CPSC recommends consumers replace the batteries in their smoke and CO alarms annually and test the alarms monthly. Smoke alarms should be on every level of the home, outside sleeping areas and inside each bedroom. CO alarms should be installed on each level of the home and outside sleeping areas. CO alarms should not be installed in attics or basements unless they include a sleeping area. Combination smoke and CO alarms are available to consumers.
• Full list of CO Safety Guides