The following information was provided by the US Fire Administration

In the event of a fire, properly installed and maintained smoke alarms will provide an early warning signal to your household. This alarm could save your own life and those of your loved ones by providing the chance to escape.

Why should my home have smoke alarms?

In the event of a fire, a smoke alarm can save your life and those of your loved ones. They are the single most important means of preventing house and apartment fire fatalities by providing an early warning signal -- so you and your family can escape. Smoke alarms are one of the best safety features you can buy and install to protect yourself, your family and your home.

Okay, where do I put them?

Install smoke alarms on every level of your home, including the basement. Many fatal fires begin late at night or in the early morning. For extra safety, install smoke alarms both inside and outside the sleeping area.

Also, smoke alarms should be installed on the ceiling or 6 to 8 inches below the ceiling on side walls. Since smoke and many deadly gases rise, installing your smoke alarms at the proper level will provide you with the earliest warning possible. Always follow the manufacturer's installation instructions.

How do I keep my smoke alarms working?

Smoke alarms are very easy to take care of. There are two steps to remember.

1. Simply replace the batteries at least once a year.
   Tip: Pick a holiday or your birthday and replace the batteries each year on that day. Some smoke alarms now on the market come with a ten-year battery. These alarms are designed to be replaced as a whole unit, thus avoiding the need for battery replacement. If your smoke alarm starts making a "chirping" noise, replace the batteries and reset it.
2. Keep them clean. Dust and debris can interfere with their operation, so vacuum over and around your smoke alarm regularly.

What if the alarm goes off while I'm cooking?

Then it's doing its job. Do not disable your smoke alarm if it alarms due to cooking or other non-fire causes. You may not remember to put the batteries back in the alarm after cooking. Instead, clear the air by waving a towel near the alarm, leaving the batteries in place. The alarm may have to be moved to a new location.

How long will my smoke alarm last?

About eight-to-ten years, after which it should be replaced. Like most electrical devices, smoke alarms wear out. You may want to write the purchase date with a marker on the inside of your unit. That way, you'll know when to replace it. Always follow the manufacturer's instructions for replacement.

Anything else I should know?

Some smoke alarms are considered to be "hard wired." This means they are connected to the household electrical system and may or may not have battery back-up. It's important to test every smoke alarm monthly. And always use new batteries when replacing old ones.

Smoke (Detectors) Alarms PDF