Investigation: Some smoke detectors are cause for alarm

Investigation: Some smoke detectors are cause for alarm

HENRICO, VA (WWBT) - Just because you have working detectors doesn't mean they will immediately alert you to a fire.

On Your Side Investigator Rachel DePompa worked with a local fire department to set several fires and demonstrate how smoke detectors really work.

Flames shooting from a Chester roof in the dark of night. Parents on a sunny morning, rushing to a fire at a Chesterfield home daycare. You never know when flames will break out. According to the State Fire Marshal's office, in 2014 74 Virginians didn't make it out of their homes alive.

"You have about a 30 percent chance of getting out of a house that's on fire if you do not have a working smoke detector," said Henrico Fire Department Capt. Danny Rosenbaum.

Even with a working alarm, every second counts, and as we've discovered, not all smoke detectors work the same way. In fact, one type of alarm may give you a little more time to get out of a deadly fire.

There are three types of alarms on the market: Ionization detectors are in 90 percent of homes. They're designed to detect fast, flaming fires. Photoelectric detectors are designed to catch slow, smoldering fires. There are also alarms that combine the two technologies.

We teamed up the Henrico Fire Department at their fire training facility in Glen Allen.

Members suited up while two NBC12 photojournalists set up seven cameras to catch every angle of the department's demonstration.

We placed six smoke detectors on a makeshift ceiling -- two ionization, two photoelectric and two combination alarms. Henrico firefighters threw wood and straw into a barrel and lit it up using a flare. Within 20 seconds of firefighters starting that flaming fire in a barrel, the ionization and combination alarms went off.

Two seconds later they were followed by the photoelectric alarms.

There was quite a difference when the firefighters created a slow, smoldering fire. This time the firefighters wet the straw in the barrel, lit a flare and threw it in.

They covered this smoldering fire with a board. Within 30 seconds, the photoelectric and combination alarms caught the smoke and went off. We waited two minutes for just one of our ionization alarms to finally sound. It took a total of three minutes for the second ionization alarm to go off.

"You never know what type of fire you're going to have, whether it's going to be a smoldering or a flaming fire," said Rosenbaum. He called the experiment eye opening. "The big surprise was the amount of time that it took, that there was up to a two-minute delay for the ionization to go off versus the photoelectric."

Even more eye opening, our sister station in Alabama also ran the same demonstration. But, this test didn't have the smoke detectors directly above the fire. It took 30 minutes for the ionization alarms to kick in and detect a slow smoldering fire.

Those photoelectric alarms that catch the smoldering fires went off immediately in all our demonstrations. The technology gives you anywhere from a two-minute to a 30-minute heads up, depending on the situation.

Several National fire protection and firefighter organizations now recommend all homes use both technologies. Some states are even passing laws requiring property owners to install photoelectric detectors.


Consumer Product Safety Commission recommendations (PDF)

Statement from First Alert on its packaging:

Dual sensor technology is the preferred choice of fire service professionals for its ability to detect both flaming and smoldering fires. Ionization technology smoke detectors are generally more sensitive than photoelectric technology smoke detectors at sensing small particles, which tend to be produced in greater amounts by hot, flaming fires, that are consuming combustible materials rapidly and may spread quickly. Photoelectric smoke detector technology is generally more sensitive than ionization smoke detector technology at sensing large smoke particles, which tend to be produced in greater amounts by smoldering fires, which may smolder for hours before bursting into flame.

Statement from Kidde from its website:

Because no one can know when a fire will occur or what type of fire they will have in their home, virtually every recognized fire authority and safety expert – including the International Association of Fire Chiefs (IAFC), the National Fire Protection Association (NFPA), the U.S. Fire Administration (USFA), Consumer Product Safety Commission (CPSC) and Underwriters Laboratories (UL) - recommend having both photoelectric and ionization alarms for optimal protection against flaming and smoldering fires. Kidde supports and states this recommendation on its packaging, website and in its owner's manuals. Kidde offers photoelectric and ionization smoke alarms as well as a dual-sensor alarm that combines both technologies in one unit, all of which meet the current UL standard for smoke alarms and can be purchased nationwide at retailers or online.

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