Fire precautions and fire response when dealing with spills of hazardous substances

Spills involving hazardous substances don’t just create a slip hazardous or environmental risk; they can also present a serious fire and explosion hazard. Many fuels, solvents, and chemicals release flammable vapours that can ignite quickly, often before anyone realises the danger.

Understanding fire precautions and correct fire response during a spill is critical to protecting people, property, and the environment. You can find specific response action within the safety data sheet for the hazardous substances you are using, but bear in mind that this might not define outcomes when two or more hazardous substances are mixed.

Why Spills Create Fire Risk

Many hazardous substances are flammable or give off vapours that ignite easily. These vapours can:

• Be heavier than air, pooling at floor level
• Travel long distances to ignition sources
• Accumulate in low or enclosed areas
• Ignite suddenly from sparks, heat, or static electricity

A small spill can therefore lead to a large fire if basic precautions are missed.

It’s a requirement from WorkSafe that workers using hazardous substances must have fire extinguisher training and dangerous goods handler training to help them respond quickly and effectively to these risks.

Common Ignition Sources During Spill Incidents

During spill response, fire risk often increases due to everyday activities and equipment, including:

• Forklifts and mobile plant (forklift training often highlights these dangers) – shut them down
• Vehicle engines and exhausts – shut them off, and keep hot exhausts away
• Electrical equipment and power tools – don’t switch them on, unless they are approved for use when there’s a fire risk
• Hot work (welding, grinding, cutting) – stop immediately
• Static electricity
• Smoking or open flames – extinguisher them

One of the first fire precautions during any spill is to identify and eliminate ignition sources where it is safe to do so.

Fire Precautions Before Clean-Up Begins

Before attempting any spill clean-up, responders should take these key precautions:

1. Assess the Substance

• Identify what has been spilled
• Check if it is flammable, combustible, or reactive
• Refer to safety data sheets (SDS) – if they are not in your workplace, look them up online.
• Treat unknown substances as hazardous.

2. Isolate the Area

• Keep non-essential people away
• Restrict access to the spill zone
• Pay special attention to low-lying areas where vapours may collect.

3. Control Ignition Sources

• Shut down vehicles and machinery if safe
• Prohibit smoking and naked flames
• Avoid switching electrical equipment on or off near the spill
• Use non-sparking tools where required.

4. Improve Ventilation

• Increase airflow to disperse vapours where possible
• Use natural ventilation before mechanical systems if an ignition risk exists, as turning on mechanical ventilation can cause a spark
• Never ventilate vapours into confined spaces.
• Be aware that heavier-than-air fumes are sometimes extremely difficult to ventilate naturally.

Spill Response Practices That Reduce Fire Risk

During clean-up, fire prevention remains a priority.

Good practice includes:

• Using the correct spill kit for the substance involved
• Containing the spill first with absorbent socks or booms
• Working from the outside of the spill toward the centre
• Avoiding actions that could generate sparks or heat
• Wearing appropriate PPE, including anti-static gear where required.

Absorbing the liquid alone does not eliminate fire risk, as vapours may still be present.

Handling and Disposal of Contaminated Materials

Used absorbents can remain flammable even after the liquid appears contained.

Fire precautions include:

• Placing used absorbents immediately into approved disposal bags or containers
• Sealing waste containers properly
• Storing waste away from ignition sources
• Labelling hazardous waste correctly
• Following site and regulatory disposal procedures.

Note that some materials can spontaneously combust in the right circumstances.

Never leave saturated absorbents exposed or piled loosely.

What to Do If Fire Risk Escalates

Spill responders should stop and withdraw if:

• Vapours become strong or overwhelming
• There are signs of ignition risk
• Anyone feels dizzy, unwell, or unsure
• The spill is larger than the spill kit’s capacity
• The substance is unknown or highly volatile.

In these situations:

• Evacuate the area
• Raise the alarm
• Contact emergency services or specialist response teams
• Do not attempt to fight fires unless trained and it is safe to do so.

Fire Response: If Ignition Occurs

If a spill ignites:

• Prioritise people over property
• Evacuate immediately
• Activate emergency procedures
• Only use fire extinguishers if trained, equipped, and it is safe
• Never re-enter an area until declared safe

Uncontrolled fire involving hazardous substances can escalate rapidly.

Training and Preparedness

Effective fire precautions during spill response rely on:

• Proper spill kit selection
• Regular inspection and maintenance of spill kits
• Clear emergency procedures
• Worker training and refresher sessions
• Understanding when not to respond

Spill response training is not just about clean-up — it is about risk control and decision-making under pressure.

To recap, if you have hazardous substances in your workplace, WorkSafe mandates that your team members complete dangerous goods handler, fire extinguisher and spill kit training. You can find all those courses in our hazardous substances training section.