Carbon monoxide (CO) is colorless and odorless. If you have an alarm, evacuate the structure and call 911. Read the manufacturer's documentation for maintenance and know the indications of a low battery.
As of July 1, 2011, the Carbon Monoxide Poisoning Prevention Act (Senate Bill-SB183) will require all single-family homes with an attached garage or a fossil fuel source to install carbon monoxide alarms within the home by July 1, 2011. Owners of multi-family leased or rental dwellings, such as apartment buildings, had until January1, 2013, to comply with the law. See the following document for additional information on Carbon Monoxide:
Frequently Asked Questions (FAQ) on Carbon