Underwriters Laboratories Inc.

About UL | Careers | Contact Us

Product Safety Tips:

Smoke Alarms

Few of us realize how easily -- and how quickly -- fire can destroy our homes and take the lives of those we love. Fortunately, a product is available that can help protect us against fire… the smoke alarm.

By providing an early warning in the event of fire, smoke alarms may allow you and your family sufficient time to reach safety. Many people have neglected to install smoke alarms despite their life-saving potential and low cost. Even those who do have smoke alarms often take them for granted -- forgetting that they need some attention to continue working properly. Underwriters Laboratories Inc. (UL) offers the following tips for purchasing and maintaining smoke alarms.

Cut your family's risk in half - buy smoke alarms today

Experts report that consumers may cut their risk of dying in a home fire in half simply by having a smoke alarm in their homes. Smoke alarms are available at nearly all hardware, department and discount stores, often for under $20.

Look for the UL Mark

When you purchase a smoke alarm, look for the UL Mark on the product as well as on the packaging. The UL Mark tells you that a representative sample of the smoke alarm has been evaluated by Underwriters Laboratories Inc. (UL) to nationally recognized safety requirements. It also means that UL conducts follow-up evaluations to countercheck that samples of the smoke alarm continue to meet these safety requirements.

Photoelectric and Ionization type alarms

There are two types of smoke alarms available today: photoelectric and ionization. When smoke enters a photoelectric alarm, light from a pulsating light source in reflected off the smoke particles onto a light sensor, triggering the alarm. When smoke enters an ionization alarm, ionized air molecules attach to the smoke particles and reduce the ionizing current, triggering the alarm. While photoelectric smoke alarms generally respond faster to smoldering smoke conditions and ionization smoke alarms generally respond faster to flaming fire conditions, both types provide adequate protection against fire. Combination smoke alarms featuring both photoelectric and ionization technology are also available at hardware, department and home improvement stores.

There's safety in numbers

Install at least one smoke alarm on each floor of the house or residence and outside all sleeping areas. Some fire safety advocates recommend installing smoke alarms inside each sleeping area if sleeping with the door closed.

Test, clean and maintain your smoke alarms

Working smoke alarms are needed in every home and residence. Test and maintain your smoke alarms at least once a month, or follow the manufacturer's instructions. Smoke alarms most often fail because of missing, dead or disconnected batteries. Replace batteries at least once a year.

Practice a fire escape plan

In addition to installing smoke alarms in your home, the safety experts at UL also recommend that you develop a fire escape plan and practice it at least twice a year with all members of your household. In the event of a fire, every family member should know at least two ways out of each room. Stay as close to the floor as possible during your escape. Hot air and smoke rise, so the air nearest the floor may be safer to breathe. If you encounter a closed door during your escape, feel the door before opening it. If it's hot to the touch, use another exit. The heat could indicate fire on the other side of the door. Teach your children how to escape in case of a fire -- not to hide under a bed or in a closet.

Some individuals, particularly children, older people and those with special needs, may not wake up to the sound of a smoke alarm. You should be aware of this when developing your home fire escape plan.

Designate a well-lit place, a safe distance away from your home, where everyone will meet in the event of a fire. This will help firefighters determine if anyone else is still inside the home. And remember; never return to a burning building for any reason.

Review of smoke alarm installation, safety and maintenance

  • Read and follow the manufacturer's installation and maintenance instructions exactly.
  • Install fresh batteries in your smoke alarms at least once a year.
  • Don't allow anyone to disconnect or "borrow" the batteries from your smoke alarms. A smoke alarm can't work unless it's connected to a power source.
  • If a smoke alarm's warning alarm sounds, don't panic. Stay close to the floor and get out of the building. Before opening any doors, check the temperature. If the door feels hot to the touch, don't open it. Use an alternate exit.

Top of Page