Deadly Delay: Part Two

At the beginning of the test...
Published: .
Updated: .

Bob Segall/13 Investigates    

The most popular type of smoke detector in the United States tends to provide far less warning and escape time during one of the most deadly types of fires. That is the finding of a WTHR smoke detector test conducted in partnership with the Indianapolis Fire Department.

The test, conducted in April at the Indianapolis Fired Department Training Academy, surprised members of the Indianapolis Fire Department who witnessed the results.

"I was quite shocked," said IFD public information officer Gregg Harris.  "When you see something like this first hand, it opens up your eyes."

WTHR conducted the test to compare smoke detectors with photoelectric and ionization technology.

Ionization smoke detectors are considered more sensitive to fast-burning flaming fires such as kitchen fires. Photoelectric smoke detectors usually respond more quickly to slow-burning, smoldering fires, such as those resulting from electrical short circuits or cigarettes that are accidentally dropped onto couches or mattresses.

During the three-hour test, 13 Investigates created a smoldering fire by placing a 750-degree soldering iron inside the cushions of a couch. Three different smoke detectors were placed about twelve feet away: a photoelectric smoke detector, an ionization smoke detector, and a dual sensor smoke detector that features both ionization and photoelectric technology.

Three out of four times, smoke detectors with photoelectric sensors sounded long before the ionization smoke detectors, providing as much as 26 minutes of extra escape time during the smoky fires.

In some cases, the testing room was filled with thick smoke and dangerously high levels of carbon monoxide gas before the ionization smoke detectors sounded.

"Now that's a big problem," said Jay Fleming, a deputy fire chief from the Boston Fire Department who spent years studying the performance of smoke detectors during slow-burning fires. At one point during the WTHR test, Fleming commented:

"If it's like this and you wake up in the middle of the night, there is very little chance you're going to be able to get out of the house."

Along with WTHR photojournalists Bill Ditton and Steve Rhodes, I wore an oxygen mask and firefighter turnout gear during the testing, which allowed our crew to videotape and document the test with eight separate video cameras.

Lag in warning times

Those cameras show the large discrepancy in warning times between photoelectric smoke detectors and the much more popular ionization alarms, which account for an estimated 80% of all smoke alarms sold in the United States.

Ionization alarms can be purchased for as little as $5, while smoke detectors with photoelectric technology cost between $10 and $15. Dual sensor smoke alarms (sometimes called combination alarms) containing both types of technology cost around $25.

13 Investigates found very few people know there are different types of smoke detectors and, until this test, most IFD firefighters did not realize how much extra time a photoelectric smoke detector can provide in a smoldering fire. Because smoldering fires often burn for hours while their victims are sleeping, that type of fire accounts for a large percentage of the approximately 3,000 fire-related deaths that occur each year in the United States.

"I had no idea there was such a big difference," said one firefighter. "It's a real eye opener. I'm going to change my smoke detectors."


Smoke alarm manufacturers suggest all homes and apartments be equipped with BOTH photoelectric and ionization smoke detectors (or dual technology smoke detectors) to provide the maximum protection and greatest escape time during a fire.

Smoke detectors should be replaced every ten years and batteries should be checked twice a year to make sure they are working.

See the best placement for fire alarms

Coming up Wednesday night on Eyewitness News: Photoelectric smoke detectors are in short supply at many area retailers and, because of the tremendous response to WTHR's Deadly Delay investigation, the supply of these smoke detectors in central Indiana has dwindled even more.

Wednesday night, find out how you can get dual technology smoke detectors (featuring both photoelectric and ionization technology) at a big discount to help protect you and your family. We'll tell you more about WTHR's community service project to help thousands of Hoosiers Wednesday night on the Nightbeat.

Test results

Test #1
First Alert dual sensor  18:00
First Alert photoelectric  23:38
First Alert ionization   33:45

Kidde ionization  27:16
Kidde dual sensor  28:50
Kidde photoelectric  29:30

Test #2
First Alert photoelectric  16:21
First Alert dual sensor   16:38
First Alert ionization   42:10

Kidde photoelectric  33:30
Kidde dual sensor  34:30
Kidde ionization  38:39

See statements from Kidde and First Alert.

Smoke Detector Reservation - WTHR-TV, hhgregg and First Alert are arranging to ship several thousand dual-sensor (featuring both ionization and photoelectric technology) smoke detectors to Central Indiana. Click the link to reserve yours.

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