# Fire extinguisher classes and types: A, B, C, D and K

Match the hazard to the label and avoid treating an ABC extinguisher as suitable for every fire.

Updated 2026-11-10. Also on the [web page](https://extinguishers.fyi/guides/extinguisher-classes-and-types).

Start with the fuel or equipment involved. CCOHS defines the following fire classes [source below]. These definitions help you ask for the correct equipment. They do not tell you that it is safe to fight a particular fire.

| Class | Hazard in the CCOHS definition |
| --- | --- |
| A | Ordinary combustibles, such as paper, wood, cloth, rubber or plastics. |
| B | Flammable liquids, gases, oil, paints or lacquer. |
| C | Energized electrical equipment. |
| D | Combustible metals, such as magnesium or titanium. |
| K | Cooking oils or fats in cooking appliances. |

## Agent and class are different

CCOHS describes water units for Class A, carbon dioxide units for B and C, dry chemical units with the classes shown on their labels, and wet chemical units for K [CCOHS]. Read the actual label. Do not infer a rating from cylinder colour or appearance.

For combustible metals, CCOHS says to use a Class D extinguisher compatible with the metals present. Tell the supplier which metals and processes are involved. A general dry chemical extinguisher is not a substitute for that assessment.

## Keep water away from incompatible hazards

CCOHS warns against water on energized electrical equipment, flammable liquids and cooking oil fires [CCOHS]. When asking for equipment, describe the hazard rather than asking for the cheapest cylinder.

## Prepare people as well as equipment

Give the contractor a list of work areas, fuels and cooking processes. Ask for labels and training that staff can understand. CCOHS advises evacuation and calling the fire department if you lack the correct equipment or are not confident you can act safely. Do not use this guide or the class selector during an emergency.

## Sources

- [CCOHS, Fire Extinguishers: Portable](https://www.ccohs.ca/oshanswers/safety_haz/fire_extinguishers.html), fetched 2026-11-10.

Checked 2026-11-10. Planning information only. Confirm the adopted code, equipment instructions and local requirements with your fire authority.

## Questions

### Does ABC cover cooking oil and metal hazards?

The CCOHS definitions identify K and D separately. Ask a qualified supplier for equipment suited to those hazards.