How to segregate incompatible hazardous chemicals
Jul 11, 2018

How to segregate incompatible hazardous chemicals

Walter Ingles Walter Ingles

Many chemicals used in the workplace are incompatible — meaning they can create violent reactions if they’re mixed (or sometimes even just contact one another). Mixing incompatible chemicals like bleach and ammonia creates dangerous vapours; water or steam contacting calcium oxide (lime) generates heat; and oxidisers contacting flammables cause fires and explosions. This blog outlines the steps required to properly segregate hazardous chemicals at your worksite to prevent dangerous chemical reactions and emergency situations.

REMEMBER: contrary to Bruce Springsteen’s song ‘Dancing in the Dark’, you CAN start a fire without a spark. Make sure your self-reactive chemicals are segregated properly so they don’t.

Identify each chemical you store at your worksite

Correctly identifying each of the chemicals used and stored at your worksite is the first (and arguably the most critical) step to safely segregating incompatible chemicals. You’ll do this by creating a master register to document each and every chemical you have onsite and collate a copy of all the Safety Data Sheets (SDSs). You may have to conduct a walk-around to physically identify each chemical, taking the time also to note how they are labelled and stored.

Once you have your list you can take a deeper dive, and identify (for each of the chemicals) their …

  • Hazard class
  • Physical and chemical properties
  • Stability and reactivity

This information is specialised and may not be printed on the label, so you’re definitely going to need to read that SDS carefully. Now it’s time to work out which chemicals require segregation and how you are going to do it.

TIP: Conduct visual inspections of hazardous chemicals and their containers regularly — noting worn or missing labels, damaged containers, out-of-date chemicals.

Determine Segregation Requirements

To begin your segregation scheme, you should group chemicals according to their hazard class. But also remember it’s not simply a matter of placing all the flammable liquids in one corner and the flammable solids in another — most chemicals have multiple hazards.

Things get tricky when you have (for example) flammable solids that are also a corrosive, or a flammable liquid that is also a toxic substance. Depending on the individual chemical properties you may still be able to store the corrosive with the flammables, but it may need to be isolated within the flammables storage area. Ultimately your decision will be based on a complete hazard analysis and risk assessment that identifies the consequences of an accidental release or dangerous chemical reaction.

Here at STOREMASTA we have developed a free Dangerous Goods Segregation Chart to help you quickly identify chemical hazard classes that are incompatible, and those which must be either isolated or completely separated. The chart is really easy to navigate, and in less than a minute you can work out that flammable solids must be stored at least 3 metres from flammable liquids, and in a separate compound or building (at least 5 metres apart) from flammable gases. Feel free to download this Dangerous Goods Segregation Chart.

TIP: Your segregation scheme must also include procedures for safe removal and disposal of hazardous chemicals so they don’t mix with incompatible substances.

Implement segregation and risk control

Now it’s time to implement the plan and actually setup those storage areas. Again, the actual control measures you use and how the chemicals are separated will depend on the chemicals you use, the hazards they possess, how often they are used, as well as any special features of your workplace.

Here are some general tips and reminders:

  • Chemical quantities should be kept to a minimum
  • Make sure hazardous chemicals are correctly labelled. This prevents substances being placed in the wrong containers causing accidental mix-ups.
  • Use the correct chemical storage containers for the hazard class: flammable cabinets, corrosive cabinets, gas bottle cages, stainless steel cabinets etc.
  • Develop safe and consistent operating procedures and your train staff properly. There is no point segregating flammables if staff bring unsafe machinery and potential ignition sources into chemical storage areas.
  • Use safety cabinets that contain their own ventilation system; a liquid tight sump to contain spills; and doors that automatically release in the event of a build-up of pressure inside the cabinet.
  • Install eye wash stations, dedicated PPE cabinets and safety showers.
  • Remember to keep container lids, safety cabinets, cages, and all chemical storage areas secured.

Tip: Involve the manufacturer or supplier of the chemicals as well as professional safety consultants. They can recommend segregation methods that have been successful at other worksites, and fully explain the WHS legislation that applies to the chemical hazards in your workplace.

Next Steps

If you haven’t already downloaded our free Dangerous Goods Segregation Chart grab it now. We also recommend you read our free eBook How to manage the risk of Hazardous Chemicals in the workplace. It’s more than an eBook:

  • It outlines our step-by-step Methodology for managing the risks associated with hazardous chemicals.
  • It’s a sure way to meet your WHS obligations for chemical safety.

Download and read this eBook today by clicking on the image below:

How to manage the risk of hazardous chemicals in the workplace

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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