Fire extinguisher types
Using the wrong fire extinguisher on the wrong fire can make the situation significantly worse — water on burning cooking oil causes an explosive fireball. This guide explains the six main extinguisher types, which fire classes each one tackles, and how to choose the right one for each part of your home or workplace.
Before you choose an extinguisher
Identify the fire class first. An ABC dry powder covers the most common household fire classes. A wet chemical extinguisher is essential in any kitchen with a deep fat fryer. Use our extinguisher finder tool to match fire type to the correct agent.
Extinguisher reference
Six main extinguisher types
Classes: Class A only
Use for: Effective on solid combustibles, low cost
Avoid: Never use on fat, electrical, or flammable liquid fires
Classes: Class A, Class B
Use for: Seals fuel surface, prevents re-ignition
Avoid: Messy. Not for fat fires or live electrical
Classes: Class B, Electrical
Use for: No residue, safe on electronics
Avoid: Short discharge time, re-ignition risk
Classes: Class A, B, C (US); A, B, electrical (UK)
Use for: Broadest coverage, effective on gas fires
Avoid: Poor visibility, lung irritant, leaves residue
Classes: Class K (US) / Class F (EN)
Use for: Only agent rated for deep fat fryer fires
Avoid: Not suitable for Class A or B without a dual rating
Classes: Class A, B, electrical (de-ionised)
Use for: Safe on live electrics, no residue, no toxic fumes
Avoid: Higher cost, not for fat fires unless dual-rated
Why wrong agent choice can be catastrophic
Water on burning cooking oil causes a steam explosion — the water instantly vaporises, expanding to approximately 1,700 times its liquid volume, throwing burning oil across the room. CO2 on a smouldering Class A fire may temporarily suppress flames but not extinguish the deep-seated combustion. Dry powder on a Class D (combustible metal) fire can react violently with some metals. Understanding what you are dealing with before reaching for an extinguisher is the most important step. If in doubt, evacuate. See our fight-or-flee decision guide for when to use an extinguisher at all.
Colour coding — UK vs US
UK extinguishers all have red bodies with a coloured panel or label identifying the type (cream = foam, black = CO2, blue = dry powder, yellow = wet chemical, white = water mist). US extinguishers are more varied in colour — relying primarily on text labelling under NFPA 10. Do not rely on colour alone when selecting an extinguisher in an unfamiliar location — always read the label. For a full comparison of fire class letter systems in the US and UK, see our fire classes glossary.
Place extinguishers on the exit route
Position extinguishers on the way out — not between you and the fire. In a kitchen, mount the extinguisher near the door, not above the hob. This means you can grab it as you pass and still have a clear retreat route if the fire grows.
PASS — using any extinguisher correctly
Regardless of type, all portable extinguishers are operated using the PASS technique: Pull the safety pin, Aim at the base of the fire, Squeeze the handle, Sweep from side to side. Start at the maximum effective range shown on the label. Discharge time for a 1–2 kg unit is typically 8–12 seconds — if the fire is not out when the agent runs out, evacuate immediately. Full technique guidance is in our fight-or-flee guide.
Sources: NFPA 10 · BS EN 3 · BS 5306-3 · UK HSE fire safety guidance
Extinguisher types FAQ
Questions about fire extinguisher types
For most homes, a 2 kg or 1 kg ABC dry powder extinguisher provides the broadest coverage across ordinary combustibles (Class A), flammable liquids (Class B), and energised electrical equipment (Class C in the US, not a formal EN class in the UK). For kitchens, add a wet chemical (Class K/F) extinguisher or a fire blanket for cooking oil fires — water and foam must never be used on burning fat. The NFPA extinguisher guidance recommends at least one extinguisher per floor, in an accessible location. Use our extinguisher finder tool to confirm the right type for your situation.
CO2 extinguishers work by displacing oxygen, leaving no residue — ideal for electrical equipment (server rooms, labs, offices) and flammable liquids. They cool poorly and re-ignition is possible once the gas disperses. Dry powder extinguishers interrupt the chemical chain reaction and smother the fire; they are effective on a wider range of fire classes but leave a fine powder that is difficult to clean and can obscure vision. Dry powder should not be used indoors in occupied spaces if avoidable — the powder irritates lungs. For electrical fires, CO2 is preferred where visibility and clean-up matter.
No — never use a water extinguisher on live electrical equipment. Water conducts electricity, creating a risk of electrocution. If you need to tackle an electrical fire, first isolate the power if safe to do so, then use a CO2 or dry powder extinguisher. If the power cannot be isolated, CO2 is the safest agent. Modern mist extinguishers (water mist) use de-ionised water that is safe on electrical equipment up to 35 kV — they carry a dielectric test certificate. Standard water extinguishers do not. See the fire classes glossary for the full class/extinguisher matrix.
All UK extinguishers have a red body. The label colour and panel identify the type: water (red label), foam (cream), CO2 (black), dry powder (blue), wet chemical (yellow), and water mist (white). US extinguishers use a similar colour convention but the labelling requirements differ under NFPA 10. Always read the label on the extinguisher to confirm its class rating before using it on a fire.
Most portable extinguishers have a service life of 5–12 years depending on type and manufacturer. Annual inspection by a qualified technician is required under NFPA 10 and UK BS 5306-3. A 6-year internal examination is required for dry chemical units. Once an extinguisher has been used — even partially — it must be recharged or replaced before being returned to service. See our fire extinguisher maintenance guide for the full inspection schedule.