Dangerous goods which fall outside of limited quantities usually have to be packed in special packages known as “UN certified packaging”. This certification implies that the packages have been tested to withstand a variety of conditions to ensure if damaged they will maintain their integrity.
There is a variety of different tests depending on the type of packaging and we will concentrate on combination (inner and outer) and single packaging which are less than 400 kgs nett. The three common tests are leak proof (for liquids), stack and drop. Some packaging is also pressure tested.
Packages which have been successfully tested will have a code embossed on them. Typical example is - UN/4G/X11/S/08GB/VL0582
UN UN certification mark
4G Type of box (fibreboard)
X11 Packing group and nett mass
S Intended for solids or inner package
08 Year of manufacture
GB Country of manufacture
VL0582 Supplier identification
There are codes for different types of packaging and the Packing Group (where relevant) of the material to which the packaging has been tested is X, Y and Z, X being PGI, Y, PGII, Z, PGIII.
UN certified packages can be reconditioned and will show in the code the year of reconditioning, the letter “R” and if retested for leakproofness the letter “L”.
Packaging Instructions are given in the dangerous goods list in the relevant mode regulation. The instruction will advise what type of packaging can be used against the UN number and weight allowed depending on packing group.