Deciphering UN Packaging and Overseas BMC Certs

I’m going to ask Lonnie Jaycox or some help on this one. Lonnie is an expert in this field and often presents webinars for AICC on these topics. We are both members of the Institute of Packaging Professionals. Because this is a multifaceted question I’ll organize this response into segments for better readability.


Tim asks,

Can you direct me to a place that can answer questions related to this overseas BMC cert stamp? Our customer is stating the following…

“We ship DOT 39 cylinders  with the shipping name of UN 1956 compressed gases or UN 3500 chemicals under pressure and these products do not have to use UN certified packaging.  These UN ID numbers do not have associated packing groups so we are not required to test the boxes.”

Lonnie answers:

I am assuming that the material is properly classified, authorized and packaged in the DOT cylinders.

In the case of Class 2 materials, the cylinders themselves are the “UN certified packaging”.  There is only one case I know of where a compressed gas in a cylinder would require a tested outer packaging.  This would be aerosols packaged under the ICAO TI when not offered for shipment as an LQ in that regulation.  I do not think this applicable here, so yes, there would be no need for a tested 4G packaging system for these DOT 39 cylinders.

“What is required:


Lonnie answers:

The above phrase is specified in 173.306 for aerosols.  Below is the text from 173.301(a)(9) applicable to DOT 39 cylinders in strong non-bulk outer packagings:

From 173.301(a)(9)

(9) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong non-bulk outer packagings. The outside of the combination packaging must be marked with an indication that the inner packagings conform to the prescribed specifications.

 You may not want to use the aerosol marking.  You may want to use the language in 173.310(a)(9) for DOT 39: “INNER PACKAGINGS CONFORM TO PRESCRIBED SPECIFICATIONS”

I have not looked for any interpretations that would indicate that the language is equivalent.  It may make no difference to the regulator, but I cannot say that categorically without looking deeper into it. 

 In looking at this system, it also appears that the outer box of this system meets the definition of an “OVERPACK” in 173.25, and should also be marked as such [“OVERPACK” in letters at least 12mm high.  Again, without looking deeper into this, it may be a redundant marking; but the box covers up the specification marking of the cylinder and that triggers the requirements of 173.25(a)(4)

  1. Use strong outer packaging

Lonnie answers:

A fiberboard box properly made of material suitable for its size and weight would be considered a strong outer packaging.

Do we need to put any UN logo with the numbers on the carton? If so, what goes into determining what numbers are needed?

Lonnie answers:

UN specification marking on the overpack would not be done unless the system was tested as a combination packaging system.  That is not what is being proposed here.  I do want to remind everyone that all required marking and labels (hazard communication) on the cylinders, that are covered up by the box must be reproduced on the outer packaging, unless there are specific exceptions.


I see lots of packaging companies offering UN boxes but obviously those boxes haven’t been tested for any specific product.

Lonnie answers:

While there are available on the market pretested packagings for hazardous materials that meet some generic packaging authorizations; and as such may be useful for wide variety of let’s say liquid hazardous materials of PG II (tested to meet the requirements of 173.202 with water or an equivalent); they still must be used in their tested configurations, or an allowed variation.


Could you direct me to a simple to understand website that might help us understand what has to be done?

Lonnie answers:

If such as website was available, many transport compliance specialists would be looking for new careers.

If you are going to work on hazardous material transportation packaging projects, the first requirement is to get the required training; that is a requirement of the regulations.

Compressed gasses are among the most difficult hazardous materials to package and ship.  Fortunately, as I noted above, there is almost no place in that space for 4G boxes. 

Getting the cylinders properly filled and authorized is the big job.  A 4G box cannot fix a problem there. 

Also, making certain that the marking and labeling is properly done on the appropriate packaging is very important and will be part of the box supplier’s responsibilities.

Lonnie Jaycox (Jaycox Consulting, LLC) provides consulting services to packaging manufacturers and specializing in complex packaging and regulatory issues such as the project discussed in this post. Lonnie also provides training for box makers on these and other topics as well. You can click here to email Lonnie, or may contact him by calling 1-314-696-0211.

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