Smoke alarms save lives. 

Statistics show that the risk of dying in a fire is twice as high in a home without working smoke alarms than in a home with working smoke alarms.

When you visit a local discount store to purchase a smoke alarm because you recognize that smoke alarms are important to your safety, are you surprised by the choices of alarms available? You may wonder:

  • Are they all the same? 
  • What’s the difference in ionization and photoelectric?
  • Which is best?
  • What are dual sensor alarms?
  • How many of each type do you need?
  • Where in your home do you install them?

A national news show recently questioned the reliability of ionization smoke alarms, suggesting that they may sound too late to warn sleeping residents of a fire. 

McKinney Fire Department spokesperson Stacie Durham points out, “Unfortunately, the story focused on the smoldering fire environment, where ionization alarms are well documented to react slower than photoelectric detectors. But, research shows that the ionization detector reacts faster in the flaming environment than its counterpart, the photoelectric alarm. Both types of alarms are of benefit in the appropriate environment.”

Technology in the smoke alarm (detector) field changes rapidly. There are two types of smoke detection technologies currently in widespread use in the United States. Each features a different activation time depending upon the type of fire (fast-flaming fires versus smoldering fires).

 Photoelectric alarms activate more rapidly in in a smoldering, smoky fire, while ionization alarms activate more rapidly during flame-filled fires. 
  The McKinney Fire Department recommends placement of both types of alarms in your residence for maximum protection. 

To avoid nuisance alarms, it's advisable to place ionization alarms away from fixed cooking appliances.

According to Durham, “Smoke alarms are only effective if they are maintained in operable condition. This means testing alarms monthly by pressing the ‘test’ button and changing batteries annually.”

An even better option, she said, is to install 10-year lithium batteries.

“With alarm technology evolving, we recommend that alarms be replaced every 10 years," Durham said. "With a 10-year battery, you replace the entire unit when the battery expires. While you replace batteries less often, you still test the alarm monthly.”

To assist low-income and senior residents, the McKinney Fire Department participates in the Out to Alarm Texas program by partnering with the Texas Department of Insurance to provide free smoke alarms, batteries and carbon monoxide alarms. 

If you or someone you know is in need of alarms, batteries, or wish to have your existing alarms checked, placement of alarms evaluated, or a home safety visit scheduled, contact the McKinney Fire Department at 972-547-2850, visit or email