identify 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 21 of CSA B341 specifies the marking requirements after periodic inspection and testing. The marking arrangement is as follows:

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:

BC
A
F
ED

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)

Facility Registration

How do I register to periodically inspect and test UN pressure receptacles in accordance with CSA B341?

To register to periodically inspect and test UN pressure receptacles, each facility must submit an application to the Director. Note that 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. The Certificate of Registration, once obtained, will show which standards the facility has been registered to.

To register to periodically inspect and test UN pressure receptacles by pressure test and visual inspection in accordance with CSA B341, a completed pressure test and visual inspection application form must be submitted. Applicants must satisfy the pressure testing training requirements that apply to periodic inspection and test personnel at registered facilities.

To register to periodically inspect and test UN pressure receptacles by ultrasonic examination and visual inspection in accordance with CSA B341, the information required by Annex B of CSA B341 must be submitted.

The Director will issue a Certificate of Registration to facilities meeting the requirements to periodically inspect and test UN pressure receptacles set out in Annex B of CSA B341. Upon registration, a registered mark is issued to each periodic inspection and test body. This mark must be permanently marked  on each UN pressure receptacle that is periodically inspected and tested by the registered facility. A Certificate of Registration is valid for a period of five years, prior to which time the inspection and test body must apply for renewal.

UN pressure receptacle manufacturers holding a Certificate of Registration are authorized to periodically inspect and test UN pressure receptacles of the specification listed on their Certificate of Registration.

How do I register to repair UN pressure receptacles in accordance with CSA B341?

To register to repair UN pressure receptacles, each facility must submit an application to the Director in accordance with Annex B of CSA B341. The Director will issue a Certificate of Registration to facilities meeting the requirements to repair UN pressure receptacles and MEGCs set out in Annex B of CSA B341. Upon registration, a registered mark is issued to each repair facility. This mark must be permanently marked on each UN pressure receptacle upon completion of the repair. A Certificate of Registration is valid for a period of five years, prior to which time the repair facility must apply for renewal.

UN pressure receptacle manufacturers holding a Certificate of Registration are authorized to repair UN pressure receptacles of the specification listed on their Certificate of Registration.

Applicants should consult the Engineering Services Division prior to submitting an application for registration. This consultation will be used to provide the applicant with feedback regarding the scope of the application and to confirm the type of information that will be needed to process the application. The goal of this consultation is to ensure that applicants are well informed prior to submitting the application and to ensure that the applicant is able to submit a complete application. Incomplete applications will significantly delay the review process and may result in the denial of the application. In order to initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a general description of the scope of registration that you are seeking.

How do I register with Transport Canada as a UN pressure receptacle manufacturer in accordance with CSA B341?

Any facility wishing to manufacture pressure receptacles in accordance with CSA B341 must be registered with Transport Canada. To register, each manufacturing facility must submit an application to the Director in accordance with Annex A of CSA B341. A UN pressure receptacle manufacturer registered with Transport Canada pursuant to CSA B341 will be authorized to display the letters "CAN" as the "country of approval" mark, the UN packaging symbol, and the other prescribed markings under CSA B341, only on pressure receptacle designs listed on the certificate of registration issued by Transport Canada. These requirements will apply regardless of where a UN pressure receptacle manufacturer is located, whether in Canada or abroad.

The Director will issue a Certificate of Registration to manufacturers of UN pressure receptacles who meet the requirements of the standard. The manufacturer's registered mark indicated on the Certificate of Registration is included in the permanent marking of each UN pressure receptacle. A Certificate of Registration is valid for a period of five years, prior to which time the manufacturing facility must apply for renewal.

Applicants should consult the Engineering Services Division prior to submitting an application for registration. This consultation will be used to provide the applicant with feedback regarding the scope of the application and to confirm the type of information that will be needed to process the application. The goal of this consultation is to ensure that applicants are well informed prior to submitting the application and to ensure that the applicant is able to submit a complete application. Incomplete applications will significantly delay the review process and may result in the denial of the application. In order to initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a general description of the scope of registration that you are seeking.

How do I register as an inspection body for the initial inspection and test of UN pressure receptacles in accordance with CSA B341?

To register to as an inspection body for the initial inspection and test of UN pressure receptacles, the applicant must submit an application to the Director in accordance with Annex A of CSA B341. The inspection body is responsible for the design type approval, pressure receptacle production testing and inspection, and certification to verify the conformity with the relevant ISO standard. The Director will issue a Certificate of Registration to applicants meeting the requirements set out in Annex A of CSA B341. Upon registration, a registered mark is issued to each inspection body. This mark is to be applied on each UN pressure receptacle at time of manufacture and shall be considered a declaration that the requirements for the UN pressure receptacle have been met. A Certificate of Registration is valid for a period of five years, prior to which time the facility must apply for renewal.

Applicants should consult the Engineering Services Division prior to submitting an application for registration. This consultation will be used to provide the applicant with feedback regarding the scope of the application and to confirm the type of information that will be needed to process the application. The goal of this consultation is to ensure that applicants are well informed prior to submitting the application and to ensure that the applicant is able to submit a complete application. Incomplete applications will significantly delay the review process and may result in the denial of the application. In order to initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a general description of the scope of registration that you are seeking.

How do I renew a Certificate of Registration?

Upon receipt of a renewal application, the Director may issue a new Certificate of Registration where the Director is satisfied that the applicant has demonstrated familiarity with the requirements of the standard and the capability to consistently meet the requirements of the standard. This Certificate of Registration will replace any Certificate of Registration previously issued to the facility.

Periodic Inspection and test bodies:

Periodic inspection and test bodies wishing to renew a Certificate of Registration authorising the periodic inspection and testing of UN pressure receptacles pursuant to CSA B341 must apply to the Director in the same manner as for an initial application. Facilities are expected to submit an application for renewal at least three months prior to the expiry date of the Certificate of Registration.

Repair facilities:

To renew a Certificate of Registration, the certificate holder must submit a written application for renewal in accordance with Clause B.2.5 of CSA B341, at least 3 months prior to expiry of the existing registration. The renewal application must indicate any changes to the information included in the initial application. If there are no changes, a statement to that effect should be made in the renewal application.

Manufacturers:

To renew a Certificate of Registration, the certificate holder must submit a written application for renewal in accordance with Clause A.2.2.7.1 of CSA B341, at least 3 months prior to expiry of the existing registration. The renewal application must indicate any changes to the information included in the initial application. If there are no changes, a statement to that effect should be made in the renewal application.

Inspection Bodies:

To renew a Certificate of Registration, the certificate holder must submit a written application for renewal in accordance with Clause A.4.4 of CSA B341, at least 3 months prior to expiry of the existing registration. The renewal application must indicate any changes to the information included in the initial application. If there are no changes, a statement to that effect should be made in the renewal application.

How do I change the company name on a Certificate of Registration?

A Certificate of Registration is issued to a legal entity who is the certificate holder. A certificate of registration may not be conveyed from one certificate holder to another. A name change on a Certificate of Registration is only permitted if the certificate holder remains the same legal entity as before. In such a case the certificate holder may submit a written request to the Director. The request must include the Certificate of Registration number, the new certificate holder name, a justification that the conditions for name change apply, and the date on which the change is proposed to become effective.

How can I request an amendment to an existing registration?

A facility registered with Transport Canada pursuant to CSA B341 must submit an application for an amendment to a Certificate of Registration to the Director when there is a change to the information previously submitted to the Director for the purpose of obtaining a Certificate of Registration or when the facility wishes to request a change in the scope of its existing registration.

The Director may issue a revised Certificate of Registration where the Director is satisfied that the applicant has demonstrated familiarity with the requirements of the standard and the capability to consistently meet the requirements of the standard depending on the nature of the amendment. This Certificate of Registration will replace any Certificate of Registration previously issued to the facility.

Periodic inspection and test bodies:

Periodic inspection and test bodies wishing to amend an existing Certificate of Registration authorising the periodic inspection and test of UN pressure receptacle pursuant to CSA B341 must apply to the Director in the same manner as for an initial application.

Repair facilities:

The information required to request an amendment to an existing registration will vary depending on the nature of the amendment. Applicants should consult the Engineering Services Division in order to seek further instructions. To initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a reference to your file number as well as a general description of the amendment that you are seeking.

Manufacturers:

The information required to request an amendment to an existing registration will vary depending on the nature of the amendment. Applicants should consult the Engineering Services Division in order to seek further instructions. To initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a reference to your file number as well as a general description of the amendment that you are seeking.

Inspection bodies:

The information required to request an amendment to an existing registration will vary depending on the nature of the amendment. Applicants should consult the Engineering Services Division in order to seek further instructions. To initiate a consultation, please submit a request for a consultation via email to tdgcontainers-tmdcontenants@tc.gc.ca and include a reference to your file number as well as a general description of the amendment that you are seeking.

Where can I obtain more information?

For more information:

Inquiries pertaining to applications for registration:
1-855-298-1520
After choosing the language (1 for English, 2 for French), press option 1.

MOCregister-Registrecontenant@tc.gc.ca

Technical inquiries pertaining to UN pressure receptacles:
tdgcontainers-tmdcontenants@tc.gc.ca.
Please include the text "Cylinders" in the subject line.

Quick links

CSA B341

Information on CSA B341 (the standard on "UN pressure receptacles and multiple-element gas containers for the transport of dangerous goods").

CSA B342

Information on CSA B342 (the standard on "Selection and use of UN pressure receptacles and multiple-element gas containers for the transport of dangerous goods, Class 2").

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