The use of foam is, traditionally, not an everyday occurrence. However, when it is needed, the operation must be flawless and efficient. Today, many fire apparatus are equipped with pre-plumbed foam systems; these are great, but again, they are only effective if we know how to properly execute their function.

Foam is an effective firefighting agent because of its ability to cool, smother, separate, and suppress vapors. Since foam is a water-based extinguishing agent it has the ability to absorb heat energy as well as cool adjacent fuels. In addition, foam creates a blanket, which separates the burning vapors from the fuel; such is the case for Class B fires. This foam blanket also inhibits oxygen availability, which again aids in the full extinguishment process.

There are many types of foam on the market. They vary depending on their intended class of fire and concentration. It is key to match the class of foam with the class of fire it is intended to extinguish.

Many foams can extinguish a variety of fires. For example, aqueous film-forming foam is able to extinguish class A and B fires. Traditionally, compressed air foam systems have dual tanks with separate class A and class B foams, allowing the apparatus officer to determine the needed foam for the incident. No matter what systems you have, make sure you are proficient in its use.

When applying foam, there are three generally accepted methods:  bank-down, roll-on, and rain-down. Banking down is a great method when the fire or area to cover is near a wall or near an object. During this technique, the nozzle firefighter deflects the foam stream against the wall and allows the foam to “bank” onto the fire or spill, creating an extinguishing blanket.

The roll on method is a similar deflection method where the firefighter deflects or “rolls” the foam onto the product via the ground.  The nozzle is pointed toward the ground near the fire or spill, and the foam is gently rolled onto the fire.

The rain down method uses the reach of the stream to affect extinguishment. The firefighter simply points the stream up and allows the foam product to “rain” onto the fire or spill. Use caution here to ensure to the foam is hitting the target.

Foam should not be intimidating; it can be an excellent additive to aid in extinguishment and is a necessary tool for certain fires. Take the time on your next tour to practice with your foam system and ensure your operational proficiency.

Download this drill as a PDF HERE (383 KB)

Brian Zaitz is a 14-year student of the fire service, currently assigned as the captain/training officer with the Metro West (MO) Fire Protection District. Brian is an instructor with Engine House Training, LLC as well as instructor at the St. Louis County Fire Academy.  Brian holds several degrees, including an associates in paramedic technology, a bachelors in fire science management, and a masters in human resource development. Brian is currently and accredited chief training officer and student of the National Fire Academy’s Executive Fire Officer Program.

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