Chief John Vance of the Harris Township (Ind.) Fire Department has been a proponent of foam since his rookie days nearly two decades ago. Back then, he was a firefighter at a Minnesota department where 3M's Light Water foam concentrate was batch-mixed directly into apparatus tanks. Batch mixing wasn't controllable, but the foam solution that resulted from the technique let the department's water go further, he said.

Now, Harris Township has two Class A engines that are used to protect a 2,200-square-mile area that doesn't have fire hydrants, Vance said. He said the foam sticks to surfaces and “stops structure fires based on my previous experiences with just plain water.”

Using foam for firefighting isn't new. It's been used for more than 25 years by the Navy, wildland firefighters and rural departments. In the earlier applications, as seen in Vance's experience, a foam concentrate was batch-mixed directly into an apparatus' tank. Some departments still follow this practice. But today departments today are using compressed-air foam systems. CAFS include a water tank, a foam concentrate tank, a fire pump, a foam proportioner and an air compressor. The system creates a foam blanket that sticks to surfaces and makes water five-times more effective, said Dominic Colletti Jr., president of the CAFS Institute. CAFS produce finished foam — what's used on the fire — by injecting compressed air into the foam solution's stream. About 90% of the solution then turns into bubbles, and a ball valve or smoothbore nozzle is used as a discharge device. The finished foam helps water soak into Class A materials, such as blown insulation, and decreases the total water supply needed to put out a fire.

As with any technology, there are pros and cons to Class A foams and CAFS. In Colletti's opinion, the biggest benefit is the increase in firefighter safety because CAFS decrease hose-line weight and reduce firefighting time in smoky environments, thereby minimizing cardiac risks for firefighters. Colletti said the use of foam also lessens property damage because fewer gallons of water are used. In a typical structure fire, the first engine company may have 750 to 1,000 gallons of water in a tanker to pour on a fire. Foam sticks to surfaces and puts the fire out more quickly, which means less water is used to cool the fire, he said.

“Tactically, it lets firefighters run a defensive operation and a property exposure/protection application where they are able to use CAFS to make aggressive fire stops, which saves property and potentially impacts a victim's life safety inside a structure,” Colletti said.

Foam helps reduce property damage, agreed Vance. In fact, he said insurance agents in Harris Township have met with his team about home-insurance claims and said the use of foam saved one particular homeowner $200,000.

“He looked at the amount of fire that was in the house and the lack of fire damage … and I'm talking about floors and drywall that didn't have to be replaced because less water was used,” Vance said. “So from a customer-service standpoint, using less water on these fires has really helped lessen water and property damage.”

Vance also said rekindles are less frequent when his department uses Class A foam because it breaks down the surface tension of the water so it soaks into Class A material. In addition, he doesn't have to worry about tankers dripping as much water that in Midwestern winters quickly turns to ice on the streets and walkways. Ice becomes a danger to firefighters moving quickly from the rig to the fireground and can lead to a broken leg or other injuries, he said.

Foam's Cons

Cost is the biggest downside of foam. A 5-gallon pail of Class A foam averages $70. New nozzles and air compressors also increase the cost. In fact, a foam-equipped apparatus can run a department around $400,000. In addition, running Class A foam through CAFS increases maintenance costs, Vance said. Firefighters must flush out the system regularly and remember to turn off air compressors.

“For example, if you leave the air compressor on without the truck flowing water, you can burn out the compressor,” he warned.

In addition, there has been some concern about foam's environmental impact. Data implies that fire-suppression chemicals have adverse effects on water quality, and subsequently to fresh-water fish. Many modern fire chemicals are lethal to aquatic life, wrote Kostas Kalabokidis, a geologist with the University of the Aegean in Mytilene, Greece. Kalabokidis said ammonia was the most toxic of all ions in fire-chemical compounds, affecting certain invertebrate aquatic organisms (such as shrimp) and the egg-sac fry of certain vertebrates (such as salmon and trout).

Foam's effect on the environment is a concern of Mike Richardson, who is a 33-year fire-service veteran and current fire chief of Woodbury Public Safety in Minnesota. His team of firefighters uses foam as a standard operating procedure on all structure fires. But he has heard that there may be negative environmental impacts with the use of certain foams. As a result, he's started to compare products on the market for the most enviro-friendly alternative.

“We've been evaluating other options,” Richardson said. “We've started to look at … products to see if there is a better solution that's more environmentally friendly out there that we should be using.”

Even with the cost and environmental concerns, foam still is used by many departments across the country, said Michael Thurlow, who has served as chief of the Scarborough (Maine) Fire Department since 2001. Thurlow said his department, which is almost completely bisected by a turnpike. One side of town is urban, while the other side is rural. “We don't have public water supply in the rural area of town, so we want to be as efficient as possible when fighting fires and use the least amount of water as possible,” he said.

Thurlow said his department bought its first CAFS truck in 2004 and now has four out of its six front-line apparatus equipped with CAFS. The trucks cost around $370,000 apiece, and CAFS lets the department uses less water on structure fires. However, using the CAFS system has not been a seamless transition for all line operators. There's a training curve. So he advised fire departments to work with vendors to get factory training, where manufacturers' instructors can provide hands-on training to pump operators at the fire station.

“You add another layer of complication for the pump operator, so it does take training for the folks handling the lines,” Thurlow said. “But most of it is hands-on so you have to get out and use it. You have to understand how it works. You have to be in live-fire applications to really see the benefits.”

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