Dry Powder Fire Extinguishers

A dry powder extinguisher is operated by directing pressurised powder at the base of a fire. Depending on the model, pressure is either stored within the cylinder or supplied by a separate gas cartridge on activation. The fast-moving cloud reaches fire quickly across a wide area, which explains both its versatility across fire classes and the visibility reduction it causes indoors.

Dry powder extinguishers are one of the few types rated for Class C flammable gas fires, alongside Class A and Class B. This makes them particularly valuable where LPG, natural gas or other combustible gases are present. Check the classification label on your extinguisher before use, as ratings vary between models. 

Dry powder extinguishers are used in high-risk commercial and industrial environments where multiple fire classes may be present simultaneously. Construction sites, vehicle workshops and industrial premises are among the most common settings. They are also widely fitted to vehicles, plant machinery and fuel storage areas where the risk of Class B or C fire is highest.

Inverting the cylinder of a powder extinguisher is part of the service procedure for cartridge operated powder extinguishers and isn’t required for stored pressure powder extinguishers by the British Standard BS 5306-3:2009. However it is good practice to perform this action during a basic service on stored pressure extinguishers as it only takes a moment and ensures that the contents are not compacted.

HGVs carrying dangerous goods require dry powder fire extinguishers and must comply with The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations (CDG) where the minimum amount of dry powder depends on the vehicle tonnage. To find out the requirements for your vehicle, please see the summary of minimum dry powder requirements.

Powder fire extinguishers are not banned as they are not toxic, but they are mainly recommended for outdoor use, due to the possibility of reduced visibility and a risk of inhalation when used indoors.

An ‘ABC’ Powder Fire Extinguisher (or dry powder fire extinguisher), often referred to as general or multi-purpose, is designed to tackle Class A, B and C fires. This type of extinguisher typically use ammonium or a mono-ammonium phosphate mixed with other powders and works by smothering the fire, to starve it of oxygen. Dry powder extinguishers can be used in a number of locations but are most often found at petrol forecourts, in vehicles and garages, or where fire involving flammable liquids and gases could be a hazard. Whilst these extinguishers are versatile, being suitable for use on most common fire types, their use indoors is not encouraged due to the mess powder creates and the potential impairment of vision and effects on respiration it can cause.

You can use a dry powder fire extinguisher indoors, but it's not recommended for most indoor spaces. The powder spreads quickly, reducing visibility and making it harder to escape. It can also cause respiratory problems and stomach irritation if inhaled. However, they're suitable for some indoor areas, such as boiler rooms, garages, and specific warehouses, where the benefits outweigh the risks.

Dry powder extinguishers work effectively outdoors because they won't freeze, unlike water-based extinguishers. They're perfect for garage forecourts, open workshops, goods yards, and vehicles. The powder spreads effectively in open areas without creating the visibility and breathing problems you'd get in enclosed spaces. Plus, there's better ventilation outdoors to disperse the powder after use.

For vans and smaller commercial vehicles, a 1kg or 2kg dry powder extinguisher works well. Lorry cabs typically need a 2kg extinguisher, but larger commercial trucks often carry 6kg extinguishers. The slimline powder extinguishers with transport brackets are ideal for vehicles as they fit neatly and securely. Check your vehicle's specific requirements, as some industries have particular standards.

Traditional dry powder extinguishers need annual servicing by a qualified technician. However, some models, like P50 Service-Free Fire Extinguishers, don't require yearly company servicing, which reduces your maintenance costs.

Cleaning up powder residue takes patience but isn't complicated. Sweep or vacuum up the bulk of the powder first, then wipe surfaces with a damp cloth. Don't use water immediately as it can create a paste. The powder is non-toxic but can irritate the skin and eyes; therefore, wear gloves and avoid inhaling dust. Soft furnishings are challenging to clean, which is why powder extinguishers are better suited for hard-surfaced areas.