UW study finds smoke alarm differences in two major types

Researchers in Seattle say that photoelectric smoke alarms are more likely to continue working than the more-common ionization alarms.

Their study found the ionizing detectors were more prone to nuisance alarms caused by cooking, which leads people to disconnect the battery. No battery is the most common reason alarms don't work.

Ionization alarms respond to combustion flames. Photoelectric alarms use optical sensors.

The study found that nine months after a smoke alarm was installed, 20 percent of the ionized alarms did not function, compared to 5 percent of photoelectric alarms.

The study of 750 households in Washington was conducted by the University of Washington and the Harborview Injury Prevention Research Center. It appears in the April issue of the journal Injury Prevention.