Smoke Detector Lifespan: How Long Do They Last?

A good smoke alarm is always the first and best defense against a fire that may occur in your home, but even the best smoke detector doesn't last forever. According to the Consumer Product Safety Commission, two-thirds of home fire deaths occur in homes with no smoke detectors or no working smoke detectors.

Life Span

• The U.S. Fire Administration (USFA) says most smoke alarms have a life span of eight to 10 years. When you purchase a new detector, the USFA recommends that you write the purchase date on the inside to know when to change it.

Maintenance

• The USFA recommends that batteries in smoke alarms should be replaced at least once a year. The entire unit should be replaced after eight to 10 years.

Failure Rates

• Little research has been done on when detectors fail. One Canadian study in the early 1980s suggested detectors fail at a rate of 3 percent a year, regardless of age. One former official of alarm manufacturer Pittway told the "New York Times" that the electronic components should last 30 years, but a detector could fail at any time. Changing an alarm every 10 years provides a reasonable margin of safety, he said.