UN cylinders, tubes, cryogenic receptacles and MEGCs (up to 3000 L) for transporting Class 2 dangerous goods (gases).
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Standards
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, multiple-element gas containers, and other pressure receptacles for the transport of dangerous goods, Class 2”).
Requirements
Find information on the requirements for UN cylinders and tubes, 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.
Registered facilities
Search the TDG facilities database to find information on the following facilities registered with Transport Canada:
- UN pressure receptacle manufacturers
- UN pressure receptacle periodic inspection and test facilities (requalifiers)
- inspection bodies for manufacture of UN pressure receptacles
- design review agencies for multiple-element gas containers (MEGC)
Transporting Class 2 gases
CSA B341 and CSA B342 standards set out domestic requirements for the transport of Class 2 dangerous goods (gases) using UN cylinders, tubes, and multiple-element gas containers (MEGCs). Aligned with UN Model Regulations and ISO standards, they reflect advancements in safety, technology, and industry practices. MEGCs are high-pressure assemblies of interconnected gas containers within a frame, designed for multi-modal transport. Transport Canada actively contributes to the development of these international standards through participation in ISO technical committees.
Differences between UN pressure receptacles and “TC” cylinders are the markings, the filling limits, and the requalification intervals are among the notable differences. The following is an example of markings applied to a UN cylinder:
Text description
The top row contains manufacturing marks such as the cylinder 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.
The filling requirements of UN pressure receptacles, as set out in CSA B342, are based on those prescribed in Packing Instruction P200 of the UN Model Regulations and represent significant advances in harmonizing filling ratios for gases in 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.
UN cylinders bearing the “CAN” country approval mark are accepted in the United States on the same basis as those marked “USA”.This reciprocity allows users of either “CAN” or “USA” marked UN cylinders to benefit from seamless cross-border use and regulatory alignment not available under previous regulations.