Emergency responseFlame-retardant grenades help firefighters, first responders
Most hand-held fire extinguishers are pressurized with nitrogen or carbon dioxide to propel powdery potassium bicarbonate, liquid water, or a fluorocarbon at a fire; new device, using potassium carbonate, quells blazes with less risk to firefighters
Good news for firefighters and first responders: A new grenade-like gadget designed quickly to extinguish flames in small quarters, thereby limiting injury to victims as well as firefighters. The new device is becoming an important part of firemen’s arsenals. Scientific American’s Larry Greenemeier writes that more than thirty-seven fire departments along the U.S. east coast now carry Vancouver-based ARA Safety’s FIT-5 (for fire interruption technology). The device, available to firefighters since December, is a means of knocking down or even extinguishing fires in rooms, basements, and attics. The FIT-5 (price for each is around $1,300) is a 9-pound red disk which resembles a land mine and is deployed as a grenade: A firefighter pulls its cord and tosses the disk into the area engulfed in flames; within seconds the FIT-5 releases a wispy cloud of potassium carbonate, a flame retardant that suppresses combustion and disrupts fire at the molecular level.
The company says the device can fully extinguish a class B (fuel-based) fire in a room 2,100 cubic feet or less and reduce fire temperatures from 1,000 to 300 degrees Fahrenheit (540 to 150 degrees Celsius) in less than 10 seconds. The FIT-5 is also designed to control class A (wood-based) fires enough so that firefighters can douse them with water. Firefighters in New York State and New Jersey have successfully contained three fires (in a room on the third floor of a house and two in basements) with the FIT-5 since it hit the market.
The FIT-5 is designed to be most effective in a contained space — the larger the area, the less effective, which is why it is not a good candidate for squelching, say, wildfires.
Most handheld fire extinguishers sold at hardware stores for home use are pressurized with nitrogen or carbon dioxide to propel powdery potassium bicarbonate, liquid water, or a fluorocarbon at a fire. In addition to allowing firefighters to control fires from a safe distance, the FIT-5 could also replace halon fluorocarbons, an effective fire-fighting tool until they were banned in 1994 after it was discovered that they destroy Earth’s ozone layer. Because halon displaces oxygen, it extinguished electrical, grease and other fires that water alone could not, says Robert Kaul, ARA Safety’s technical director. When a firefighter approaches a fire and pulls the rip cord located on the side of the FIT-5 device, this generates a spark of heat
