SMOKE ALARMS

Smoke alarms are devices that are mounted on the wall or ceiling and automatically sound a warning when they sense smoke or other products of combustion.

Although we like to feel safe at home, about two-thirds of our nation's fire deaths happen in the victim's own home. The home is where we are at the greatest risk and where we must take the most precautions. Most deaths occur from inhaling smoke or poisonous gases, not from the flames.

Most fatal fires occur in residential buildings between 11 p.m. and 6 a.m. when occupants are more likely to be asleep. More than 90 percent of fire deaths in buildings occur in residential dwellings.

A Johns Hopkins University study, funded by the United States Fire Administration, found that 75 percent of residential fire deaths and 84 percent of residential fire injuries could have been prevented by smoke alarms.

There are two basic type of smoke alarms:

1. Ionization detectors - Ionization detectors contain radioactive material that ionizes the air, making an electrical path. When smoke enters, the smoke molecules attach themselves to the ions. The change in electric current flow triggers the alarm. The radioactive material is called americium. It's a radioactive metallic element produced by bombardment of plutonium with high energy neutrons. The amount is very small and not harmful.

2. Photo-electric detectors - These type of detectors contain a light source (usually a bulb) and a photocell, which is activated by light. Light from the bulb reflects off the smoke particles and is directed towards the photocell. The photocell then is activated to trigger the alarm.

Choosing a smoke alarm
When choosing a smoke alarm, there are several things to consider. Think about which areas of the house you want to protect, where fire would be most dangerous, how many you will need, etc.

The Carlsbad Fire Department recommends that every home have a smoke alarm outside each sleeping area (inside as well if members of the household sleep with the door closed) and on every level of the home. The building code requires a smoke alarm inside each sleeping area for new construction. On floors without bedrooms, alarms should be installed in or near living areas, such as dens, living rooms or family rooms. Smoke alarms are not recommended for kitchens.

The safest bet is to have both kinds or a combination alarm with a battery back up. Be sure to check for a testing laboratory label on the alarm. It means that samples of that particular model have been tested under operating conditions. Check to see if it is easy to maintain and clean. Be sure bulbs and batteries are easy to purchase and convenient to install.

Installation
The placement of smoke alarms is very important. Sleeping areas need the most protection. One alarm in a short hallway outside the bedroom area is usually adequate. Hallways longer than 30 feet should have one at each end. For maximum protection, install an alarm in each bedroom.

Be sure to keep the alarm away from fireplaces and wood stoves to avoid false alarms. Place smoke alarms at the top of each stairwell and at the end of each long hallway. Smoke rises easily through stairwells. If you should put a smoke alarm in your kitchen, be sure to keep it away from cooking fumes or smoking areas.

Proper mounting of a smoke alarm also is important. You can mount many alarms by yourself, but those connected to your household wiring should have their own separate circuit and be installed by a professional electrician. If you mount your alarm on the ceiling, be sure to keep it at least 18 inches away from dead air space near walls and corners. If you mount it on the wall, place it six to 12 inches below the ceiling and away from corners. Keep them high because smoke rises.

Never place them any closer than three feet from an air register that might recirculate smoke. Don't place them near doorways or windows where drafts could impair the alarm operation. Don't place them on an uninsulated exterior wall or ceiling. Temperature extremes can affect the batteries.

Maintenance
Keeping smoke alarms in good condition is easy. Always follow the manufacturer's instructions. Be sure to replace the batteries every year or as needed. Most models will make a chirping, popping or beeping sound when the battery is losing its charge. When this sound is heard, install a fresh battery, preferably an alkaline type. We recommend replacing smoke alarms over 10 years old.

Replace bulbs every three years or as needed. Keep extras handy. Check the smoke alarm every 30 days by releasing smoke or pushing the test button. Clean the alarm face and grillwork often to remove dust and grease. Never paint a smoke alarm as it will hamper its function. Check your alarm if you've been away from home.

If you're looking for a novel gift for somebody, consider giving them a smoke alarm. It's an interesting gift that can save lives and it shows that you care.

Smoke alarms are recommended to be replaced if over 10 years old.