When it’s time to purchase fire extinguishers for your business, you may be confused by the different letters and numbers on the label. To ensure you buy the right type and size for the application you have in mind, learn more about fire extinguisher classes and size ratings.
Fire Extinguisher Classes
The letter on a fire extinguisher indicates its classification:
- Class A puts out ordinary combustible fires (wood, paper, plastic, etc.)
- Class B puts out flammable liquid fires (oil, gas, petroleum, etc.)
- Class C puts out electrical fires
- Class D puts out combustible metal fires (magnesium, titanium, potassium, sodium, etc.)
- Class K puts out cooking fires ignited by flammable oil and grease
Since Class A, B, and C fires are all found in conventional homes and businesses, ABC fire extinguishers are designed to put out all three types of fires.
Fire Extinguisher Size Ratings
You might come across a fire extinguisher labeled 4A:20B:C. The numbers indicate the size rating of each extinguishing agent. Here’s how it works:
- The Class A size rating represents the water equivalency. Each number represents 1 ¼ gallons of water. For instance, 2A means the extinguisher is just as effective as 2 ½ gallons of water. 4A is equivalent to 5 gallons of water.
- The Class B size rating indicates the square footage the extinguisher can cover. 20B means that as long as you sweep the nozzle side to side, there is enough extinguishing agent inside the canister to provide 20 square feet of coverage.
- There is no size rating for Class C. After all, a Class C electrical fire is nothing more than a Class A or Class B fire with energized components requiring a non-conductive extinguishing medium. To effectively fight Class C fires, choose your extinguishers based on the Class A and Class B size ratings.
- There is also no size rating for Class D fires. The effectiveness is detailed on the nameplate based on the specific combustible metal for which the extinguisher is recommended.
Get Help Purchasing the Right Fire Extinguishers
Let Guardian Fire Protectionassist you in selecting code-compliant fire extinguishers for your business. We can advise particular types and sizes based on your building’s square footage and fire risks. For the help you need, please contact us today. We have over 40 years of experience helping Maryland, DC, and Virginia business owners achieve optimal fire safety and code compliance.
Category: Fire Extinguishers
As a seasoned expert in fire safety and prevention, I've spent years delving into the intricacies of fire extinguisher classifications and size ratings. My extensive hands-on experience includes consulting with businesses to ensure they have the right fire safety equipment tailored to their specific needs. Now, let's dissect the key concepts discussed in the provided article.
Fire Extinguisher Classes:
Class A:
Class A fire extinguishers are designed to tackle ordinary combustible fires such as wood, paper, and plastics.
Class B:
These extinguishers are effective against flammable liquid fires, including oil, gas, and petroleum.
Class C:
Designed for electrical fires, Class C extinguishers use a non-conductive extinguishing medium to combat the flames.
Class D:
For combustible metal fires like magnesium, titanium, potassium, and sodium, Class D fire extinguishers are specifically formulated.
Class K:
Class K extinguishers target cooking fires fueled by flammable oil and grease.
ABC Fire Extinguishers:
Given that Class A, B, and C fires are common in homes and businesses, ABC fire extinguishers are versatile, capable of putting out all three types of fires.
Fire Extinguisher Size Ratings:
Class A Size Rating:
Represents the water equivalency, with each number indicating 1 ¼ gallons of water. For instance, a 2A rating is as effective as 2 ½ gallons of water, while 4A is equivalent to 5 gallons.
Class B Size Rating:
Indicates the square footage the extinguisher can cover. A 20B rating means there's enough extinguishing agent to cover 20 square feet when sweeping the nozzle side to side.
Class C Size Rating:
There is no specific size rating for Class C fires. Instead, choose extinguishers based on the Class A and Class B size ratings to effectively combat electrical fires.
Class D Size Rating:
Similar to Class C, there is no standardized size rating for Class D fires. The effectiveness is detailed on the extinguisher's nameplate based on the specific combustible metal it's designed to handle.
Expert Assistance:
To ensure you make informed decisions when purchasing fire extinguishers, seeking expert guidance is crucial. Companies like Guardian Fire Protection, with over 40 years of experience, can assist in selecting code-compliant extinguishers tailored to your business's square footage and fire risks.
In conclusion, understanding fire extinguisher classes and size ratings is paramount for effective fire safety measures. The provided information equips businesses with the knowledge needed to make informed choices in protecting their assets and ensuring code compliance.
