Carbon monoxide (CO) is a toxic gas produced by the incomplete combustion of fossil fuels including gas, oil, wood and coal used in boilers, engines, oil burners, gas fires, water heaters, gas ovens, solid fuel appliances and open fires.
It can occur when a gas appliance has been incorrectly fitted, badly repaired or poorly maintained. It can also occur if flues, chimneys or vents are blocked.
It is colourless, odourless and tasteless, so the best way to detect carbon monoxide is to fit a CO alarm.
The most common symptoms of mild carbon monoxide poisoning are headache, nausea and feeling tired or confused - in fact, very similar symptoms to those of flu.
However, if you find your symptoms improve or go away when you are away from home, and get worse when you return, and if everyone else in the home, including pets, has the same symptoms, you may be experiencing carbon monoxide poisoning and should see your GP immediately.
In severe cases, it can quickly cause collapse and loss of consciousness, long term damage and even death.
For you and your family's safety, it is advisable to fit a carbon monoxide alarm in each room in your home that has a gas appliance.
The Gas Safe Register recommends the use of an audible carbon monoxide alarm rather than one that just changes colour when carbon monoxide is present. It is important that it will alert you straight away or wake you up if you are asleep. The alarm should be marked with British Standard EN 50291, and a British or European approval mark such as the Kitemark.