Fires involving solids. Liquids such as grease, fats, oil, paint, petrol,etc but not on domestic chip or fat pan fires. Can be used on class A fires but not recommended.

Less effective than AFFF foam

Check manufacturer's instructions for suitability of use on other fires involving liquids.

These extinguishers are generally not recommended for home use.

Do not aim jet straight into the liquid.

Where the liquid on fire is in a container, point the jet at the inside edge of the container or on a nearby surface above the burning liquid.

Allow the foam to build up and flow across the liquid.

These are mainly water based, with a foaming agent so that the foam can float on top of the burning liquid and break the interaction between the flames and the fuel surface.