Montgomery Firefighters Switch to Foam

In the future, firefighters in Montgomery County, Maryland will spray foam on building fires rather than plain water. In fact, the trend has already started.

For decades, firefighters there and elsewhere have used foam to contain blazes of flammable liquids on highways. That's Type B foam.

Type A foam is designed for building fires. All of the new fire engines in Montgomery County have the capacity of mixing and delivering either kind of foam.

Division Chief Steve Lohr says testing has proved the Type A foam as generally superior to water for suppressing fires of buildings and their furnishings. The foam sticks to surfaces and cools them faster.

"We estimate the rate of heat absorption is about three times faster with compressed air foam," Chief Lohr told us.

What's the chemical that turns water into foam? A tiny amount of detergent.

"I would describe it as a stronger version of the dishwasher detergent used in your kitchen sink every night." explained Lohr, who described the liquid as safe and easy to clean up afterward.

Montgomery County has 34 fire stations that respond to blazes. Twenty-four of them already have the new combination foam-water trucks. The remainder of the county's fire stations are expected to have foam-water trucks by the end of December.