Carbon monoxide is a colorless and odorless gas, but that makes it all the more dangerous. The Centers for Disease Control and Prevention reports that 430 people die and 50,000 are hospitalized annually due to carbon monoxide poisoning -- primarily in household settings. You're probably aware of where to put smoke detectors and the importance of fire safety. But carbon monoxide detectors are as critical to you and your family's safety.

Here's everything you need to know about where to put them and how to use them.

Where should you place CO detectors?

If you're not sure of where to install CO detectors, you're not alone. Carbon monoxide detectors aren't as common as smoke alarms, leaving many people guessing on where to place them. The Consumer Product Safety Commission says proper carbon monoxide detector placement is "on each level of the home and outside sleeping areas."

For more specific spots, it's important to understand how carbon monoxide works. It's produced by flame sources or fuel-burning machines such as fireplaces, furnaces, gas driers, water heaters and vehicles. The gas is a slightly lighter than air and will rise, which can lead to carbon monoxide poisoning. 

The best place for a CO detector is on a wall roughly five feet from the floor, where it can measure the air at a height that people in the house are breathing it. A reasonable alternative is placing the detector on the ceiling and six inches from the wall. Here are the best places to install CO detectors by room. 

In the kitchen

The key to placing a CO detector in the kitchen is to avoid mounting it near or over a flame-producing appliance such as a stove, grill or fireplace. To avoid false alarms, install a detector 5 to 20 feet away from a fire source. 

Outside bedrooms

As mentioned, the CPSC recommends at least one carbon monoxide detector on each level of a home, outside sleeping areas. The recommendation is based on having a minimum number of detectors. Putting one in the hall allows all bedrooms to hear the warning if CO gas is detected -- which is particularly important as the symptoms of carbon monoxide poisoning are often mild enough that they won't wake you.

If you have multiple detectors, it's a good idea to install them in bedrooms as well. 

Basements and more

The International Association of Fire Chiefs recommends a CO detector in the basement since laundry machines, water heaters and furnaces are all potential sources of carbon monoxide -- and are often kept in the basement. In addition, installing a CO detector in the room or space over an attached garage is a good idea, as vehicles are one of the most common CO producers.

How to install carbon monoxide detectors

To install, follow the instructions that came with your CO detector. Here are the general steps, with a few tips.

1. Try to keep installations at least six feet away from a flame or fuel source to avoid false alarms. You can mount the device on the wall at least 5 feet from the ground, or on the ceiling six inches from the wall. Some devices plug directly into an outlet.

2. Trace and drill holes and hang the mounting bracket.

3. Be sure to use fresh batteries.

4. Test the device by pressing and holding the test button. You should see lights as well as hear an alarm. 

5. Attach the CO detector to the mounting bracket.

CO alarm maintenance

Smoke and CO alarms both need regular maintenance to operate properly. To maintain a CO alarm, start by pressing the device's test button to check its battery level. Even if the device works, you should replace the batteries at least once a year. 

Should carbon monoxide detectors be replaced?

CO detectors have a limited life span. Unlike smoke detectors that make a chirpy, warning sound when the battery is low, CO detectors start chirping when it's time to replace them. Plan to replace your CO alarms every five years. 

Types of carbon monoxide detectors

There are three main types of carbon monoxide detectors available. To choose the type that works best for your home, learn more about each type. 

Smoke/CO dual detectors: Some detectors are all-in-one, able to detect smoke and CO gas. They're best for space-challenged homes or areas where you want to reduce visual clutter. Many smart detectors are a combination. They are capable of notifying you of either event. 

Battery-operated CO detectors: Battery CO detectors are the easiest and most flexible type to install. They use sensor technology that reacts to extended CO gas exposure. You can mount the device anywhere and even move it, since it doesn't rely on a fixed power source. However, you'll need to change batteries once per year to ensure the detector has enough energy to operate properly for another 12 months.

Hardwired or plug-in CO detectors: Detectors that can be wired to an existing household current -- or plugged into an outlet -- are low maintenance because they don't need batteries. The sensor cycles itself to purge and resample for carbon monoxide.

What to do if your CO detector goes off

If your sensor goes off, you'll need to act quickly. Having a home safety plan that covers what to do in case of an emergency could be a lifesaver. Not all events that cause the CO detector to sound off require calling 911. A good first step is to check on everyone in the house to find out if anyone has symptoms similar to having the flu such as nausea, dizziness or a headache.

If one or more individuals are feeling sick, evacuate your home to avoid extended exposure to CO gas. Make sure that everyone who is affected goes outside to breathe in fresh air and call 911. If no one is feeling sick, you can contact the fire department or a certified technician to investigate the possibility of a problem. Ventilate the rooms, reset the alarm and turn off gas-burning appliances, waiting outside or at a neighbor's house if possible while you seek guidance from specialists.

Read more about home safety on CNET:

9 devices you should buy to make your home instantly safer
The hows and whys of monitoring air quality in the home
Fire safety guide: How to prevent fires and prepare for emergencies