An outline of the dangerous goods classes, divisions, packing groups and subsidiary risks
May 17, 2018

An outline of the dangerous goods classes, divisions, packing groups and subsidiary risks

Walter Ingles Walter Ingles

Dangerous goods are divided into 9 classes (and several subdivisions) based on the predominate hazard presented by the dangerous substance. The hazard presented by a dangerous substance is due to the substances chemical and physical properties. The different dangerous goods classes and subdivisions are outlined below:

Class 1: Explosives

  • Division 1.1: Substances and articles which have a mass explosion hazard
  • Division 1.2: Substances and articles which have a projection hazard but not a mass explosion hazard
  • Division 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
  • Division 1.4: Substances and articles which present no significant hazard
  • Division 1.5: Very insensitive substances which have a mass explosion hazard
  • Division 1.6: Extremely insensitive articles which do not have a mass explosion Hazard

Class 2: Gases

  • Division 2.1: Flammable gases
  • Division 2.2: Non-flammable, non-toxic gases
  • Division 2.3: Toxic gases

Class 3: Flammable liquids

Class 4: Flammable solids; substances liable to spontaneous combustion; substances which, on contact with water, emit flammable gases

  • Division 4.1: Flammable solids, self-reactive substances and solid desensitised explosives
  • Division 4.2: Substances liable to spontaneous combustion
  • Division 4.3: Substances which in contact with water emit flammable gases

Class 5: Oxidizing substances and organic peroxides

  • Division 5.1: Oxidizing substances
  • Division 5.2: Organic peroxides

Class 6: Toxic and infectious substances

  • Division 6.1: Toxic substances
  • Division 6.2: Infectious substances

Class 7: Radioactive material

Class 8: Corrosive substances

Class 9: Miscellaneous dangerous substances and articles


Subdivisions

Some classes of dangerous goods are further classified into subdivision. While all the substances within a class have a similar main risk, they can sometimes be classified further according to their specific chemical characteristics and associated risks. The dangerous goods classes that are divided into subdivisions include:


Packing Group

Some dangerous goods classes and divisions are also divided into packing groups. The packing groups within a dangerous goods class specify the degree of danger associated with the substances with the class. There are three different packing groups. These include:

  • Packing Group I: Substances presenting high danger
  • Packing Group II: Substances presenting medium danger
  • Packing Group III: Substances presenting low danger

Each of the dangerous goods classes and their associated packing groups are outlined in the table below:

Dangerous Goods Class/Division

Packing Groups

Class 1 - Explosives

Not applicable

Division 2.1 - Flammable Gases

Not applicable

Division 2.2 - Non-flammable Non-toxic Gas

Not applicable

Division 2.3 - Toxic Gas

Not applicable

Class 3 - Flammable Liquids

I, II & III

Division 4.1 - Flammable Solids

I, II & III

Division 4.2 - Spontaneous Combustibles

I, II & III

Division 4.3 - Dangerous When Wet

I, II & III

Division 5.1 - Oxidising Agents

I, II & III

Division 5.2 - Organic Peroxides

II Only

Division 6.1 - Toxic Substances

I, II & III

Division 6.2 - Infectious Substances

Not applicable

Class 7 - Radioactive Substances

Not applicable

Class 8 - Corrosive Substances

I, II & III

Class 9 - Miscellaneous Dangerous Goods

II & III




Subsidiary Risks

If the chemical and physical properties of a dangerous substance present more than one particular hazard, this substance will be assigned to the dangerous goods class that matches its main hazardous property. The other hazards associated with the dangerous substance are referred to as the subsidiary risks.  Some examples of dangerous substances with subsidiary risks are outlined below:

Hydrogen Peroxide is a strong oxidising agent that also has corrosive properties. It meets the classification criteria for both Division 5.1 Dangerous Goods and Class 8 Dangerous Goods. Hydrogen Peroxide has a greater oxidising ability than corrosion ability and therefore it is assigned to Division 5.1 as its dangerous goods classification. The Australian Dangerous Goods Code also shows it as having a subsidiary risk of Class 8 to cover its corrosive hazard.

Chlorine Gas is a toxic gas that also has corrosive properties. It meets the classification criteria for both Division 2.3 Toxic Gases and Class 8 Corrosive Substances. The major risk associated with chlorine gas is it’s toxicity and therefore it is assigned to Division 2.3 - Toxic Gases as its dangerous goods classification. The Australian Dangerous Goods Code also identifies chlorine gas as having a corrosive hazard by assigning it a subsidiary risk of Class 8.

Next Steps

There are 9 different classes of dangerous goods and each class has a number of classification factors such as subdivisions and packing groups. The dangerous substances within each class can also have a number of subsidiary risks. Dangerous substances that have subsidiary risks meet the classification criteria for more than one dangerous goods class. To ensure that your organisation is protected from the risks associated with dangerous substances, it is very important that you are well aware of the different chemical and physical properties associated with each dangerous goods class. If you would like more information on the 9 different classes of dangerous goods, download our FREE eBook by clicking on the image below.  

Dangerous Goods - What are they?

Walter is STOREMASTA’s Dangerous Goods Adviser. He loves helping business reduce the risk that Dangerous Goods pose upon their employees, property and the environment through safe and compliant dangerous goods storage solutions.

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