We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Safety

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Are Fire Classes?

By H. Terry
Updated: May 17, 2024
Views: 8,315
Share

Fire classes, or categories, are usually defined by the type of fuel or heat source responsible for starting the fire, though, in some cases, classification is also made along the lines of how the fire can be extinguished. Classification varies slightly between world regions as well. Fire classification serves to help people fight fires by quickly matching the type of fire to the most appropriate type of extinguisher. Different fire classes must be dealt with in distinct ways.

There are several sources that can fuel fires. Ordinary combustibles are physical objects, such as wood, rubber or cloth, that will ignite and burn when sufficiently heated. Some types of metal can also be set on fire, but this will normally require special circumstances and more extreme levels of heat. Non-solid fire classes include those involving flammable liquids or gases, electricity, and cooking oils or fats.

Ordinary combustible fires, which are often started on purpose in contained spaces, such as in a fireplace, usually can be extinguished by using water to cool the heat that is causing combustion. This class of fire can also be smothered by foam, depriving the fire of its necessary supply of oxygen. Other fire classes can require more specialized extinguishing agents.

An electrical fire is commonly fought with carbon dioxide, since foam or water could act as a dangerous conductor of electricity. Flammable liquid fires might sometimes also be fought with foam, but gas fires usually require the use of carbon dioxide, halon, or dry chemicals to interrupt the chemical reactions causing the fire. Metal fires are usually fought using dry powders such as graphite, sodium chloride or copper powder while large fires involving cooking oils or fats require a wet chemical extinguisher. Small kitchen fires, for example a tiny flame in a cooking pan, typically can be stopped by placing a metal lid over the fire, thereby restricting the available oxygen.

There is some overlap in the ways that different kinds of fires can be extinguished. Largely because of this, world regions have developed subtly distinct systems of fire classification. For example, in the American system, liquids and gases are categorized in the same class because they are frequently fought in a similar way. They are classified as two separate classes in both the Australasian and European systems. In all systems, fire classes are identified by a given letter; for example, a "Class A Fire" categorizes the ordinary combustible class in all regions. The particular letters assigned to each type of fire otherwise vary somewhat between regions, however.

Share
About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
https://www.aboutmechanics.com/what-are-fire-classes.htm
Copy this link
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.