Must vs. May

In the regulatory world, things are not always as clear as they seem at first glance. One example of this is the use of the words must, may, shall and should. They seem pretty straightforward, but if interpreted incorrectly, they could lead you down the road of non-compliance, or leave you scrambling to comply with something that is not actually required.

Let’s imagine we are shipping an urgent package containing a sample of a virus that is included in division 6.2. We are shipping it by air according to the IATA Dangerous Goods Regulations. We have packaged the sample according to the regulations but when we go to label the package, we find that someone used the last label on the roll. We go hunting around the office to see if we can find more labels. The only 6.2 labels we can find are some that look similar to the ones we have always used, but they are not exactly the same. The labels that we normally use have text referring to notification to the public health authority in case of damage printed in the center. The labels we just found don’t have the text. Can we use them? Let’s see what the regulations say…

Section 7.3.15 of IATA shows a 6.2 label without the text. Below the picture of the label it states: "The lower part of the label should bear the inscription: INFECTIOUS SUBSTANCE In case of Damage or Leakage Immediately Notify Public Health Authority". Do we need to keep looking for labels that have the text? NO! Section 1.3.1.3 of IATA states: "In these Regulations, the words "shall" and "must" are used to indicate a mandatory requirement. The words "should" and "may" indicate a preferred requirement and are not binding." Since section 7.3.15 uses the word "should", we can use the labels without the text and still be compliant.

Each transport regulation has similar usage of must, may, should and shall. Make sure that you are checking the regulations carefully, as well as confirming any carrier or country specific requirements, to ensure that you aren’t causing yourself unnecessary violations or delays.