With fire safety very much in the news following a major fire in Glasgow city centre, questions are being asked about the risks of electrical fires and lithium-ion battery fires. While electrical fires have long been well-understood and managed, the rapid growth of lithium-ion battery powered devices is changing that landscape. Modern workplaces now contain large numbers of rechargeable batteries, from tools and laptops to e-bikes and vaping devices. UK fire services report a steady increase in incidents involving rechargeable batteries, you can read this article from the SFRS which highlights the need to understand how these fires differ from conventional electrical fires.

The distinction matters because the effectiveness of fire extinguishers depends entirely on the fire chemistry involved. All fires need three elements to burn: Heat, Fuel and Oxygen, often referred to as the Fire Triangle. If you remove any of these the fire goes out, fire extinguishers are designed to interrupt at least one side of this triangle.

Electrical Fires:

Electrical fires usually begin when electrical energy is converted into heat where it should not be. This can happen through damaged wiring, overloaded sockets, loose connections or failing equipment. As resistance increases, components heat up. If nearby materials such as plastic insulation, dust or furnishings reach ignition temperature, a fire starts. It’s important to note that electricity itself does not burn, the heated surrounding combustibles burn. The presence of live electricity simply adds an additional hazard, increasing the risk of electric shock during firefighting.

• CO₂ extinguishers release carbon dioxide gas stored under pressure, when discharged the gas rapidly expands into a cold cloud that surrounds the fire. This cools the fire slightly and displaces the oxygen to starve the fire. It’s non-conductive so avoids the risk of electric shock.
• Dry Powder extinguishers release powder which interferes with the chemical reactions taking place within the flame. It forms a barrier between the fuel and oxygen and provides rapid flame knock-down. The powder is non-conductive, however it’s recommended that it’s not used indoors as the fine powder can obscure vision, affect breathing, and contaminate equipment.

Lithium-Ion Battery Fires:

Rather than external fuel burning that happens in other fires, a failure within a lithium-ion battery can trigger “thermal runaway”, a self-accelerating chemical reaction caused by internal damage, overheating or charging faults. Thermal runaway occurs when internal battery components break down and release flammable gases, creating rapid heat generation and ignition. Even once the flames are gone, the fire may reignite – sometimes hours after seeming to be extinguished. You can read further on the topic via this link from the British Safety Council.

Official advice is to not attempt to tackle a lithium battery fire by yourself, on discovering a battery fire the advice is to evacuate immediately, close any doors between you and the fire, and dial 999.

While the HSE does not prescribe specific extinguisher types for every scenario, its guidance reinforces that extinguishers must be suitable for identified risks, accessible, properly maintained, and supported by training and risk assessment. Extinguisher provision must align with the fire risk assessment and foreseeable hazards, and for many workplaces lithium battery charging is now a foreseeable risk.

So, what do we recommend? A comprehensive Fire Risk Assessment is the first step, followed by actioning any controls and measures identified.

For electrical risks, organisations should consider:

• Training staff to identify early warning signs
• Implementing Portable Appliance Testing (PAT)
• Conducting EICR for the premises
• Remove block adaptors and extension reels
• If extension reels must be used, ensuring they’re not overloaded (daisy chained)
• Removing damaged appliances and cables from service

For lithium-ion battery risks organisations should focus on prevention, not firefighting.

• Designating safe charging and storage areas
• Keeping batteries away from escape routes
• Installing detection and alarms
• Developing evacuation-first procedures