How to Use a Foam Extinguisher

Foam fire extinguishers are suitable for use on class A and class B fires but but are used in different ways depending on the type of fire they are being used on. Please note that foam extinguishers should only be used on or near live electrical equipment if they are di-electrically tested.

Only tackle small fires with an extinguisher. If the fire has taken hold do not fight the fire but evacuate immediately and warn others of the fire, then call the fire and rescue service. If you tackle the fire make sure you stay at a safe distance and follow the instructions below.

1. Pull the safety pin (Fig.3), this will also break the tamper seal
2. Squeeze the lever to start discharging the extinguisher.
3. Where to aim the fire extinguisher nozzle:
   • Flammable liquids: Aim the hose at a vertical surface near the fire, do not spray directly at the fire as this could cause the burning liquid to splash and the fire to spread to surrounding areas. Foam extinguishers build up of foam on the surface of the burning liquid, cutting off the oxygen supply to the fire and cooling the hot liquid.
   • Electrical fires: If your foam extinguisher is tested to 35000 Volt (35kV) you can use the extinguishers on live electrical fires. However, keep a safety distance of 1m.
   • Solid combustibles: Aim the nozzle at the base of the fire, moving across the area of the fire
4. Ensure all of the fire has been extinguished; the foam creates a blanket over the fire and helps to prevent re-ignition.

Reviewed: 20/12/2019 (doc:17 V2.0). Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.