CSA Cylinder Standards – June 2018 Update

compressed gas cylinders

CSA issues new Editions of TDG Class 2 Cylinder Standards

Transport Canada has issued an update “Notice” to inform the regulated community of recent updates to the Canadian Standards Association (CSA) standards addressing the requirements for the manufacture/qualification, selection and use of cylinders used in the transportation of dangerous goods (TDG).

Although these standards are primarily for compressed gases, their use may also be required or permitted for DG substances, other than Class 2, that may produce toxic or flammable vapours. Typically, this information is cited in standard TP14850 by reference in the packing instructions.

The four standards involved are:

CSA B339, CSA B340
(design/manufacture/qualification and selection/use, respectively) regarding cylinders, spheres and tubes, and other similar containers.
CSA B341, CSA B342
(manufacture/qualification and selection/use, respectively) regarding UN pressure receptacles and multi-element gas containers (MEGC).

Why Two Sets? Origins

The B339/B340 set are the seventh revision to the standards based on the older CTC (Canadian Transport Commission, pre-Transport Canada) national standards for these types of containers. These versions are the seventh revision of the original editions commencing in 1983 and 1986 respectively.

This contrasts with the B341/B342 set derived from the standards in UN Recommendation model regulations. The Canadian versions referenced here are the 3rd editions following 2009 and 2015 editions. Issuing these as CSA standards, rather than just adopting the UN Recommendations, facilitates incorporating the country-specific aspects such as special permits, reciprocity, etc.


Although the 2 sets of standards are similar the “Definition” section of the primary title in each set provides some clarification:

Type/Standard CSA B339/B340 CSA B341/B342 “UN”
Cylinder ≤ 450 L, >275 kPa absolute ≤ 150 L
Sphere ≤ 45.4 L, >275 kPa absolute Not categorically defined
Tube > 450 L, >12.4 MPa 150 – 3000 L
Cryogenic Receptical Not categorically defined ≤ 1000 L

In addition, the UN series includes reference to “metal hydride storage systems” as a specific type of pressure receptacle (UN3468).

More Harmony

In keeping with the general expansion of harmonization in recent years, these updates expand the use of cylinders re-qualified in a country other than where they were manufactured; and increase the reciprocity for receipt of US authorized cylinders. Provision is also made in CSA B340 for conditional use of non-specification vacuum-insulated helium refrigerated liquid closed containers.

Protocol Changes

CSA 341/342 also adds three additional references, in keeping with the 19th Edition of the UN Recommendations, to ISO standards- ISO 3807:2013, ISO 10247:2014 and ISO 11515:2013.

CSA 339 revises or clarifies test protocols for certain specified cylinder types and changes the carbon fibre requirements used in TC-3CCM cylinders.


As introduced in the 2017 expansion of “as amended” standards, the 2018 editions become mandatory six months after publication- but may be used immediately.

Additional details may be found on Transport Canada’s website.

The site also has a link to registering for “view only” access to the CSA standards.

Clifton J. Brown

Clifton J. Brown

Clifton Brown has over 35 years of practical experience in the Canadian chemical and manufacturing industries. He has worked in research, quality, environment, health and safety in a range of industries including explosives, pesticides, manufacturing/contract packaging, pharmaceuticals, and specialty chemicals. This experience has provided a basis for dealing with a variety of regulatory approaches that have been useful in implementing and evaluating/auditing compliance. This experience has also been useful in effectively helping others to understand and apply the regulations in a North American context. Clifton represents ICC on the RDC regulatory and safe operations committees, participates in Transport Canada consultations and attends WSPS, CSSE and related activities.