HUNTSVILLE, Ala. (WHNT) – We go to bed a night with the reassurance if a fire sparks and smoke builds, we will be protected. But WHNT News 19 has recently uncovered a disturbing delay in one type of smoke alarm.
Yes, there are two types of smoke alarms on the market. Ionization smoke alarms detect flames whereas photoelectric smoke alarms detect smoke.
Here’s how they work:
- Ionization-type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, and reduces the flow of current then activating the alarm.
- Photoelectric-type alarms aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.
Bill Loden, Vice President of the American Society of Home Inspectors says therein lies the problem. Loden inspects hundreds of homes every year in the Tennessee Valley. More often than not, Bill finds ionization smoke alarms mounted the walls.
“Ninety-five percent of the homes in this country have this type of smoke detector,” said Loden.
Loden has spent the last several years trying to shed light on what he calls a deadly delay.
The International Association of Fire Fighters is now urging homeowners to make sure their homes are equipped with photoelectric smoke detectors.
“I think the industry has lagged behind,” said Steve Butler, President of Huntsville Fire Fighters Local 1833. “That’s why the IAFF took the bold step last fall and tried to urge all the states to try to change their standards.”
In August, the IAFF said federal, state and provincial officials should require all relevant building standards and codes developed in the United States and Canada to include a mandate for the use of photoelectric smoke alarms. Research has demonstrated that photoelectric smoke alarms are more effective at warning of smoke from smoldering fires than ionization smoke alarms.
“With earlier detection, people have more time to escape a burning structure,” said Butler. “The photoelectric cell is a better application.”
Another problem with ionization alarms isn’t just their slow response times. Fire officials say they are often a nuisance because they randomly sound off when you cook or do other household activities. People become aggravated and disable the alarm, leaving their families unprotected.
WHNT News 19 decided to test both smoke alarms. With the assistance of Loden, we conducted a demonstration using a large-sized aquarium.
Inside the aquarium we placed:
- Foam from a couch cushion
- An ionization smoke alarm
- A carbon monoxide detector
- A hot soldering iron (inside the foam)
We placed a lid on the aquarium and waited for the smoke the build. At three minutes, the smoke set in and quickly blanketed the inside of the aquarium. We also monitored the carbon monoxide detector during our experiment. At 15 minutes the carbon monoxide detector peaks at 1,000 parts per million. Eventually we hit 20 minutes and could no longer see the ionization smoke alarm. As we reached in to check things out, the alarm finally went off.
We duplicated this test again, only the second time we used a photoelectric smoke alarm. At three minutes … the smoke once again set in. But this test was different. The photoelectric smoke alarm went off at five minutes, 48 seconds.
The final result AFTER smoke was present:
- Ionization: 17:00 minutes
- Photoelectric: 2:48 seconds
Steve Butler called our test results “eye opening.”
In the last few years, Vermont, Massachusetts and Iowa have passed legislation either banning ionization smoke alarms or requiring both types to be installed in residential homes and businesses. Tennessee is currently considering legislation.
The national fire death rate in 2009 was 11.0 deaths per million population. The highest death rates by state in 2009 occurred in 1) Arkansas, 2) Mississippi and 3) Alabama. Our state had 21.2 deaths per million. This makes Alabama’s fire death rate nearly double the national rate.
Loden says recent data for residential fire deaths shows there are approximately eight deaths per 1,000 fires. This number has remained largely unchanged over the last 30 years.
“This is a difficult statistic to explain,” said Loden.
Butler agrees.
“It’s hard to defend it. There are a lot more flammable materials in in-house construction nowadays and in residential construction you have more synthetic materials that give off a lot more toxic vapors,” said Butler.
Underwriters Laboratories is the world’s largest product safety testing and certification organization. They issued WHNT News 19 this statement:
“Any smoke alarm that carries the UL mark meets the safety requirements of the UL standard. The recommendation today from UL and fire officials all over the country is that having both photoelectric and Ionization technologies in your home offer the best level of protection in being alerted should a fire occur in your home.”
So while they deem both types of smoke alarms safe, UL recommends you have both.
Alabama State Fire Marshal Ed Paulk also supports both.
“Although either is currently acceptable under Alabama Code, I personally and professionally endorse a dual-type fire alarm system which combines both photoelectric and ionization sensors,” said Paulk.
Leading to the big question: Why are most residential homes and apartments still equipped with ionization smoke alarms?
“Thousands of people have died needlessly in the last 20 to 30 years because of this,” said Loden. “Something must be done.”
WHNT News 19 is sending a letter to lawmakers, along with a copy of our smoke alarms demonstration, requesting they take immediate action for our Tennessee Valley community.
