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Pay Attention to the Chirps

Improve safety with smoke alarms and detector upgrades

APRIL 2022

by Derrill Holly, Contributing Writer

If that old smoke detector, discolored and stained with paint or years of household grime, could send you a message silently, it might say, “Please, replace me.” Those lifesaving warning devices designed to alert us to smoke and fire were never meant to last forever.

The National Fire Protection Association recommends that a working smoke detector be installed in every bedroom, on every level of a home and in hallways.

“The National Fire Protection Association and Underwriters Laboratories suggests replacing smoke alarms every 10 years,” says Nicolette Nye, a public affairs specialist with the Consumer Product Safety Commission. Both organizations cite sensor degradation rates of 3% per year for their replacement recommendations.

“After 10 years, there would a potential of a 30% failure rate,” said Nye, who also cited a CPSC recommendation that consumers look for smoke alarms rated or certified by Underwriters Laboratories, designated by the symbol UL, or the Electrical Testing Laboratories, marked with the ETL logo.

Both smoke alarms and carbon monoxide detectors are designed with a timeframe or useful lifespan of 10 years, says Shawn Mahoney, a National Fire Protection Association technical services engineer.

“Once they start to reach their end of life, consumers may notice alarm signals — typically a chirping sound that is either a low battery or an indication of the device’s end of life, meaning that it’s time the unit was replaced,” says Mahoney.


The NFPA recommends that batteries be replaced once a year, and urges you to test the unit once a month as an added precaution against failure. Chirping, prompted by a drained battery, will typically stop within seven days and, when that happens, the unit stops working.

“If you’re just waiting to hear the sound and not testing regularly, there’s a possibility that you’re going to miss that, especially if you have battery-only systems,” Mahoney says.

Carbon monoxide detectors sound the alert before carbon monoxide reaches life-threatening levels. (Photo Courtesy: Abi Begum)

According to the CPSC, smoke alarms and carbon monoxide detectors represent good investments in your family’s safety, says Nye, emphasizing that both types of devices should be replaced after 10 years.

“Consumers who have working smoke alarms in their homes die in fires at about half the rate of those who do not have alarms,” Nye says. “Install working carbon monoxide detectors on every level of the home and outside of sleeping areas. CO detectors are designed to sound the alert before carbon monoxide reaches life threatening levels.”


Design improvements are another great reason to consider replacement of older units. Ionization smoke alarms made their debut in the consumer market in 1970.

Photoelectric smoke detectors were patented in 1972, and the first 10-year lithium battery-powered smoke alarms hit the market in 1995. Since then, units using the best features of all three technologies have become popular.

Many states have upgraded building codes to require hardwired smoke alarms with battery backup power, and carbon monoxide detectors in all new residential construction.

As fire codes have evolved to require smoke alarms in close proximity to cooking appliances, manufacturers have improved the technology, says NFPA’s Mahoney.

“They can distinguish between an actual fire event in the home and cooking fumes, reducing the incidence of nuisance alarms,” he adds.

Derrill Holly writes on consumer and cooperative affairs for the National Rural Electric Cooperative Association.