Purchased a portable generator recently? You need to make sure your home has working carbon monoxide alarms. Any equipment that runs on an internal combustion engine, including generators, lawn mowers, power washers, and cars, can unleash this colorless, odorless, and highly poisonous gas into your home.

Known as the silent killer, CO claims about 500 lives each year. About 170 of these deaths involve non-automotive products, including fuel-burning furnaces, gas ranges, and room heaters. Spurred by the weather-related demand for portable generators, engine-powered equipment has become an increasing threat. In 2005, for example, 47 people died from generator-related CO poisonings in the aftermath of Hurricane Katrina, according to the Consumer Product Safety Commission. Hurricane Sandy added at least a dozen deaths.

That's why it's critical to operate a power generator outdoors only, at least 15 feet from the house. But you also need to install CO alarms in your home. Consumer Reports' CO and smoke alarm buying guide tells you everything you need to know about choosing and using these devices. Our Ratings and recommendations include models from First Alert and Kiddie.