When you are storing flammable liquids in the workplace, it is very important that you store them well away from other incompatible classes of dangerous goods. Incompatible classes of dangerous goods have the potential to react with flammable liquids and cause violent chemical reactions. These reactions can harm people, property and the environment. Of the eight other classes of dangerous goods, there are some that are incompatible with flammable liquids and other that will react dangerously. According to AS 3833-2007, there is a difference between substances that are incompatible and those that will react dangerously.
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:
- Producing an explosion
- Being violent
- Producing a potentially explosive combination of products
- Producing toxic vapours or gases; or
- Producing fire or rapid evolution of heat
Segregation
Dangerous goods that are incompatible and react dangerously with flammable liquids can be segregated by storing them in separate safety cabinets or outdoor stores. If flammable liquids and other incompatible substances have to be stored in a common store, they must be segregated by certain distances to avoid dangerous reactions. These distances are determined by the Australian Standard AS3833-2007 - The storage and handling of mixed classes of dangerous goods. We will now discuss the compatibility of flammable liquids with other classes of dangerous goods.
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 3 metres. This will minimise the risk of the two classes of dangerous goods mixing and causing harm to people, property and the environment.
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. BE AWARE - 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.
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 have to be stored in a common store, they must 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 dangerous goods 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.
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 have to be kept in the same store, they must be segregated by at least 5 metres.
Class 4.3 - Dangerous when wet
Class 4.3 dangerous goods and flammable liquids are also incompatible. These two classes of dangerous goods should not not 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 have to be kept in a common dangerous goods store, they must be segregated by at least 5 metres.
Class 5.1 - Oxidising agents
Oxidising agents and flammable liquids will 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.
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.
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 have to be kept in a common dangerous goods storage facility, they must be kept apart by at least 3 metres.
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 have to be stored in a common dangerous goods store, they must be kept apart by at least 3 metres.
Next Steps
As Class 3 flammable liquids will react dangerously with a number of other dangerous substances, it’s very important that you apply the rules of segregation when you are storing flammable liquids with other classes of dangerous goods. If you would like a free dangerous goods segregation chart to help identify which classes of dangerous goods require segregation, go ahead and download our free dangerous goods segregation chart by clicking on the image below 👇.
