Why organic peroxides and flammable liquids need strict segregation controls 

Jul 8, 2020 Posted by Walter Ingles

Class 5.2 Organic peroxides are widely used on industrial and manufacturing worksites for a range of applications — often involving fibreglass and resins, reinforced plastics, cosmetics, food manufacturing processes and textiles. But many worksites that use organic peroxides, also carry varying quantities of flammable and combustible liquids — a chemical hazard class that reacts dangerously with organic peroxides. In this blog we’ll be highlighting some of the key storage requirements for both organic peroxides as well as flammable liquids. 

REMEMBER: You have a responsibility under Australian WHS Regulations to keep hazardous chemicals stable on the job site and ensure they do not become unstable, decompose, or significantly increase the risk associated with another chemical. 


Storing organic peroxides and flammable liquids  

Organic peroxides and flammable liquids should be isolated from each other according to the guidelines contained on the Safety Data Sheets (SDSs) for each chemical — usually at least 5 metres separation distance. But using purpose-built indoor safety cabinets for the chemicals can greatly reduce these separation distances, meaning a more efficient use of space for your business. 

1. Cabinets for organic peroxides

Indoor safety cabinets for Class 5.2 Organic Peroxides must be made from double-walled sheet steel and fitted with doors that closes automatically. The doors must be held in place by a friction or magnet type lock that can release if pressure builds up in the cabinet. Door catches and hinges must never be made of plastic. 

ESSENTIAL REFERENCE: AS2714:2008 — The storage and handling of organic peroxides 

2. Flammable liquids cabinets

Flammable liquids safety cabinets are also made from double-walled sheet steel, but all materials and componentry must be able to withstand at least 850°C. This creates a heat barrier between the chemicals and any external fires. Cabinet doors must close automatically and create a tight fit to seal the contents from flames and heat radiation. 

ESSENTIAL REFERENCE: AS1940:2017 –- The storage and handling of flammable and combustible liquids 

REMEMBER: Safety Cabinets for organic peroxides and flammable liquids have different construction specifications, so make sure the cabinets are never recommissioned or used for other hazard classes.  



Identifying workplace compatibility hazards 

Of course, keeping Class 5.2 Organic Peroxides and Class 3 Flammable Liquids safely isolated in indoor cabinets is only one step to onsite chemical safety. You also need to identify, evaluate and manage all chemical handling practices and other operational tasks where these incompatible chemicals could come in contact with one another. A risk assessment could begin like this: 

Step 1 — identify organic peroxides 

Start with a site inspection or walk-around that identifies everywhere organic peroxides are used, stored, or handled. Organic peroxides can be very sensitive to heat and changes in temperature, so pay attention to the location of the stores. At the same time remember that ignition sources and combustibles should never be stored within 3 metres of an organic peroxide safety cabinet. 

Step 2 — identify flammable liquids 

Now consider all the flammable and combustible liquids you have onsite — this could be anything from a jerrycan of petrol or diesel, to paints, solvents, oil, grease and pesticides. Look at where flammable liquids are decanted, or where fuel-driven machines are filled or operated. Are there organic peroxides nearby? 

Step 3 — identify potential contact points 

Now compare the two chemical lists and identify all the places (or ways) where the chemicals could contact one another and cause a dangerous reaction. This includes during delivery and chemical intake, production, warehouse and transfer, decanting, mixing, spill clean-up and disposal. 

REMEMBER: One of the most common hazards is workers and external contractors carrying out maintenance work (eg welding, grinding, cutting) or bringing ignition sources near chemical safety cabinets. 



Taking corrective action 

You’ll need to take corrective action to address all the contact hazards — your aim will be to eliminate the hazards where possible. Corrective actions may involve: 

  • Housekeeping: keeping the site maintained so there is no build-up of combustibles, chemicals are disposed of promptly and safely, chemical spills are dealt with immediately, and chemicals are put away into the store when not being used. 
  • Work procedures: implementing clear work procedures for all workers and contractors who are handling chemicals, as well as workers who carry out maintenance work around the job site.  
  • Restricted access: limiting access to organic peroxides and flammable liquids stores. 
  • Site inductions: ensuring that everyone who enters the worksite is aware of the site rules, and chemical hazards. 
  • Chemical safety training: providing ongoing training for workers who handle (or are exposed to) organic peroxides and flammable liquids. 
  • Site audits and assessment: introducing regular site inspections, safety audits, and risk assessments. 

REMEMBER: Many organic peroxides are sensitive to temperature, so always check the Safety Data Sheet (SDS) for any temperature controlled storage recommendations. You are required under Australian WHS Regulations to store any temperature reactive chemical within safe temperature ranges. 


Next steps 

A risk assessment is critical when your worksite carryings multiple classes of Dangerous Goods — especially Class 5.2 Organic Peroxides and Class 3 Flammable Liquids. We recommend downloading our free eBook Essential Considerations When Storing Flammable Liquids Indoors for a complete discussion on the chemical risk assessment process as well as the most up-to-date chemical storage requirements and best practices. Download and read it today. Essential Considerations when Storing Flammable Liquids Indoors download Free eBook

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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