| Class | What Burns | Correct Extinguisher |
|---|---|---|
| A | Solids: wood, paper, fabrics | Foam, powder, CO₂, water |
| B | Liquids: gasoline, alcohol, solvents | Foam, CO₂, powder (never water) |
| C | Gases: methane, LPG | Powder, CO₂ (close gas first) |
| F | Cooking oils and fats | Specific foam (never water, never powder) |
Have you seen the letters A, B, C, F on a fire extinguisher and wondered what they mean? Knowing fire classes is essential for choosing the right device — and, above all, for using it correctly in an emergency.
What are fire classes?
Fire classes are a standardized European classification (standard EN 2) that divides fires based on the type of material that is burning. Each class requires a specific extinguishing agent: using the wrong type may not work — or may worsen the situation.
Class A — Solid Materials
What burns: wood, paper, cardboard, fabrics, plastic, rubber
Where it's found at home: everywhere — furniture, curtains, clothes, books, coverings
How to extinguish it: water, foam, powder, CO₂. Most domestic extinguishers cover Class A.
Recognition: embers and slow flames that continue to burn even after initial intervention — solid materials can reignite if not completely extinguished.
Class B — Flammable Liquids
What burns: gasoline, diesel, alcohol, solvents, paints, acetone
Where it's found at home: garage (gasoline, solvents), workshop, basement, car box
How to extinguish it: foam, CO₂, powder. Never use water on a Class B fire: water causes the flammable liquid to splash, spreading the flames.
Main danger: flames spread rapidly along the surface of the liquid. Only intervene if the fire is small and you have a clear escape route.
Class C — Flammable Gases
What burns: methane, LPG, butane, propane
Where it's found at home: kitchen (mains gas), gas heating, camping gas cylinders
How to extinguish it: the main rule for Class C is to first shut off the gas at the source, then extinguish any residual flames with powder or CO₂.
Warning: if you cannot shut off the gas, evacuate immediately and call the Fire Brigade (115). Do not attempt to extinguish a continuously fueled gas fire.
Class D — Flammable Metals
What burns: magnesium, sodium, powdered aluminum, lithium
Context: industrial environments, laboratories, specialized workshops — not relevant for normal domestic use.
Class D extinguishers are highly specialized. Dexty is not designed for this class — and you don't need it at home.
Class F — Cooking Fats and Oils (the most dangerous at home)
What burns: vegetable oils, animal fats, lard — at high frying temperatures (>250°C)
Where it's found at home: kitchen, during frying in a pan or deep fryer
How to extinguish it: only agents certified for Class F, such as Dexty V1.0 foam.
Why it's dangerous: frying oil starts burning spontaneously at about 320°C. Never use water: contact of water with boiling oil causes a steam explosion that projects incandescent oil up to 3–5 meters — one of the most dangerous situations in a domestic fire.
Electrical Fires: not a class, but requires special attention
Fires from electrical systems do not have their own EN 2 class, but require an extinguisher tested and certified for use on live equipment. Using water on a live electrical appliance carries a risk of electrocution.
Dexty V1.0 is tested and approved for use on electrical systems up to 1000V — crucial in a modern home where outlets, appliances, and systems are everywhere.
Why Dexty covers the classes that matter at home
Dexty V1.0 is certified for classes A, B, C, and F — the four statistically most frequent classes in Italian domestic environments — and is safe on electrical systems up to 1000V.
With a single device, you can tackle:
- Kitchen fires (Class F + A)
- Solvent or gasoline fires in the garage (Class B)
- Gas leaks (Class C)
- Short circuits and electrical outlets (1000V certified)
How to read an extinguisher label
- Class letters (A, B, C, F) — must be present on the label
- Number before the letter (e.g., 21A, 113B) — indicates the tested extinguishing capacity. The higher the number, the greater the effectiveness
- CE marking — mandatory for sale in Europe
- PED compliance (Pressure Equipment Directive) — for pressure devices
Frequently Asked Questions
Can I use a Class A extinguisher on a kitchen oil fire?
No. Frying oil is Class F and requires specific agents. A Class A-only extinguisher could be ineffective or harmful. Always choose a device with Class F for the kitchen.
Does Dexty work on gas fires?
Yes, Dexty is certified for Class C. Remember to first shut off the gas supply, then intervene with the extinguisher on any residual flames.
What happens if I use water on a Class F fire?
Water in contact with boiling oil generates a violent steam explosion that can project incandescent oil several meters. It is one of the most dangerous situations you can create in a kitchen.
Does a powder extinguisher cover Class F?
No. ABC powder is not certified for Class F. On burning frying oil, the powder jet can cause explosive projections. For the kitchen, an F-certified foam extinguisher is always needed.
How many classes should a domestic extinguisher cover?
Ideally A, B, C, and F — plus certification for electrical systems. This is exactly the profile of Dexty V1.0.
