Immediately replace any smoke and CO alarms in your home that do not bear a Canadian certification mark, and replace them with ones that do, such as CSA, cUL, ULC or cETL. Dispose of the products according to the waste requirements for electronic products in your municipality. When purchasing a smoke or CO alarm, make sure the device bears a recognized Canadian certification mark directly on the product, not just the packaging. Follow the manufacturer's directions for installation, maintenance, testing and replacement of the alarm. Familiarize yourself with the instruction manual and the features of your alarm to ensure you can hear and recognize the sound of the alarm. Remember to test your alarms regularly, and for battery-powered products, follow the manufacturer's instructions for battery replacement. Find more information on Health Canada's website about smoke and CO alarms and fire safety in your home , CO poisoning , and buying consumer products online .