Carbon monoxide (CO)is a colourless and odourless compound produced by incomplete combustion from any flame-fueled device, including ranges, ovens, clothes dryers, furnaces, fireplaces, grills, space heatersand water heaters. Open flames, such as from ovens and ranges, are the most common source of carbon monoxide.

CO is often referred to as the "silent killer" because it is virtually undetectable without using detection technology.Elevated levels of CO can be dangerous to humans depending on the amount present and length of exposure. Smaller concentrations can be harmful over longer periods of time while increasing concentrations require diminishing exposure times to be harmful.

Callsafe Electrical provide mains-powered,linked CO Alarms to British Standard EN 50291.

You can be particularly at risk from CO poisoning when you are asleep, because you may not be aware of early CO symptoms until it is too late. Having an audible CO alarm could wake you and save your life.