Water Isn't Always the Answer: A Guide to Extinguishing Different Types of Fires

Most people understand how to extinguish a simple camp fire - douse it with water. However, not everyone knows  that there are many different types of fire and each type has a specific method of extinguishing it. Throwing a pail of water into a fire may not be the best idea when the situation calls for a different method, such as spraying foam or pouring sand on the flames. Understanding these different types of fires and learning the best ways of putting them out is important and will ensure that everyone knows how to react and stay safe in different situations.

Ordinary Combustibles (Class A)

A fire categorized as Class A burns from ordinary materials, such as paper and wood. These fires usually start when the conditions are right, such as a pile of dry wood and paper and a low breeze to fan the flames. Other types of combustible materials include clothing, rubber and plastics, which become fodder for the flames when exposed to extreme heat. Fire extinguishers containing water can easily stop the fire from spreading.

• Fire Extinguisher Information Manual of the Santa Clara County Fire Department. Describes the different types of fire and the specific types of fire extinguishers used to stop them. It also shows the labels that identify each type of fire extinguisher and enumerates the steps in handling a fire extinguisher.

• Five Classes of Fire. New York City Fire Department page on different types of fire and fire extinguishers. Includes images and descriptions of each type.

• Quick Fire Safety Guide. A brief explanation of the types of fire and using a fire extinguisher. References the OSHA information page on fire classes.

• Types of Fire Extinguishers. The University of Oregon page describes the chemicals each type of fire extinguisher contains. Also indicates the duration of discharge, distance of effectiveness, and the mechanism of killing the flames.
• Boat Fire Safety Even on the water, fire safety is necessary! Includes minimum guidelines for fire safety equipment on boats. Also reveals the dangers of using Halon-filled fire extinguishers. Halon was found to thin the shield of the ozone layer. Includes descriptions of the Halon alternatives, FE-241 and FM-200.

Flammable Liquids and Gases (Class B)

The second type of fire, which burns from gasoline, paint thinner, kitchen oils, propane and acetylene, requires a Class B fire extinguisher, which usually contains carbon dioxide. The use of water during these situations increases the risk of endangering human lives. Gasoline and oils float to the water's surface and continue to burn while water spills all over the place. Instead of lowering the temperature through water, cut off the fire's oxygen supply through exposure to carbon dioxide, which turns to white foam when expelled from a pressurized container.

• Flammable Liquids, Gases, and Vapors Department of Industrial Relations regulations guide for flammable liquids, gases, and vapors.
• Safety with Flammable Substances A guide to working with flammable liquids and gases including proper storage and disposal.
• The USFA page on Fire Extinguishers. A very thorough explanation of fire classes and the types of fire extinguishers used to kill them. Enumerates the conditions when a fire extinguisher is applicable for use.

• Extinguishers Basics. Information page at the OSHA website of the US Department of Labor. Explains how fire extinguishers work and the different types of fire extinguishers.
• Fight or Flee? Evacuation plans and procedures page at the OSHA website of the Department of Labor. Learn how to assess the risks and the actions to take when there is a fire.

Electrical Fires (Class C)

The use of water on a Class C electrical fire increases the risk of electrocuting survivors and firefighters. Once the main electrical line is down, use fire extinguishers labeled ABC or BC to kill Class C fires, which often start from faulty electrical equipment or torn electrical wiring. These fire extinguishers contain either carbon dioxide or dry chemical agents that stop air from fueling the flames.

• Safety Training Manual of CEDT. Great graphical explanation of the different types of fire and the steps to take in preventing these fires. Also lists some dos and don'ts for Class A, Class B and Class C chemicals.

• A Factsheet on Home Electrical Fire Prevention Informational guide to preventing household electrical fires.
• Electrical Wiring Faults and Fires This shows how incorrect electrical wiring can lead to electrical fires (includes diagrams of correct and incorrect circuits).
• Understanding Electrical Fires Explains how household appliances, electrical wiring, fuses, and other household items can lead to an electrical fire. Also, lists warning signs to help preventing future fires.

Combustible Metals (Class D)

Some metals also burn hotly when exposed to heat. Fire due to reactive metals, such as potassium, sodium and magnesium, require fire extinguishers specially labeled D. These fire extinguishers usually contain sodium chloride (salt). Lithium and lithium alloy fires, on one hand, require the graphite metal-based powder in a special Class D fire extinguisher developed by the US Navy. Be aware, though, that carbon dioxide strongly reacts to these metals and may worsen the situation.

• Combustible Metals A list of metals and metal compounds that are combustible and need to be extinguished with a Type D extinguisher.
• Proper Handling of Combustible Metal Fires An article on the dos and don'ts of extinguishing metal fires.
• Class D Fires A description of common combustible metals, what they look like, how they ignite, and other pertinent information relating to safe handling of these materials.

Kitchen Fires Involving Cooking Oils and Fats (Class K)

Kitchen fires are similar to Class B fires because water will not stop them. Cooking oil usually causes kitchen fires and throwing water on it will only spread the fire around the kitchen. A fire extinguisher labeled ABC or BC with either carbon dioxide or dry chemicals in it kills a kitchen fire fast. Fortunately, records from USFA indicate that the presence of fire alarms in kitchens lower the rates of death and property loss in kitchen fires.

• Kitchen Fires - Topical Fire Research Series. US Fire Administration/National Fire Data Center. Presents statistical data on kitchen fires dated October 2004.
• Extinguishing Common Household Fires. Very detailed information page at the website of the Fire Department in Tucson, Arizona. Explains the types of fires, fire extinguishers and steps in assessing risks and fighting fires.
• Cooking Fires Facts and Figures from the National Fire Protection Association updated last November 2010. Free download of a fact sheet on home fires.

The US Fire Administration recorded almost 400,000 structural fires, which mostly happen in residential and commercial buildings, occurred each year since 2005. These fires have caused thousands of deaths and injuries and millions of property losses, which translates to countless lives destroyed. Putting them out may not have been easy, but our valiant firefighters competently do so year after year. However, saving lives and property also involves implementation of preventive measures, such as fire extinguishers, which all home and business owners should know how to use and maintain.

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