Not all smoke alarms created equal

Apr 11, 2008

If you thought all smoke alarms were equally effective, think again. According to a recent study by researchers from the Harborview Injury Prevention and Research Center (HIPRC) and the University of Washington in Seattle, photoelectric smoke alarms are much more likely to remain functioning after installation than are ionization alarms. Ionization alarms are the most common type found in U.S. households.

The study, which looked at more than 750 households in Washington State, found that nine months after a smoke alarm was installed, 20% of the ionized alarms did not function, compared to just 5% of the photoelectric alarms. Researchers checked the same alarms six months later and found similar results. The most common cause of a non-functioning alarm was the removal or disconnection of the battery.

Researchers found that ionization detectors were more prone to nuisance alarms, often caused by cooking. Nuisance alarms are the most cited reason by residents for removing or disconnecting an alarm battery. “Many fires in the house start in or around the kitchen, so we know that it is critical to have functioning smoke alarms on the first level, adjacent to the kitchen,” said Dr. Beth Mueller, the study principal investigator and epidemiologist at the HIPRC. “Clearly, photoelectric detectors performed much better in this part of the house.”

Alarms sold for home use in the U.S. are ionization, photoelectric, or combination designs. Photoelectric and ionization alarms operate differently. While both detect particles from combustion, photoelectric alarms use optical sensors and are more sensitive to slow, smoldering conditions. Ionization alarms are responsive to flames by detecting particles from rapid combustion.

Source: Group Health Cooperative Center for Health Studies

Explore further: Best of Last Week – Evidence of quark-gluon interactions, new portable device hack and why we may never live forever

add to favorites email to friend print save as pdf

Related Stories

Airlines on alert as eruption begins in Iceland

12 hours ago

Iceland's Bardarbunga volcano burst forth with a small eruption Saturday under the ice of Europe's largest glacier, scientists said, prompting the country to close airspace over the area.

Two Galileo satellites lose their way

15 hours ago

Two European Galileo satellites launched as part of a navigation system designed to rival GPS have failed to locate their intended orbit, launch firm Arianespace said Saturday.

Volcanic eruption begins under Iceland glacier

15 hours ago

Iceland's Bardarbunga volcano began erupting Saturday under the country's largest glacier after a week of seismic activity rattled the area with thousands of earthquakes, the country's Meteorological Office ...

Recommended for you

Computer games give a boost to English

5 hours ago

If you want to make a mark in the world of computer games you had better have a good English vocabulary. It has now also been scientifically proven that someone who is good at computer games has a larger ...

Saddam Hussein—a sincere dictator?

10 hours ago

Are political speeches manipulative and strategic? They could be – when politicians say one thing in public, and privately believe something else, political scientists say. Saddam Hussein's legacy of recording private discussions ...

Oldest representative of a weird arthropod group

10 hours ago

Biologists at Ludwig-Maximilians-Universitaet (LMU) in Munich have assigned a number of 435-million-year-old fossils to a new genus of predatory arthropods. These animals lived in shallow marine habitats ...

User comments : 0