Understanding the Different Types of Fires
Did you know there are five different “classes” or categories of fire based on the substance that fuels them? Beyond that, there are different ways each fire should be put out, depending on its class.
If you’ve ever wondered whether the type of fire in your kitchen is the same as the one caused by faulty wiring, it’s not. Knowing the types of fire can help you react better in the event of a fire emergency.
No matter what kind of fire breaks out in your home, SERPRO offers fire damage restoration services to help get your house back to normal after the flames are extinguished.
Key Takeaways
- There are five types of fire classes, each defined by its fuel source: A, B, C, D, and K.
- Using the wrong extinguisher on certain fires can make the situation much worse.
- Every home should have the right type of fire extinguisher in key areas, such as the kitchen, garage, and laundry room.
- Knowing when to leave your home during a fire is just as important as knowing how to fight it.
- If a fire damages your home, SERVPRO is available 24/7 to handle the fire damage restoration process from start to finish.
The Five Classes of Fire
According to the Occupational Health and Safety Administration (OSHA), there are five classes of fire. Understanding each type of fire begins with learning what fuels it. The source of the fire determines how it behaves and how you should handle it.
| Fire Type | Source | What’s Burning | Where It Happens | How to Put It Out |
| Class A | Ordinary combustibles | Wood, paper, cloth, trash, some plastics | Homes, offices, warehouses | Water, foam, or dry chemical extinguisher |
| Class B | Flammable liquids/gases | Gasoline, propane, grease, oil | Garages, labs, industrial facilities | CO2, dry chemical, or foam extinguisher (never water) |
| Class C | Electrical equipment | Wiring, appliances, electrical components | Homes, commercial and industrial buildings | CO2 or dry chemical extinguisher (never water) |
| Class D | Combustible metals | Sodium, magnesium, aluminum | Chemical plants, factories, laboratories | Dry powder extinguisher specifically rated for Class D |
| Class K | Cooking oils and fats | Vegetable/animal oils, fats | Commercial and residential kitchens | Wet chemical extinguisher |
Class A Fires
Class A fires are a common type of fire that starts in a home. Think of a fireplace that gets out of hand, a trash can fire in the garage or burning leaves in the back yard. As OSHA notes, a good rule of thumb is that if a material leaves ash behind when it burns, it qualifies as a Class A fire.
Source Materials Include:
- Wood and lumber
- Paper and cardboard
- Cloth and upholstery
- Trash and yard debris
- Some plastics
How to Extinguish:
- Water
- Foam
- Dry chemical (ABC-rated) fire extinguisher
Where It Happens:
- Throughout the home
- Garages
- Attics
- Outdoor spaces
Class B Fires
Class B fires involve flammable liquids and gases, including gasoline, solvents, propane, and some oils and greases. These are the kinds of things you might store in your garage or shed without giving it too much thought. Fires can happen when a gas grill flares up or propane leaks near a heat source.
Unlike Class A fires, you don’t want to pour water on a Class B fire. The best way to put out a gas fire is to smother the flame.
Source Materials Include:
- Gasoline and diesel fuel
- Propane and natural gas
- Grease and oil
- Paint and solvents
- Lighter fluid
How to Extinguish:
- CO2
- Dry chemical or foam extinguisher
- Never use water! (It can spread the fire)
Where It Happens:
- Garages
- Kitchens
- Outdoor grilling areas
- Workshops
Class C Fires
Class C fires involve energized electrical components, and they’re more common in a home than many people realize. Faulty wiring, an overloaded outlet, a malfunctioning appliance, or an aging electrical panel can all start a Class C fire.
The most important thing to remember is that when electronics are involved in a fire, water’s not the answer. Water conducts electricity and can turn a small electrical fire into a much more dangerous situation.
Source Materials Include:
- Faulty or damaged wiring
- Electrical panels and circuit breakers
- Appliances and power tools
- Outlets and extension cords
- Lighting fixtures
How to Extinguish:
- CO2
- Dry chemical extinguisher only
- Never use water!
Where It Happens:
- Throughout the home
- Kitchens
- Laundry rooms
- Basements
- Utility areas
Class D Fires
Class D fires are caused by metal and/or flammable metallic materials like sodium, magnesium, or aluminum. While this type of fire is rare in residential settings, homeowners with workshops or hobby spaces for metalworking can be at risk.
Class D fires burn extremely hot and can be hard to control. If you experience a Class D fire, don’t reach for a standard fire extinguisher. Instead, always keep a fire extinguisher rated for Class D fires on hand if you work with metal at home.
Source Materials Include:
- Magnesium
- Sodium
- Aluminum shavings or powder
- Titanium
- Potassium
How to Extinguish:
- Dry powder extinguisher specifically rated for Class D fires
- Do not use a standard fire extinguisher
Where It Happens:
- Factories
- Chemical plants
- Laboratories
- Home metal fabrication workshops
Class K Fires
Of all the types of fires that can happen in the home, Class K fires are often the most common kitchen threat. Class K fires involve cooking oils and fats, and cooking is the leading cause of home fires in the U.S. For example, a pan of overheated oil or a deep fryer that gets too hot can escalate into a serious Class K fire in seconds.
Source Materials Include:
- Vegetable oils
- Animal fats
- Butter and lard
- Commercial frying oils
How to Extinguish:
- Wet chemical extinguisher
- Covering pan with lid
- Don’t use water
Where It Happens:
- Kitchens
How to Put Out Different Types of Fire
Because the different types of fire classes originate from different sources, they require different methods to be put out. For example, as noted above, water should not be used to extinguish Class C (or even Class B) fires, as this might cause electrical shock or the fire to spread even further.
Put the right types of fire extinguishers in key areas of your home, including the kitchen, garage, and laundry room.
If a fire flares up, take a beat to assess the situation. Ask yourself:
- Is the fire small and contained or is it growing?
- Is smoke filling the room?
- Do I know what’s burning and which extinguisher to use?
- Is my exit path clear?
Ultimately, when using a fire extinguisher, remember the acronym “PASS.”
“P” for Pull: Pull the fire extinguisher pin.
“A” for Aim: Use the nozzle to aim at the base of the fire.
“S” for Squeeze: Squeeze the trigger, allowing the product to release.
“S” for Sweep: With a sweeping motion, slowly move the nozzle from side to side.
Knowing when not to fight a fire is just as important as knowing how. If the fire is larger than a small wastebasket, if smoke’s blocking your exit, or you feel uncertain about the type of fire, don’t try to put it out yourself. Get everyone out of the house immediately, close doors behind you to slow the spread, and call 911 from a safe location.
For Any Type of Fire Damage Cleanup, SERVPRO is Here to Help
When there’s a fire in your home, it can be one of the most stressful and overwhelming events of your life. Whether it’s a kitchen grease fire or an electrical blaze, figuring out what to do afterward can feel daunting. That’s exactly where SERVPRO comes in.
SERVPRO is prepared to provide 24-hour emergency cleanup, restoration, and reconstruction services year-round to help return your property to pre-loss condition. Regardless of what type of fire affected your home, the fire damage restoration process typically involves the same key steps:
- Emergency board-up and roof tarping to secure your home
- Water removal if firefighting efforts caused water damage
- Smoke and soot removal from walls, ceilings, and surfaces
- Odor elimination using professional-grade deodorization equipment
- Contents cleaning and restoration, including furniture, documents, and personal belongings
- Reconstruction of any areas too damaged to restore
SERVPRO is the #1 choice in fire and water cleanup and restoration. We’ll handle every step of your fire damage restoration process with care, professionalism, and genuine understanding of what you’re going through. You don’t have to face this alone.
Find a SERVPRO location near you today.
FAQs
How many classes of fire are there?
There are five classes of fire, each defined by the material that fuels it. The five classes are:
- Class A
- Class B
- Class C
- Class D
- Class K
Knowing which class a fire belongs to is critical because using the wrong extinguisher can make certain fires worse and more dangerous.
What are the classes of fire?
The five types of fire are defined by their fuel source. Class A fires burn ordinary combustibles like wood and paper. Class B fires involve flammable liquids and gases. Class C fires involve electrical equipment. Class D fires involve combustible metals. Class K fires involve cooking oils and fats
Why does the type of fire matter?
The type of fire tells you how it should be extinguished. Using the wrong method, like spraying water on a grease fire or an electrical fire, can cause the fire to spread. Identifying the fuel source of a fire will help you respond the right way to protect your home and family.
How does the fire restoration process change for different types of fire?
The fire damage restoration process will vary depending on what burned in a home. Grease fires leave heavy residue that requires special degreasers. Electrical fires often cause hidden damage inside walls. Chemical and metal fires may involve hazardous materials that need special handling. SERVPRO can develop a tailored restoration plan for any type of fire in your home.