Fighting small fires involving hazardous chemicals requires one or two persons to extinguish the fire with a portable fire extinguisher. The type of fire extinguisher to use varies by the fire class of the chemical, (A, B, C, or D). US Department of Labor, OSHA standard 29 CFR 1910, Subpart L, explains how to identify the fire protection method that is best for the type of fire you might have to fight in your workplace.
Most combustion fires are carbon-based; the most commonly used fire-fighting media is water. In the case of a fire involving the metal, magnesium, using water adds fuel to the fire much like gasoline adds fuel to a carbon-based fire. This article focuses on small industrial fires that can be extinguished by one or more fire-fighters using a mobile fire extinguisher.
The most common model for depicting the nature of fires is the Oxygen-Fuel-Ignition triangle. By removing any side from the triangle puts the fire out. Most fire extinguishing media combines with oxygen to remove that component from the Fire Triangle to extinguish the fire.
Fire protection methods vary by the fire class of the chemical, (A, B, C, or D). In accordance with US Department of Labor, OSHA standard 29 CFR 1910, Subpart L, the following steps explain how to identify the fire protection method that is best for the type of fire you might have to fight in your workplace.
Identify and learn which portable fire extinguishers are located in your work area are for fighting an A, B, C, or D fire or combinations of classes.
Identify Class A fires. The fuel in a Class A fire includes ordinary combustible materials such as wood, cloth, and some rubber and plastic materials.
Identify Class B fires. This is the fire class most associated with fires involving chemicals.
Identify Class C fires. This type of fire may involve several kinds of fuel and energized electrical equipment where safety to the employee requires the use of electrically non-conductive extinguishing media.
Identify Class D fires. This type of fire involves combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium.
Anticipate receiving instruction and hands-on practice in the operation of a fire extinguisher and the wear of personal protective equipment such as a respirator, goggles or a face shield, gloves, safety hat or cap, and shoe covers.
For more information about the content of this article, refer to MSDS Section 5, “Fire-Fighting Measures.” For information about fire-fighting references, extinguishers, media and other products as well as solutions such as training and other work aids supporting fire protection measures, click on this link to access the blog, “Fighting Fires Involving Hazardous Chemicals.”