Which fire extinguisher do I need?
Choosing the right fire extinguisher comes down to three things:
• what could catch fire
• where the risk is
• how large the space is
Get those right, and you’ll usually make the right choice.
Step 1 — Identify the fire risk
Ask yourself: what is most likely to catch fire?
Common risks include:
🔥 Flammable materials (Class A) — wood, paper, fabrics
⚡ Electrical equipment — appliances, sockets, machinery
🍳 Cooking oils and fats (Class F) — kitchens and food preparation areas
🛢 Flammable liquids or gases (Class B / C) — fuels and solvents
🧲 Flammable metals (Class D) — lithium, magnesium and other reactive metals (specialist risk)
Using the wrong extinguisher can make a fire worse, so identifying the risk correctly is essential.
Step 2 — Consider the environment
The same extinguisher is not suitable everywhere.
Typical environments include:
- Homes and flats
- Offices and retail spaces
- Workshops and plant areas
- Vehicles and boats
Who will be using the extinguisher, and how quickly it needs to be deployed, matters just as much as the fire risk itself.
Step 3 — Choose the right extinguisher type
Fire extinguishers are designed for specific risks:
- Water / Water Mist / Water Additive — primarily for Class A (flammable materials)
- Foam — suitable for Class A and flammable liquids (Class B)
- CO₂ — commonly used for electrical risks; limited cooling on Class A
- ABC Powder — suitable for Class A, flammable liquids (Class B) and flammable gases (Class C)
- Wet Chemical — designed for cooking oils and fats (Class F)
- Metal powder (Class D) — specialist extinguishers for flammable metals only
Each type has strengths and limitations. Choosing based on risk — not convenience — is key.
Step 4 — Match the size to the space
Bigger is not always better.
- Small spaces — compact, easy-to-handle units
- Medium spaces — standard portable extinguishers
- Large spaces — larger or multiple extinguishers
An extinguisher must be powerful enough to deal with a small fire, but still easy to use under pressure.
| Fire risk / class | Suitable extinguisher types | Avoid / notes |
|---|---|---|
| Flammable materials (Class A) | Water / Water Mist / Water Additive • Foam • ABC Powder | Avoid CO₂ as the only option (limited cooling / re-ignition risk) |
| Electrical equipment | CO₂ • Water Mist | Never use standard water on live electrics |
| Cooking oils and fats (Class F) | Wet Chemical | Avoid water and CO₂ on deep-fat fryer fires |
| Flammable liquids (Class B) | Foam • ABC Powder | Avoid water jets on burning liquids |
| Flammable gases (Class C) | ABC Powder | Priority is isolating the gas supply where safe |
| Flammable metals (Class D) | Class D metal powder extinguisher (specialist) | Do not use water/foam/CO₂/powder unless specifically rated for metals |
⚠ Common mistakes to avoid
- Choosing based on price instead of suitability
- Using one extinguisher type for all risks
- Selecting a unit that is too heavy to operate
- Ignoring electrical or cooking hazards
Final guidance
If you are unsure, it is safer to choose an extinguisher that covers multiple common fire risks, or to seek guidance based on your specific environment.
Understanding the risk, the space, and the extinguisher type helps ensure the right protection is in place — before it’s ever needed.