Types of Fire Extinguishers: Fire Classes A, B, C, D & K Explained
Every fire extinguisher is rated for specific types of fire, and using the wrong one can make a fire worse or put you in danger. The National Fire Protection Association (NFPA) sorts fires into five classes based on what's burning: Class A (ordinary combustibles like wood and paper), Class B (flammable liquids like gasoline and oil), Class C (energized electrical equipment), Class D (combustible metals), and Class K (cooking oils and fats). This guide breaks down what each class actually means for your home, and which type of extinguisher covers which fires.
The 5 Fire Extinguisher Classes
| Class | Fuel Type | Common Home Examples |
|---|---|---|
| A | Ordinary combustibles | Wood, paper, cardboard, most household trash, upholstery |
| B | Flammable liquids and gases | Gasoline, propane, paint thinner, cooking oil spills, solvents |
| C | Energized electrical equipment | Wiring, breaker panels, appliances, power tools while plugged in |
| D | Combustible metals | Rare in homes; workshop metal shavings (magnesium, titanium) |
| K | Cooking oils and fats | Deep fryers, grease fires in kitchens |
Cooking fires cause roughly half of all reported home fires, according to NFPA data, which is why Class K/B coverage in the kitchen matters even though home kitchens aren't legally required to have a dedicated Class K unit the way commercial kitchens are.
Which Extinguisher for Which Fire? Quick Lookup
- Electrical fire (outlet, wiring, appliance while plugged in): Use a Class C-rated extinguisher (most ABC units are rated for this). Never use a water or water-mist extinguisher: water conducts electricity and creates a shock hazard.
- Grease or cooking oil fire: Never use water. Smother a small pan fire with a metal lid and turn off the heat. For a fire too large to smother, use a Class K or Class B-rated extinguisher, ideally from outside the danger zone.
- Wood, paper, or fabric fire: Any Class A-rated extinguisher, including water, foam, or ABC dry chemical.
- Flammable liquid fire (gasoline, solvents, paint thinner): Use a Class B-rated extinguisher (foam, CO2, or ABC dry chemical). Never use a straight water stream: it can spread burning liquid.
- Garage or workshop metal fire (rare): Requires a specialized Class D extinguisher; standard ABC units are not rated for this and shouldn't be used.
- Electronics you don't want to coat in powder residue: A CO2 extinguisher leaves no residue and is Class B/C rated, making it a common choice near computers, servers, or a home office.
Why ABC Dry Chemical Is the Standard Home Choice
An ABC dry chemical extinguisher is rated for Class A, B, and C fires in one unit, which is why it's the extinguisher recommended by the U.S. Fire Administration for most home locations: it covers ordinary combustibles, flammable liquids, and electrical fires without you needing to identify the exact fire type in the first panicked seconds. The tradeoff is that dry chemical powder is corrosive to electronics and leaves a mess that requires cleanup, and it is not appropriate for a Class D metal fire.
Top Picks: Which Extinguisher Should You Buy
Once you know your fire class, the actual buying decision usually comes down to size and location. These are starting points; see our full guides for the complete comparison and reasoning behind each pick.
Kidde Pro 210 (ABC, 4 lb) — Best for Kitchen/Hallway
A rechargeable ABC dry chemical unit light enough to mount near an exit without feeling like a burden to grab quickly. Full sizing-by-room breakdown in our best fire extinguisher for home guide.
Check Price on Amazon ↗Kidde Pro 10 (ABC, 10 lb) — Best for Garage/Workshop
A larger unit with meaningfully more flammable-liquid coverage for a space with fuel, solvents, or power tools. Details in the same home buying guide.
Check Price on Amazon ↗Fire Blanket — Best First Response for Grease Fires
Smothers a stovetop grease fire without the mess or electronics-corrosion risk of dry chemical powder. See our dedicated best kitchen fire extinguisher guide, including Class K picks for frequent deep-fryer use.
Check Price on Amazon ↗What NOT to Use on Each Fire Type
- Never use water on an electrical fire: water conducts electricity and can electrocute you.
- Never use water on a grease or oil fire: per NFPA guidance, water sinks below the burning oil, flash-boils, and can violently eject burning oil out of the pan.
- Never use an ABC dry chemical extinguisher on a Class D metal fire: the chemical reaction can intensify the fire. Class D fires need a specialized dry powder agent.
- Never fight a fire that's already spreading beyond its point of origin, blocking your exit, or producing heavy smoke: leave immediately and call 911. Extinguishers are for small, contained, early-stage fires only.
Placement and NFPA 10 Mounting Distances
NFPA 10 sets maximum travel distances so an extinguisher is always within reach: generally no more than 75 feet to a Class A-rated extinguisher and 30-50 feet to a Class B-rated unit, depending on its rating. In practical home terms, that means one extinguisher per level of your home at minimum, mounted on a wall near an exit (not tucked behind a door or under the sink where a fire could block access to it), and never so hard to reach that grabbing it takes longer than leaving the room would.
Fire Extinguisher Types FAQ
What type of fire extinguisher do I need for an electrical fire?
Use a Class C-rated extinguisher. Most multipurpose ABC dry chemical extinguishers are rated for Class C, so a standard home ABC unit works. Never use water or a water-mist extinguisher on an electrical fire, since water conducts electricity and creates a serious shock hazard.
What's the best fire extinguisher for a grease or cooking oil fire?
For a small pan fire, smother it with a metal lid and turn off the heat rather than reaching for an extinguisher at all: this is the NFPA's own recommended first response. For a larger fire, use a Class K (commercial kitchens) or Class B-rated extinguisher. Never use water on a grease fire; it can cause the burning oil to erupt violently.
What are the 3 (or 4, or 5) most common types of fire extinguishers?
By fire class there are five: A (ordinary combustibles), B (flammable liquids), C (electrical), D (combustible metals), and K (cooking oils). By product type, the three most commonly sold for home and light-commercial use are ABC dry chemical (covers A, B, and C in one unit), CO2 (clean-agent, no residue, rated for B and C), and Class K wet chemical (commercial kitchens). For a home, an ABC unit covers nearly every realistic scenario.
What type of extinguisher is suitable for flammable liquids?
A Class B-rated extinguisher, which includes foam, CO2, and ABC dry chemical units. Never use a straight water stream on a flammable liquid fire (like gasoline): it can spread the burning liquid rather than putting it out.
Do I need a Class K fire extinguisher at home?
Not legally: Class K extinguishers are a requirement for commercial kitchens, not homes. A standard ABC extinguisher handles most home kitchen fires. That said, if you deep-fry regularly or cook with large quantities of hot oil, a dedicated Class K or Class B unit adds a real layer of protection beyond what an ABC unit's rating covers for oil fires specifically.