A smoke alarm.

Recent news about ionization and photoelectric alarms:

NFPA Fact Sheet on Ionization versus photoelectric smoke alarms

Types of Smoke Alarms

Residential smoke alarms use two types of technologies: ionization and/or photoelectric. Each type has been found to generally respond best to different types of fires in studies by Underwriters Laboratories and the National Fire Protection Associationís Fire Protection Research Foundation. Ionization smoke alarms respond best to flaming fires, and photoelectric to smoldering fires.

The National Fire Protection Association and the International Association of Fire Chiefs both recommend installing both types of alarms, or dual alarms that incorporate both technologies. (NFPA Journal Sept/Oct 2007, and Position Paper on Smoke Alarms--Ionization and Photoelectric Technology, IAFC Fire and Life Safety Section, August 2007, International Association of Fire Chiefs).

Basic Smoke Alarms

  • battery-operated (can be hard-wired)
  • low cost
  • available at hardware and home stores

Basic smoke alarms are adequate as long as they can successfully alert everyone in your home. Depending on your needs, you may need to consider other types of alarms.

Can everyone in my family hear the smoke alarms?

A basic smoke alarm. Basic smoke alarms may be difficult to hear because of the high pitched noise that they emit. If anyone in your house has trouble hearing the alarms, consider the alternatives below.


A voice-recorded smoke alarm. Pre-recorded Voice Alarms use a recorded voice message alerts you to the fire instead of a high pitched noise. Since speech is somewhat lower pitched and easier to hear, these can be a useful option.


A vibrating smoke alarm. Vibrate or Shaker Smoke Alarms use a vibrating device to shake a bed or chair to awaken and alert you of fire.


A strobe smoke alarm. Strobe Alarms use an extra bright strobe light to alert you of fire. Some strobe alarms also include a vibrator device.


Hard-wired smoke alarms

If your smoke alarms are wired into your homeís electrical system, you will need to have a qualified electrician do the initial installation or install replacements. Hard-wired alarms may or may not have a battery back-up. Test your hard-wired smoke alarm just as you would a battery-operated alarm. The entire unit should be replaced every 8-10 years. Like battery-operated alarms, most hard-wired alarms use a high-pitched electronic horn which is difficult for some people to hear.

The UL Tested symbol. We recommend you choose an alarm that has a seal of approval from the testing agency, Underwriters Laboratory and has the UL mark on packaging.


For Assistance

Help is a phone call away. Your local fire department is standing by and ready to assist you in testing or installing alarms, as well as helping you develop and practice an exit plan for your home. Call your local fire department today for assistance.