Minimum Height of UN Numbers on Packages

Are my eyes getting better with age or did something change? Something changed.

New to the regulations this year is a statement regarding the size of text on labels for dangerous goods. Both IATA (Air) and IMDG (Marine) have made changes to reflect the UN Model Regulation that become mandatory as of January 1st, 2014. Please reference “UN Model Regulations: 17th Edition; Section (Vol 2. pg. 139)”, “IATA: 54th Edition; Section: – Size (pg. 619)” and “IMDG Code: 2012 Edition; Section: (Vol 1. pg. 244)” to find the following information.

As of January 1, 2014, mandatory size for “UN number” and letters “UN”:

Letter height requirements

Some things to note:

  1. The way this is written is such that the UN number and letters “UN” MUST be at least the size specified above whereas other package markings SHOULD be that minimum size.
  2. Other package markings include the proper shipping name, technical name, the word “Overpack”, and any other markings.
  3. For IMDG, cylinders marked in accordance with the 2010 version of IMDG are acceptable until no later than July 1st, 2018 (and only if marked by December 31st, 2013), otherwise the sizing requirements must be followed.

Letter height requirements

Shipping Limited Quantities by Air

When shipping limited quantities (LQ), you do not need to use a UN specification package. But what specs should the package you want to use meet? IATA section 2.7.6 states that the shipper must do a series of drop tests and a 24 hour stacking load test before using the package. Does this then mean that the shipper is done?

Section states that 5.0.2 through 5.0.4 must be met, except for,,, and Section 5.0.2 is the general packing requirements. The performance test requirements for a package, also known as UN specification packaging, section does not apply as well as  After reading these sections, does this mean the shipper can use their package? Not quite, there is another section to read – Here it states that the outer packaging must meet the construction requirements of section 6.2. For combination packages, the most used outer packaging is the fibreboard box. In section 6.2.12, it states that the box must be subjected to the Cobb test. This is a test to determine the water absorbency of the fibreboard box, where the increase in weight cannot exceed 155 g/m2.

Are shippers aware of this requirement? And how are they to determine this when selecting a packaging to use? It might just be easier to use a UN specification package and send the shipment Continue Reading…