TONICA — Water is typically the first thing to come to mind when thinking of firefighters battling a blaze, but there’s another equally important tool to help them extinguish potentially deadly fires — foam.
On the evening of June 25, residents may have seen the members of the Tonica Volunteer Fire Department (TVFD) conducting an exercise with low-expansion foam in their parking lot. The foam was provided to the department through an anonymous donation.
“Firefighting foam is used for fire suppression,” TVFD Training and Public Information Officer Rick Turri said.
“Its role is to cool the fire and coat the fuel, preventing its contact with oxygen and resulting in the suppression of the combustion,” TVFD Training and Public Information Officer Rick Turri said.
Tonica firefighters reviewed the equipment needed, its required maintenance, the various types of foam and the different products they can be used on, as well as learning what not to do with it.
Since firefighters must estimate how much foam will be used before it is applied, they also studied the proper mixture rates of the concentrate.
“Class A foams were developed in mid-1980s for fighting wild land fires. They lower the surface tension of the water, which assists in the wetting and saturation of Class A fuels with water. This aids fire suppression and may prevent re-ignition,” Turri said.
Class B foams are designed for class B fires, or flammable liquids. The use of Class A foam on a Class B fire may yield unexpected results, as they are not designed to contain the explosive vapors produced by flammable liquids.
Class B foams have two major sub-types. Synthetic foams are based on synthetic surfactants and provide better flow and spreading over the surface of hydrocarbon-based liquids for faster knockdown of flames. Aqueous film forming foams (AFFF) are water-based and frequently contain hydrocarbon-based surfactants.
Alcohol-resistant, aqueous film-forming foams (AR-AFFF) are resistant to the action of alcohols and can form a protective film.
There are also protein foams that contain natural proteins as foaming agents. Unlike synthetic foams, protein foams are bio-degradable and flow and spread slower, but provide a foam blanket that’s more heat-resistant and durable.
“Every type of foam has its application. High-expansion foams are used when an enclosed space, such as a basement or hangar, must be quickly filled. Low-expansion foams are used on burning spills,” Turri said.
There are also other types of fire-suppressing foam, each with their own specified use, and proper training is crucial.
The first firefighting foam was invented by the Russian chemist Aleksandr Loran in 1902. He lived near the country’s oil industry and was inspired by the common sight of the large, deadly, and difficult-to-extinguish fires he had witnessed.
From the 1940s onward, there have been new developments in foamed fire suppression in nearly every decade.
The TVFD and Ambulance Service operate solely through donations from local businesses and residents and various fundraising efforts. They are one of the few departments that do not operate through taxation, and they greatly appreciate the support received from their community.