Compatibility Of Class 3 Flammable Liquids With Other Classes Dangerous Goods

Originally published November 2, 2021 11:16:28 PM

Are you aware of the risks involved with storing flammable liquids with incompatible  dangerous goods? If you’re carrying chemicals in your workplace, you must consider how incompatible classes of dangerous goods can react with your flammable liquids store. The incorrect storage of incompatible chemicals can result in violent chemical reactions that can cause casualties as well as destruction to property and the environment.  

IBCWhen considering storage for Class 3 Flammable Liquids, you must understand what dangerous goods they are incompatible with.

According to AS 3833-2007, there is a difference between substances that are incompatible and those that will react dangerously. We’ll highlight these differences in detail now. 

Incompatible Substances 

Incompatible substances are those substances that are:  

  • Likely to increase risk to people, property and the environment when mixed or brought into contact with another substance
  • Listed in the Australian Dangerous Goods Code or NZS 5433 as being incompatible
  • Declared by the local regulatory authority as being incompatible 

Substances That React Dangerously

Substances that will react dangerously are those substances that react in a manner that directly creates a hazard due to the reaction. This may include producing: 

  • Violent reaction
  • Explosion
  • Potentially explosive combination of products
  • Toxic vapours or gases; or
  • Fire or rapid evolution of heat   

Using a risk management methodology to manage risks associated with hazardous chemicals

Flammable liquids must not be stored with incompatible dangerous goods that can cause a dangerous chemical reaction.

The Importance Of Chemical Segregation 

Dangerous goods that are incompatible and react dangerously with flammable liquids  require safe segregation. This can be achieved by storing the incompatible chemicals in separate safety cabinets or outdoor stores that are applicable for that class of dangerous goods.  

Install flammable cabinet

One of the key functions of a Class 3 Flammable Liquids cabinet is to provide segregation from incompatible chemicals.

However, if flammable liquids and other incompatible substances are stored in a common area — without a safety cabinet or outdoor store — they must be segregated by certain distances to avoid dangerous reactions.  

These distances are determined by the Australian Standard AS 3833-2007 - The storage and handling of mixed classes of dangerous goods and are explained in detail below: 

Class 2.1 - Flammable Gases

Flammable gases and flammable liquids are classed as incompatible. These classes of dangerous goods cannot be kept together. If these substances have to be stored in a common dangerous goods store, they will need to be kept apart by at least 5 metres. This will minimise the risk of the two classes of dangerous goods mixing and causing harm.

Three Workplace Accidents Involving Gas Cylinders That Could Have Been Avoided

Flammable gases are incompatible with flammable liquids and must be kept segregated if kept in a common dangerous goods store.

Class 2.2 - Non-Flammable, Non-Toxic Gases 

Non-flammable non-toxic gases and flammable liquids are also classed as incompatible. Class 2.2 and Class 3 dangerous goods must not be kept together. If these substances need to be stored in a common store, they will need to be kept apart by at least 3 metres.  

BEWARE: some non-flammable non-toxic gases are also oxidising gases. Oxidising gases and flammable liquids will react dangerously. For more information, refer to the section below that outlines the segregation requirements for storing oxidising agents and flammable liquids in a common dangerous goods store.     

What are Class 2.2 Non-Flammable, Non-Toxic Gases

Class 2.2 dangerous goods are incompatible with flammable liquids and must be kept 3 metres apart if sharing a common dangerous goods store.

Class 4.1  - Flammable Solids

Flammable solids and flammable liquids are incompatible. These two classes of dangerous goods must be kept apart during storage. If flammable liquids and flammable solids  must  be stored in a common store, they shall be segregated by at least 3 metres.  

Even though Class 3 and Class 4.1 dangerous goods are incompatible, AS 3833-2007 gives you the provision to store these two substances in the same safety cabinet without any segregation. This only applies to indoor dangerous goods storage cabinets and not other types of stores.  

Before these two incompatible substances are stored together, you must consult the Safety Data Sheets to determine the hazardous nature of each of the substances that you are seeking to store. You must then determine the level of risk of storing these two substances together by carrying out a dangerous goods risk assessment.  

Flammable Solids-1

A risk assessment must be conducted if you are considering storing flammable solids with flammable liquids in an indoor dangerous goods storage cabinet as they are incompatible chemicals.

Class 4.2 - Substances Liable To Spontaneous Combustion

Class 4.2 dangerous goods and flammable liquids are incompatible. These two classes of dangerous goods must not be kept together when stored. If Class 4.2 and Class 3 dangerous goods must kept in the same store, they must be segregated by a distance of at least 5 metres 

Class 4.3 - Substances Which In Contact With Water Emit Dangerous Gases

Class 4.3 dangerous goods and flammable liquids are also incompatible. These two classes of dangerous goods shouldn’t be kept together. Class 4.3 dangerous goods and flammable liquids have the potential to react dangerously and harm people and property. If these two incompatible substances must be kept in a common dangerous goods store, they shall be segregated by a distance of least 5 metres.

WET-4.3-2

Class 4.3 dangerous goods and flammable liquids are incompatible and must be segregated by 5 metres or more.

Class 5.1 - Oxidising Agents

Oxidising agents and flammable liquids have the potential to react dangerously. If flammable liquids are going to combust, they require a continuous supply of oxygen. In a combustion reaction, oxidising agents provide the necessary oxygen for flammable liquids to combust. Oxidising agents and flammable liquids must never be kept in a common store.  

Oxidising agents and flammable liquids can only be stored in a similar store if the flammable liquids and oxidising agents are separated by at least 5 metres using a vapour barrier. The spill containment sump for the flammable liquids and the oxidising agents must also be separate compounds. 

Oxidising AgentsOxidising agents have the potential to react dangerously with flammable liquids and must be stored at least 5 metres apart using a vapour barrier.

Class 5.2 - Organic Peroxides 

Organic peroxides and flammable liquids will react dangerously. Class 5.2 dangerous goods must be isolated from flammable liquids and stored in separate dangerous goods storage facilities. This isolated storage can be achieved by using relocatable chemical storage containers or indoor chemical storage cabinets 

Why organic peroxides and flammable liquids need strict segregation controls�Organic peroxides will react with flammable liquids and must be isolated using compliant storage containers or safety cabinets.

Class 6.1 - Toxic Substances 

Toxic substance and flammable liquids are incompatible. These two classes of dangerous goods must not be kept together. If flammable liquids and toxic substances are kept in a common dangerous goods storage facility, they must be separated by a distance of at least 3 metres. 

Toxic Fumes

Toxic substances are incompatible with flammable liquids and should be kept 3 metres apart if they share a dangerous goods storage facility.

Class 8 - Corrosive Substances 

Corrosive substances and flammable liquids are also incompatible. Class 8 and Class 3 dangerous goods must not be stored together. If these two incompatible classes of dangerous goods must be stored in a common dangerous goods store, they must be kept apart by at least 3 metres 

Blue drums of corrosive substance-600x300As incompatible chemicals, you must store corrosive substances and flammable liquids at least 3 metres apart if they share a common storage area.

How Are You Storing Incompatible Dangerous Goods? 

As we’ve discussed in this blog, Class 3 Flammable Liquids will react dangerously with a multitude of other dangerous substances. Therefore, it’s vital that you apply the rules of chemical segregation when you’re storing flammable liquids with other classes of dangerous goods. However, keep in mind that choosing a compliant indoor storage cabinet or outdoor store that meets the requirements of the Australian Standards allows you to safely store your dangerous goods. This is because a compliant safety cabinet is specifically designed and constructed to provide risk control measures including chemical segregation.  

Are you interested in learning more about the safe storage of dangerous goods? Our dangerous goods segregation chart is 100% free and is designed to help you identify which classes of dangerous goods require segregation. Access your copy today by clicking on the below image.

Dangerous Goods Segregation Chart

Walter Ingles

Walter Ingles Compliance Specialist

Walter is STOREMASTA’s Dangerous Goods Storage Specialist. He helps organisations reduce risk and improve efficiencies in the storage and management of dangerous goods and hazardous chemicals.

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