ADR Hazard Diamonds & Classes

Hazardous Chemicals and Dangerous Goods are transported throughout the United Kingdom, by road and rail every day. These goods include dangerous chemicals such as:

• Acids 
• Toxins and carcinogenic substances 
• Explosives 
• Radioactive materials 
• Inflammable liquids 
• Volatile chemicals likely to spontaneously combust or react with air, water etc.  
• Inflammable, poisonous or compressed gases 

Although the Health and Safety Executive is primarily responsible for enforcing the many regulations designed to ensure safety while these substances are in transit, it is the members of the emergency services who will have to deal with the consequences of any incident. 

Laid out below are the UN Hazard Classes and Danger Signs. To find out what each class number is and what each sign represents, please refer to the list at the foot of this page.  

DANGER LABELS

The following are danger labels that will be displayed on vehicles, containers and packaging during the transportation of dangerous goods. 

Class 1 – Explosive substances or articles 

Class 2 – Gases 

Class 3 – Flammable Liquids 

Class 4.1 – Flammable Solids, self-reactive substances and de-sensitised explosives 

Class 4.2– Substances liable to spontaneous combustion 

Class 4.3– Substances which, in contact with water, emit flammable gases 

Class 5.1 – Oxidising Substances 

Class 5.2 – Organic Peroxides 

Class 6.1 – Toxic Substances 

Class 6.2 – Infectious Substances 

Class 7 –Radioactive Material 

Class 8 –Corrosive Substances 

Class 9 –Miscellaneous 

Under the requirements of the 2019 editions of the European Agreements Concerning the International Carriage of Dangerous Goods by Rail (RID) and by Road (ADR), all goods classified as dangerous in carriage whether or not assigned to another class may need to have the Environmentally Hazardous Substance (EHS) mark displayed on their packaging if they meet the EHS criteria contained in 2.2.9.1.10 of ADR and RID. 

The following are additional danger labels that are used

in the transportation of dangerous goods.  

Environmental Hazardous Substance mark 

The following are marks that may appear on vehicles during the transportation of dangerous goods and would appear in addition to the danger labels at 1.2.1

 

 

UNITED NATIONS (UN) HAZARD CLASSES & INFORMATION 

Class Number	Hazard Class Information
Class 1	Explosive
1.1	Substances with a mass explosion hazard
1.2	Substances which present a projection hazard but no mass explosion hazard
1.3	Substances which present both a fire hazard and a minor blast or projection hazard (or both) but not a mass explosion hazard
1.4	No significant hazard
1.5	Very insensitive substances with a mass explosion hazard
1.6	Very insensitive articles with no mass explosion hazard
Class 2	Gases
2.1	Flammable gases
2.2	Non-flammable, non-toxic gases
2.3	Toxic gases
Class 3	Flammable liquids
Class 4	Flammable solids
Class 4.1	Flammable solids, self-reactive substances and solid desensitised explosives
Class 4.2	Materials liable to spontaneous combustion
Class 4.3	Substances which, in contact with water, release flammable gases
Class 5	Oxidizing substances and organic peroxides
Class 5.1	Oxidizing agents
Class 5.2	Organic peroxides
Class 6	Toxic and infectious substances
Class 6.1	Toxic substances
Class 6.2	Infectious substances
Class 7	Radioactive substances and articles
Class 8	Corrosive substances
Class 9	Miscellaneous dangerous substances and articles. Class 9 includes items such as asbestos, automotive airbags, lithium batteries and environmentally hazardous substances which don't fit into any of the other 8 classes.