The UN number plays an important role when metal and plastic packaging for hazardous goods are bottled and put into circulation. This internationlly valid number contains all important information about the classification of the transported dangerous goods such as material, kind, form and "resilience" of the packaging and details about the producer. The UN number is imprinted directly during the production of metal packaging and considered in the mould for plastic packaging. Every UN number is specifically valid for the respective packaging and thus nearly as unique as a fingerprint.
The UN number is one of the criteria for finding the correct packaging. When hazardous goods are carried on the road, by ship or by rail the classification of the hazardousness of the substance and the legal provision for the transport have to be clarified. It's recommended not to rely on old safety data sheets. Moreover you should consider the actual regulations for dangerous goods as they may changed since the last transport. At the moment there are three valid regulations in Germany: the "Gefahrgut-Verordnung See" (GGVSee) for ships dating back to 2003, the "Gefahrgut-Verordnung Straße, Eisenbahn und Binnenschifffahrt" (GGVSEB) for roads, railway and inland navigation that was revised in 2019 and the "Gefahrgut-Ausnahmeverordnung" (GGAV 2002) for exceptional dangereous adpoted in 2002.
So the UN number helps to clarify the miminum requirements for the respective hazardous goods regarding the construction, equipment, approval, examination and label. It's also important to pay attention that the containers with UN number must always be complete to be recognized as containers for hazardous goods. Thus you need e.g. a for the transport of chemical-technical goods you don't only need a hobbock, but also the respective lid and accessories like clamping rings and plastic split pins to close the hobbock tightly and guarantee a safe transport.
To exclude confusions largely a UN number is structured so that a letter follows a number and a number follows a letter. The form of packaging takes the first place within the UN number and is defined by a numeral as follows:
1 = barrel
2 = stays open
3 = canister
4 = box
5 = bag
6 = combined packaging
7 = stays open
0 = thin steel sheet packaging
Another part of the UN number is the indication of the material. This is e.g. important for police and fire brigade in case of fire because every material reacts in a different way to heat deveolopment. Dosen-Zentrale sells dangerous good packagings that are made of plastic or metal that supports higher temperatures. These are the material indications within the UN number:
A = steel
B = aluminium
C = natural wood
D = plywood
F = wooden fibre material
G = cardboard
H = plastic
L = textile
M = paper, multi-layered
N = glass
P = porcelain, stoneware
The third place within the UN number is reserved for the type of packaging:
1 = irremovable lid
2 = removable lid
The dangerousness of the transported good is the most important information within the UN number. This indication is called packing group. The UN number distinguishes three levels:
X = very dangerous
Y = dangerous
Z = less dangerous
Behind the packing group the maximum test pressure is indicated within the UN number. This pressure serves to validate the tightness of the dangerous good packaging. The value is stated in kilopascal (kPa) and the UN number expresses it always using three numerals, e.g.:
095 = maximum test pressure of 95 kPa
Naturally liquid hazardous goods are more difficult to handle than solid ones. That's why the nature of the dangerous substance is obviously also a part of the UN number:
S = solid
L = liquid
The indication of the production year is important as it allows to draw conclusions about the state and transportability of the packaging. Please note that the UN number doesn't indicate the whole year, but only the last two numerals, e.g.:
18 = produced in the year 2018
Now there is an exception within the UN number. You find two indications composed by letters defining the country where the packaging was registered and the issuing authority. In Germany the competent authority is normally the Bundesanstalt für Materialforschung und -prüfung in Berlin
D = registration in Germany
BAM = approved by Bundesanstalt für Materialforschung und -prüfung