UN Marking Code - S

After the relative density or maximum gross weight numbers, there are two possible markings. In A14.1, the examples given are "100 or S":

• For single packagings intended to carry liquids, the number is the maximum hydraulic test pressure which the design type was able to withstand, shown in kPa rounded down to the nearest 10 kPa (determined by a hydraulic test).
• For packagings intended to carry solids or inner packagings, the letter S is used.

For air shipments of packagings intended to contain inner packagings, refer to A3.1.7.1; for plastic inner packagings make sure the requirements of A3.1.3 are met.

After the hydraulic test pressure or "S" designation, there are two possible types of markings, the last two digits of the year in which the packaging was manufactured are shown. This can appear as a graphic.

For packagings types of 1H1, 1H2, 3H1, and 3H2, they must also be marked with the month of manufacture. The month can be marked on the packaging in a different place than the UN specification packaging marking.

This is followed by the country authorizing the allocation of the mark.

To learn more about Shipping HAZMAT visit our Shipping HAZMAT By Military Aircraft Online Training web page.