What are the different types of fire extinguishers and their uses?
Portable fire extinguishers are classified by NFPA 10 according to the class of fire they can put out. Matching the extinguisher to the fire class is the core skill the exam tests.
| Fire class | Fuel | Extinguisher to use |
|---|---|---|
| Class A | Ordinary combustibles — wood, paper, fabric, most plastics | Water, foam, ABC dry chemical |
| Class B | Flammable liquids — gasoline, oil, grease, solvents | BC or ABC dry chemical, CO₂, foam |
| Class C | Energized electrical equipment | CO₂ or dry chemical (non-conductive) |
| Class D | Combustible metals — magnesium, titanium, sodium | Special dry powder only |
| Class K | Cooking oils and fats (commercial kitchens) | Wet chemical |
Common types used in Quebec:
- ABC dry chemical (5 lb to 20 lb): the most versatile (classes A, B and C). The powder is corrosive — the area must be cleaned after use.
- CO₂ (5 lb to 20 lb): for electrical and flammable-liquid hazards. Clean, leaves no residue.
- Water (2.5 gallons): Class A only. Never use it on an electrical fire.
Extinguisher prices vary by type, capacity (5 lb to 20 lb) and supplier.
Placement and inspection (NFPA 10):
- Travel distance: a maximum of 75 ft (22.9 m) to a Class A or Class D extinguisher, 30 to 50 ft for Class B depending on the hazard, and within 30 ft (9.1 m) of the cooking appliance for Class K. The distance is measured along the actual walking path, not a straight line.
- Inspection: a monthly visual inspection and annual maintenance by a certified technician.
Continue with the types of fire alarm and detection systems, the main NFPA standards applied in Quebec, or the fire safety technician preparation track (RBQ — Régie du bâtiment du Québec).
Questions similaires
How far apart must fire extinguishers be placed?
NFPA 10 caps the travel distance rather than the spacing: no more than 75 ft (22.9 m) to a Class A or Class D extinguisher, 30 to 50 ft for Class B depending on the hazard level and the extinguisher's rating, and within 30 ft (9.1 m) of the appliance for Class K. The distance is the actual walking path around walls and equipment, not the straight-line distance.
When is a Class K extinguisher required?
A Class K wet-chemical extinguisher is required in commercial kitchens, within 30 ft (9.1 m) of cooking appliances that use combustible cooking media such as deep fryers, griddles and woks. It supplements — it does not replace — the general ABC coverage of the room.