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Some smoke detectors may not be doing their job

PITTSBURGH — Target 11 is sounding the alarm about something you may have in your home.

An estimated 90 percent of us have ionization smoke alarms in our homes.

While it does alert you to danger in your home, some experts say it may take too long to warn you in certain kinds of fires.

Dean Dennis's daughter, Andrea, along with four others, were killed in a fire near Ohio State University in 2003.

"She was an honor student, just a beautiful child,” said Dean Dennis.

The house where Andrea Dennis died had six ionization smoke detectors.

"All the kids that died died in their rooms they were in,” said Dennis. "They didn’t have a chance.”

Dean Dennis has made it his mission to warn people about the differences between ionization and photoelectric smoke detectors.

He has an online petition to demand warning labels on ionization detectors.

Most experts and research agrees ionization detectors are generally better at sensing fast, blazing fires. But photoelectric are better at detecting slow, smoky, smoldering fires.

With the help of trained firefighters at the Allegheny County Fire Academy, Target 11 set up photoelectric and ionization detectors, then set a smoldering fire in a closed room.

It took 14 minutes and 12 seconds for the photoelectric detector to sound.

The minutes ticked by and more toxic smoke filled the room.

It took 28 minutes and 19 seconds -- twice the time -- for either of the ionization alarms to go off.

Target 11 also did a second test, setting a fast, flaming fire with a torch and straw.

In this case, all of the alarms went off nearly simultaneously -- less than a minute after the fire started.

Target 11 Investigator Gordon Loesch asked the Division Chief at the Fire Academy, "This is what you expected?"

"Yes,” said Chief Steve Imbarlina.

Imbarlina said the difference has to do with the type of smoke and the way the different technologies detect it.

"Open flame, there is more heat. Heat is energy. Energy is converted to kinetic energy, so that smoke is going to move faster,” said Imbarlina.

The test shows the ionization detector as a slower response in a smoldering fire.

In 2007, the U.S. Commerce Department's National Institute of Standards and Technology submitted a report to Boston City Council showing, "In the NIST experiments, the photoelectric detectors sensed smoldering fires on average 30 minutes earlier than the ionization detectors. The same study demonstrated that ionization detectors responded, on average, 50 seconds earlier than photoelectric detectors during flaming fire experiments."

CLICK HERE to read the full report.

"It's a critical issue the public cannot ignore,” said Dean Dennis.

"Minutes can mean the difference between life and the amount of property damage,” said Imbarlina, who also quickly pointed out that any working smoke alarm is better than none.

According to the National Fire Protection Association, most fire deaths are not caused by burns, but by smoke inhalation.

The Consumer Product Safety Commission states, "Both ionization and photoelectric detectors are effective smoke sensors. Even though both types of smoke detectors must pass the same tests to be certified to the voluntary standard for smoke alarms, they can perform differently in different types of fires."

CLICK HERE for more information from CPSC.   

Ionization detectors have the seal of approval of Underwriters Laboratories (UL), a global independent safety science consulting and certification company.

They write of ionization and photoelectric detectors,  "...each demonstrate superior performance characteristics depending on the specific fire scenario... by remaining technology neutral and instead focusing on establishing state-of-the-art test protocols and improved performance requirements, the consumer will maintain access to new and improved safety technologies coming to market without requiring additional standards revisions or lawmaking."

Critics argue the other problem with ionization detectors is that they're more likely to go off with false alarms, like when cooking.

And when that happens, people tend to disconnect them.

Groups like the U.S Fire Administration recommend that you use both kinds of detectors in your home simultaneously, or buy a duel-sensor alarm that uses both types of technologies.

But the International Association of Firefighters recommends only photoelectric detectors, stating the benefit of a dual-sensor alarm is marginal and more expensive.