There are just two types of dry powder fire extinguishers available: standard and specialist. Standard dry powder extinguishers can extinguish almost any type of fire. Specialist dry powder extinguishers are for certain types of metal fires. However, because of the dispersal of powder, it’s important not to use them in enclosed spaces.
Dry powder extinguishers can also be known as ABC extinguishers, multi-purpose extinguishers or dry chemical extinguishers.
Standard dry powder extinguishers can be used on:
- Class A fires – combustible materials: caused by flammable solids, such as wood, paper, and textiles
- Class B fires – flammable liquids: such as petrol, paint or spirits
- Class C fires – flammable gases: like propane and butane
- Electrical fires – electrical equipment: such as computers and photocopiers
Specialist dry powder extinguishers can be used on:
- Flammable metal fires: such as lithium (L2 powder extinguishers only)
- All other flammable metal fires: (M28 powder extinguishers only)
Dry powder extinguishers should never be used on the following fire types:
- Class F fires – cooking oils: such as olive oil or butter. Typically a chip-pan fire
- Electrical fires: if the voltage exceeds 1000v
- Flammable metal fires: unless it’s a specialist dry powder extinguisher
Identifying a Dry Powder Fire Extinguisher
Dry powder fire extinguishers have a blue coloured label stating ‘DRY POWDER’. It should also have a sign above or next to the extinguisher that states ‘Powder Extinguisher’.
Dry powder extinguishers come in foam sizes:
- 1 kg
- 2 kg
- 3 kg
- 6 kg
- 9 kg
How Dry Powder Fire Extinguishers Work
These extinguishers work by smothering a fire and creating a barrier between the source of the fire and oxygen. However, because there’s no cooling effect with a dry powder extinguisher, there’s a small change of the fire re-igniting.
When to choose a Dry Powder Fire Extinguisher
They’re suited to open or outdoor environments where there’s a fire risk from several different sources. An example would be a garage forecourt or a workshop, where there’s a fire risk present from fuel, vehicles, and chemicals.