Key Takeaways
- Fire extinguishers are classified by fire type: A, B, C, D, and K.
- Fire extinguishers also have a numerical rating that indicates their extinguishing potential.
- The higher the number, the larger the fire they can put out.
- You should choose a fire extinguisher that matches the type and size of fire you may encounter.
- You can also look for multipurpose fire extinguishers that can handle more than one fire type.
What are Fire Extinguisher Ratings?
Fire extinguisher ratings are a way of indicating the type and size of fire that a fire extinguisher can put out. They are based on standardized tests conducted by the Underwriters Laboratory (UL), a safety certification organization.
Fire extinguisher ratings consist of a letter and a number. The letter corresponds to the class of fire that the fire extinguisher can handle, while the number indicates the amount of fire that it can extinguish.
There are five classes of fire, each with different characteristics and fuel sources:
| Class | Description | Examples |
|---|---|---|
| A | Fires in ordinary combustible materials, such as wood, paper, cloth, rubber, and plastics. | Trash cans, furniture, curtains, books. |
| B | Fires in flammable liquids and gases, such as gasoline, oil, grease, acetone, propane, and butane. | Gas stoves, paint cans, barbecue grills, cars. |
| C | Fires involving energized electrical equipment, such as appliances, wiring, outlets, and circuit breakers. | Computers, TVs, microwaves, fuse boxes. |
| D | Fires in combustible metals, such as magnesium, titanium, sodium, potassium, and lithium. | Metal shavings, powders, flakes. |
| K | Fires in cooking oils and fats, such as vegetable oil, animal fat, and grease. | Deep fryers, frying pans, pots. |
The numerical rating for a class A fire extinguisher is based on the equivalent amount of water that it contains. For example, a 2-A fire extinguisher has the same extinguishing potential as 2.5 gallons of water (2 x 1.25). The higher the number, the larger the fire it can put out.
The numerical rating for a class B fire extinguisher is based on the area of fire that it can cover in square feet. For example, a 10-B fire extinguisher can cover 10 square feet of fire. The higher the number, the larger the fire it can put out.
Class C fire extinguishers do not have a numerical rating because they are designed to be used on electrical fires only. They contain non-conductive agents that will not cause electric shocks or damage to electrical equipment.
Class D and K fire extinguishers also do not have a numerical rating because they are designed to be used on specific types of fires only. They contain special agents that can smother and cool down the burning metals or oils.
How to Choose a Fire Extinguisher Based on Ratings
When choosing a fire extinguisher for your home or business, you should consider the following factors:
- The type of fire that you may encounter
- The size of the area that you need to protect
- The ease of use and maintenance of the fire extinguisher
You should choose a fire extinguisher that matches the type of fire that you may encounter in your location. For example, if you have a kitchen with a gas stove and a deep fryer, you should have a class B and K fire extinguisher nearby. If you have a garage with flammable liquids and electrical equipment, you should have a class B and C fire extinguisher nearby.
You should also choose a fire extinguisher that has enough capacity to handle the size of the fire that you may encounter. For example, if you have a large warehouse with combustible materials stored in it, you should have a high-rated class A fire extinguisher nearby. If you have a small office with computers and appliances in it, you may only need a low-rated class C fire extinguisher nearby.
You should also choose a fire extinguisher that is easy to use and maintain. You should look for features such as:
- A clear label with instructions and ratings
- A pressure gauge that shows if the fire extinguisher is ready to use
- A pin and seal that prevent accidental discharge
- A handle and nozzle that are easy to grip and aim
- A lightweight and portable design
- A rechargeable or disposable option
Multipurpose Fire Extinguishers
Some fire extinguishers are designed to handle more than one type of fire. These are called multipurpose or combination fire extinguishers. They have more than one letter in their rating to indicate their versatility.
For example, a fire extinguisher with a rating of 2-A:10-B:C can be used on class A, B, and C fires. It has the same extinguishing potential as 2.5 gallons of water for class A fires, 10 square feet of fire for class B fires, and non-conductive agents for class C fires.
Multipurpose fire extinguishers are convenient and cost-effective because they can be used in different situations. However, they may not be as effective as specialized fire extinguishers for certain types of fires. For example, a multipurpose fire extinguisher may not be able to put out a large or deep-seated class K fire as well as a dedicated class K fire extinguisher.
Therefore, you should always check the ratings and instructions of the fire extinguisher before using it. You should also follow the safety guidelines and best practices for using and storing fire extinguishers.
Conclusion
Fire extinguisher ratings are a way of indicating the type and size of fire that a fire extinguisher can put out. They are based on standardized tests conducted by the Underwriters Laboratory (UL).
Fire extinguisher ratings consist of a letter and a number. The letter corresponds to the class of fire that the fire extinguisher can handle, while the number indicates the amount of fire that it can extinguish.
You should choose a fire extinguisher that matches the type and size of fire that you may encounter in your location. You should also look for features that make the fire extinguisher easy to use and maintain.
You can also opt for multipurpose fire extinguishers that can handle more than one type of fire. However, you should always check the ratings and instructions of the fire extinguisher before using it.
By choosing the right fire extinguisher based on ratings, you can protect yourself and your property from fire hazards.
