Smoke Alarms Save Lives!

One of the most important fire safety devices for the home is the smoke alarm. After becoming generally available in the early 1970’s home smoke alarm sales grew rapidly and the price fell, so that by 1991, 88% of US homes had at least one, and alarms could be purchased for under $10. Several studies have concluded that when working smoke alarms are present, the chance of dying from the fire is cut in half. The smoke alarms currently in place have saved thousands of lives, but several problems exist. First, the 12% of homes without alarms have more than half of the fires; second, it is estimated that a third of the smoke alarms in place are not working, often due to failure to replace a worn out battery; and third, many homes do not have as many smoke alarms as are needed to protect the occupants properly.

 

How Many Alarms are Needed?

The primary job of our smoke alarm is to protect you from fires while you are asleep. Thus, your alarms should be located between any sleeping persons and the rest of the house – outside bedrooms or sleeping areas. But tests conducted in the 1970’s clearly showed that this might not be enough. In multi-story homes, fires on a floor level without a smoke alarm can grow to dangerous conditions before sufficient smoke can rise in a stairway to set off an alarm on the upper floor. Based on this observation, most codes require that additional smoke alarms be located on each floor level of the home. A closed door provides protection from smoke on the other side, but will also prevent smoke from reaching a smoke alarm. This is particularly a problem in bedrooms. If you sleep with your bedroom door closed, you should add a smoke alarm in the bedroom; particularly if you smoke in the bedroom or there is a TV, air conditioner, or other major appliances in the bedroom that might start a fire. If you sleep with the bedroom door open, the alarm in the hall outside will detect a fire in the bedroom or elsewhere. There are a few places where a smoke alarm should not be placed. These include kitchens and garages (cooking fumes and car exhaust are likely to set them off) and unheated attics and crawl spaces (where it can get too cold or hot for the electronics to work properly). Fires beginning in these areas are generally detected by the other smoke alarms in enough time to escape safely. If an alarm is desired in these spaces, heat detectors are available. But remember that the smoke alarms are the primary safety devices in any home protection scheme.

 

What Kind of Smoke Alarm Should You Get?

There are two types of home smoke alarms available; the ion type and the photoelectric type. The ion type reacts faster to open flaming fires and is usually the least expensive. The photoelectric type reacts faster to smoldering fires and is less likely to react to cooking. Both types provide good protection and can be used without worry. If you need more than one alarm, you might get one of each. There are also multiple ways to power smoke alarms. Most operate on a battery (usually 9 volt), which should be replaced at least once a year. When the battery needs changing, the smoke alarm will begin to “chirp” every 20 seconds or so, this will persist for a month. This is most likely to start in the middle of the night (when the temperature in the house drops) causing you to get up and remove the battery so you can sleep. To prevent this nuisance you should pick a special day and give your alarms new batteries once a year. Some fire safety organizations promote “change your clocks, change your batteries” when the change is made back from daylight savings time each fall. Always make sure that you use the right battery—the required battery type is marked on the alarm near where the battery goes. Smoke alarms installed in a house may be operated from the household electrical power and not need battery replacement. This type of alarm has a “power on” light to tell you that the alarm has power. Smoke alarms are available which run on house power but also have a battery in case the main power fails. Both types of alarms need to be tested monthly and batteries should be replaced yearly just as with the battery-only operated type.

 

Robert Gentile; A.S., C.F. I.

Fire Investigator

Palm Beach County Fire Rescue