One of the fundamental rules in dangerous goods storage safety is ensuring that your chemicals are properly segregated. Chemical segregation is when incompatible substances are separated to reduce the risk of the chemicals reacting with each other. Each particular class of dangerous goods has specific chemical segregation requirements that are necessary for ensuring safe storage in the workplace. However, the rules for chemical segregation are enhanced when you also store your dangerous goods in the appropriate safety cabinets.
In this post, we’ll be looking at the principles of chemical segregation, so you can create a safer work environment. We’ll also be explaining how your safety cabinets can assist in chemical segregation and other risk control measures.
What is Dangerous Goods Segregation?
Dangerous goods segregation – or chemical segregation – is the process of separating or isolating incompatible substances and those that can react dangerously. If incompatible substances and those that can react dangerously are not separated, they may react and cause harm to people, property or the environment.
Identifying Class and Subsidiary Risk
The key factor that determines the (general) chemical segregation requirements, is the class of the substances. However, we highly recommend a professional risk assessment to determine the exact needs of your site, including the packing groups and quantities of substances that you hold. You must also consider the fire hazards associated with your goods, to prevent any incidents of fires or explosions.
The Safety Data Sheet must be understood, so that you are clearly identifying the storage requirements of your goods, so that you can segregate it from other substances that may create a hazardous incident.
Refer to your Safety Data Sheet to determine if your substance is:
- Class 2.1 Flammable Gas
- Class 2.2 Non-flammable, non-toxic gas
- Class 3 Flammable Liquid
- Class 4.1 Flammable Solid
- Class 4.2 Spontaneously combustible
- Class 4.3 Dangerous When Wet
- Class 5.1 Oxidizing Substances
- Class 5.2 Organic Peroxides
- Class 6 Toxic Substances
- Class 8 Corrosive Substances
Chemicals may not fall into one category of dangerous goods. In fact, many substances also have a subsidiary (sub) risk.
Some chemicals may have a class as well as a subrisk, which will affect how you segregate your substances.
When looking at segregation requirements in your workplace, you must consider the class as well as the sub risk of each chemical. You may also have to determine the packing group of your substance, where applicable. Some packing groups have different risks, so it’s important to also consider these when looking at your storage segregation needs.
If substances within the dangerous goods class may or may not require segregation, you must refer to your Safety Data Sheet for specific details on storage requirements for that chemical.
The greater the segregation requirements for the chemical, the more danger the incompatible substances pose to each other. Therefore, it’s crucial that the segregation of chemicals is a top priority for organisation that are carrying any type of hazardous chemical or dangerous goods.
Hazards
Segregation for dangerous goods storage can be highly complex. However, you must also be aware if your onsite chemicals could create a situation including:
- Fires or explosions, caused by ignition or chemical reactions
- Reactions that result in the release of harmful vapours or gases
- The ignition of flammable substances which may cause nearby chemicals to release dangerous vapours or gases
- Corrosive materials could impact the packaging of nearby incompatible chemicals, causing further hazards
- Gas cylinders could be impacted if flammable substances catch fire, causing impact damage, human harm and the release of gases
What Segregation Tools and Resources are Available?
First and foremost, your Safety Data Sheets for every onsite chemical are the most important chemical segregation resource that you can have. Your Safety Data Sheet is full of essential information, including the class of chemical, the hazards associated with the chemical, acceptable storage and handling practices, and segregation requirements.
The second tool you need, is a chemical segregation chart or guide. You can find detailed information on chemical segregation via Safe Work Australia or the WHS legislator in your state or territory.
Access your Storemasta FREE seg chart
The third resource that we strongly suggest that you use, in your own inhouse risk assessment. This will not only allow you to identify each onsite substance and their risks (and sub risks), but it will allow your organisation to see other potential hazards that may be created when multiple dangerous goods classes are kept onsite.
In addition to these resources, there is also a range of useful materials available via Safe Work Australia and the local regulatory body in your region.
Try sourcing these free resources:
- Safe Work Australia’s Managing risks of storing chemicals in the workplace – detailed guidance material that can assist with safe storage and segregation
- Australian Dangerous Goods (ADG) Code – for information regarding chemical containers, chemical classifications and more
- WorkSafe QLD’s segregation tool – to assist with compatibility and segregation queries for your chemicals
- Australian Standards - it’s also a good idea to reference the relevant Australian Standards for each substance, as well as AS NZS 3833:2024 – The storage and handling of mixed classes of dangerous goods, in packages and intermediate bulk containers. Please note that this standard was updated in 2024 with more detailed requirements for segregation, including provision for flammable substances to reduce fire risk.
Safety Cabinets Assisting in Segregation
Once you have correctly identified the risk and sub risks of your incompatible dangerous goods — and conducted your onsite risk assessment — you will then need to determine the storage methods that provide sufficient segregation.
Your chemical control measures will be determined by the hazardous properties of the substances — and level of risk present in each case.
You should also consider that different quantities are allowed in different locations (such as laboratories), so check with the relevant Standards that relate to your workplace.
For indoor chemical storage situations, compliant safety cabinets are recognised as providing excellent hazard controls due to the double-walled sheet steel construction of the cabinet, as well as the liquid-tight spill containment sumps which prevent chemical leaks.
REMEMBER: You will also need to consider the quantities allowed for storage in each area. This is dependent on class, subrisk, packing group and, sometimes, the location of your cabinet or store.
While you may have multiple classes of dangerous goods onsite — that would generally require storage that applied the segregation distance guidelines — multiple individual chemical cabinets can be used to store each class of dangerous goods. Locate your cabinets at the correct segregation distance or consult with your risk assessment to learn more about the ideal location for each cabinet.
However, keep in mind that the compliance and safety of the cabinet — meaning, how it’s been installed, used and maintained — is key in ensuring successful chemical segregation. There’s no point installing state-of-the-art safety cabinets, each for a different chemical class, if the controls of the cabinet are compromised because it hasn’t been installed/used/maintained in a compliant manner.
REMEMBER: If your organisation uses, store or handles hazardous chemicals, you must have systems and procedures in place that prohibit incompatible materials interacting.
How Safety Cabinets Control Hazards
The features of a compliant safety cabinet enable it to provide successful segregation for the stored contents.
Some key features of a safety cabinet may include:
- Double-walled sheet steel construction – providing protection against impact damage and incompatible substances
- Thermic air barrier between the walls – to protect the contents from extreme heat and fire, which assists with minimising harm during an emergency situation
- Self-closing, close fitting doors – that assist with containment of vapours
- Perforated shelving – which allows vapours to move freely within the cabinet, instead of being trapped within a certain shelf or area of the equipment
- Liquid-tight spill containment sump – this control helps to contain spills, as well as preventing leaks or spills from coming into contact with incompatible substances nearby
REMEMBER: Each class of cabinet provides a unique set of controls that are specifically designed to minimise the hazards associated with that class. Therefore, you must never use a cabinet that’s not designed for your particular dangerous goods class, as the controls will not be sufficient to protect your people and organisation from risk.
Dangerous Goods Storage and Segregation Safety
If you’d like to learn more about dangerous goods storage, including safety cabinets, we have a comprehensive guide that can answer all of your questions. The Ultimate DG Storage Handbook is perfect for everyone from small business owners to Health and Safety Officers, and can assist you in creating a safer work environment through the implementation and maintenance of compliant storage. Get your copy now to start learning about safer chemical segregation and storage.
