Fire sprinkler systems in homes and apartments are meant to extinguish a fire, not make it bigger. Shockingly, although rare, sprinkler systems can make a fire worse if the right precautions aren’t taken. There have been at least three known instances where people were seriously injured or killed because of a flash fire that was caused when the fire sprinkler system went off.
In 2002, at a restaurant in New Jersey, multiple people were burned when a space heater in the ceiling set off the sprinkler system. The heat from the space heater reached a high enough temperature to set off multiple heads in the back patio area. Customers reported seeing a fire ball fill the room along the ceiling and continue inside the restaurant area. Several people were burned.
In 2009, in Truckee California, a father was cooking onions in the kitchen when a grease fire ignited, setting off the fire sprinkler head above. A flash fire erupted upon activation of the sprinkler head. The flash fire set off multiple sprinkler heads throughout the apartment. The father was severely burned. His wife, who was also in the kitchen, died from her burn injuries. The three children were all burned but all survived.
In 2010, a single mother and her 3-year-old son lived in an apartment in Herriman, Utah. In the late afternoon, the two of them laid down on the family room couch to watch a movie. The two of them fell asleep during the movie. At some point, the toddler woke up, retrieved some matches from the kitchen cabinet and began lighting matches on the family room floor. After expending several matches, a pillow caught fire, which set off the fire sprinkler head directly above the pillow fire. A flash fire exploded throughout the apartment, setting off four additional sprinkler heads and blowing out the back bedroom window. Glass blew 45 feet into the parking lot. Mom woke up just before the first sprinkler head went off and remembers quickly being surrounded by flames. She found the toddler in the dining area crouched under the table with severe burns to his arms. They were both severely burned. Mom was in a coma for 6 weeks but survived after a hard fight for her life.
I’m sure you’re wondering how this can happen. Believe or not, many fire sprinkler systems in places with colder climates contain a mixture of water and glycerin or glycol. The mixture is used as an antifreeze to keep the water from freezing in the pipes. When not mixed correctly, the mixture can be flammable and even explosive. When the sprinkler head opens, the water exits the head in a fine mist. The heat from the fire evaporates the water from the mixture leaving only the flammable cloud of glycerin/glycol. The droplets ignite, causing a flash fire.
If you live in a climate that reaches freezing temperatures, there’s a chance that your sprinkler system contains flammable antifreeze. If you live in such an area, and your residence has a sprinkler system, you should contact your landlord or, if you own the residence, contact a fire sprinkler contractor to find out whether your system contains antifreeze. If it does, have the mixture tested for concentration levels. The mixture should never contain more than 49% glycerin/glycol. If it does, then you need to have the mixture replaced with a safer level, preferably below 40%. Check with your local fire department for the appropriate level of antifreeze to use in your area.