How to Read a Fire Extinguisher Label

Whether you're managing fire safety at a business or simply want to be prepared at home, knowing how to read a fire extinguisher label is essential. These labels contain critical information that can help you make quick, correct decisions in an emergency—and avoid using the wrong extinguisher on the wrong type of fire.

In this guide, we'll walk through what each part of a fire extinguisher label means, why it's important, and how to identify the extinguisher that’s right for your environment.

Why Fire Extinguisher Labels Matter

The label isn’t just there for show—it’s a safety guide. It tells you:

• What types of fires the extinguisher is rated for

• What extinguishing agent is inside

• How to use it properly

• Whether it’s certified and in service

For example, a CO₂ extinguisher should never be used on a fire involving combustible materials like paper or wood. Using the wrong extinguisher can be dangerous. To better understand fire classifications, the National Fire Protection Association (NFPA) offers a breakdown of fire types and extinguisher use.

Fire Classes You’ll See on the Label

Each label will display symbols or letters to indicate what fire classes the extinguisher is rated for:

• A – Ordinary combustibles (wood, paper, cloth)

• B – Flammable liquids (gasoline, oil, grease)

• C – Electrical equipment

• D – Combustible metals

• K – Cooking oils and fats (deep fryers, grills)

Most general-use extinguishers are ABC-rated. But CO₂ extinguishers, commonly found in commercial kitchens and tech-heavy spaces, are typically rated for B and C fires only. The Canadian Centre for Occupational Health and Safety (CCOHS) explains the differences and recommended usage.

Key Information Found on the Label

1. Class Rating

Usually printed at the top or front of the label as large letters (A, B, C, etc.) or icons. If the label says “ABC,” it can handle the three most common fire types.

2. UL/ULC Performance Rating

This rating shows how powerful the extinguisher is. For example:

• “3A:40B:C” means the extinguisher is equivalent to 3.75 gallons of water (3A)

• It can handle a 40-square-foot flammable liquid fire (40B)

• It's safe on electrical equipment (C)

Ratings are standardized by groups like Underwriters Laboratories of Canada (ULC), which certify equipment for safety in Canada.

3. Extinguishing Agent

The label will tell you what’s inside:

• CO₂ (Carbon Dioxide)

• Monoammonium Phosphate (Dry Chemical)

• Water Mist

• Wet Chemical (Class K fires)

For commercial kitchens, the Canadian Fire Code mandates the use of wet chemical extinguishers for grease fires.

4. Instructions for Use

Most labels include visuals of the PASS method:

• Pull the pin

• Aim at the base of the fire

• Squeeze the handle

• Sweep side to side

These visuals are designed to be understood in seconds, even in high-stress situations.

5. Inspection and Service Tags

You'll also see inspection dates, service history, and sometimes a tag for the last hydrostatic test. Pressurized cylinders like CO₂ extinguishers must be tested every 5 years. You can learn more about this process in our guide to hydrostatic testing.

Trusted Fire Protection in Ottawa

Reading a label is the first step—making sure your extinguisher is certified, maintained, and pressurized is just as important. At Rapid CO₂, based in Ottawa, Ontario, we specialize in:

• CO₂ fire extinguisher sales and service

• ABC dry chemical extinguisher sales and service

• Pressurized water and specialty extinguishers

We ensure every extinguisher is up to code, correctly labeled, and safe to use—whether it’s in a home, restaurant, warehouse, or office.

For service, testing, or fire protection support, call 613.299.8412.