UN transport codes

These codes are from the “ UN Model Regulations on the Transport of Dangerous Goods ”, they are not obligatory or legally binding on individual countries, but they have a wide degree of international acceptance and form the basis of several national laws and international agreements.
They include a classification system for substances that pose a significant hazard in transportation by air, sea, rail and inland waterways. The hazards addressed include explosive, flammability, toxicity (oral, dermal and inhalation), corrosive to human tissue and metal, reactivity, radioactivity, infectious substance hazards and environmental hazards. The regulations give standards for the packaging and for any tanks that are used for transport, they also layout a system of communicating the hazards of substances using pling and marking of packages, signage on tanks, freight containers and vehicles, and the documentation and emergency response information that is required to accompany each shipment.

This is an example of a transport label. By using the Arabic numerals as the primary identifier of the substance, transport workers can find the translation into any local language.
The red diamond and the flame symbol indicates that the main transport hazard is the flammability of the product, and the number 3 at the bottom of the diamond, is the class of the product and indicates that it is a flammable liquid.
The "3YE" is the Emergency Action Code this does not appear on the packaging but will appear on the road and rail transport).
The product name “Turpentine Substitute” is called the “Proper Shipping Name” within the model regulations.

Transport Classes

There are nine main classes with six classes being split into sub classes, these classes are used to group the transport codes. I have also added the symbol to be used for the class, where there is more than one symbol it is because the sub-class can be broken down into smaller classes as specified within the model regulations.

Classes	Description
1	Explosive
1.1	Substances and articles which have a mass explosion hazard
1.2	Substances and articles which have a projection hazard but not a mass explosion hazard
1.3	Substances and articles which have a fire hazard and either a minor blast hazard or a minor projection hazard or both, but not a mass explosion hazard
1.4	Substances and articles which present no significant hazard
1.5	Very insensitive substances which have a mass explosion hazard
1.6	Extremely insensitive articles which do not have a mass explosion hazard
2	Gases
2.1	Flammable gases
2.2	Non-Flammable, non-toxic gases
2.3	Toxic gases
3	Flammable liquids
4	Flammable solids; substances liable to spontaneous combustion; substances which, on contact with water, emit flammable gases
4.1	Flammable solids; self-reactive substances; solid desensitised explosives
4.2	Substances liable to spontaneous combustion
4.3	Substances which in contact with water emit flammable gases
5	Oxidising substances and organic peroxides
5.1	Oxidising substances
5.2	Organic peroxides
6	Toxic and infectious substances
6.1	Toxic substances
6.2	Infectious substances
7	Radioactive material
8	Corrosive substances
9	Miscellaneous dangerous substances and articles

Group 9 is a catch all for hazardous materials that are not in any other classes

The table below is an example of what can be put together from multiple data sources.

UN No.	Class	Packing group	Labels	Tunnel code	EAC	Proper Shipping Name
1295	4	I	4.3, 3, 8	B/E	4WE	TRICHLOROSILANE
1299	3	III	3	E	3Y	TURPENTINE
1321	4	I	4.1, 6.1	B	1W	DINITROPHENOLATES, WETTED with not less than 15% water, by mass
1469	5	II	5.1, 6.1	E	1Y	LEAD NITRATE
1556	6	I, II, III	6.1	E	2X	ARSENIC COMPOUNDS, LIQUID, N.O.S inorganic, including arsenates, n.o.s.; arsenites, n.o.s.; arsenic sulphides, n.o.s.; and organic compounds of arsenic, n.o.s.
1993	3	I, II, III	3	D/E	3YE	FLAMMABLE LIQUIDS, N.O.S.

The table columns give the following information: -

• UN No. - The United Nations transport code, in North America (Canada, USA and Mexico) the code might be prefixed by "NA" rather than "UN". In the USA this is also known as the DOT code.
• Class - This is the main class that the transport code is grouped in.
• Packing Group - The packing group(s) that the transport code can be used with.
• Labels - The sub-class(es) for the product which then tells you which symbol(s) will be used.
• Tunnel code - This does not have to be shown under the regulations. The transport company should know this from the U.N. code as they require the code so that they can arrange the route. For more information on tunnel codes see this document from the Road Haulage Association.
• EAC - Emergency Action Codes, you will see this on the transport vehicle or train these are set out in The Dangerous Goods Emergency Action Code List 2011 . These codes are used by emergency responders who can look up the code to see what extingishing media can safely be used, along with the safety precautions to take.
• Proper shipping name - The text in capitals is the name to appear on labels. The lower case text gives you information to help select the correct code when there are different codes or packaging types for the same product/substance. Where there is "N.O.S." (Not Otherwise Specified) in the proper shipping name then the correct substance name must be included i.e. UN1993 FLAMMABLE LIQUIDS, N.O.S. (ETHANOL).