What is carbon monoxide (CO)?

Carbon monoxide (CO) gas has no smell, taste or colour and it kills dozens of people in their homes every year. Many more suffer debilitating illnesses often without anybody realising that they are being poisoned.

CO gas is produced by solid fuel, oil and gas (including LPG) fired heating appliances such as fires, boilers and water heaters. Any appliance which burns solid fuel, gas or oil and which does not have a balanced flue so that it is sealed off from the room is capable of poisoning you if it is not properly installed, maintained and serviced.

Recognising the signs of CO poisoning

The signs of CO poisoning are very like "flu". Typically they can include headaches, nausea, drowsiness, dizziness and vomiting. If you suffer these symptoms over a period of time, if several members of the family suffer the same or similar symptoms or if visitors to your home say that they feel ill when there but are ok when they get home then you should get your appliance checked.

It is important that all solid fuel, gas and oil burning appliances are serviced every year by a competent person. By law only people who are Gas Safe (formerly CORGI) or OFTEC registered are allowed to work on gas appliances and oil appliances respectively. All new installations must also comply with Building Regulations including solid fuel appliances. Please see our Building Control pages for information on Building Regulations.

There are few signs to indicate that carbon monoxide is building up inside a property, which is why regular checks and servicing are vital, but things to look out for are:

  • the flame on your cooker should be crisp and blue, Lazy yellow or orange flames mean you need to get your cooker checked
  • soot or yellow/brown staining around or on appliances
  • pilot lights frequently blow out
  • increased condensation inside windows

Safety precautions you should take

If you rent or let out a property or static mobile home for domestic or commercial use and it has gas appliances then annual gas safety checks must be carried out. A copy of the gas safety certificate must be provided to the tenant within 28 days of the annual check.

Chimneys should be swept every year by a competent person, ideally who is a member of the National Association of Chimney Sweeps or the Guild of Master Sweeps.

If you're worried about carbon monoxide poisoning, you may wish to purchase an audible CO detector. The detector is a bit like a smoke detector and will sound an alarm if the level of CO reaches a hazardous level. Detectors are available from major DIY stores and hardware shops as well as your energy supplier and usually cost less than £20. Before purchasing a CO alarm, always make sure it is officially approved to EN 50291. It must have a British or European approval mark on it, such as a BSI Kitemark™.

Where can I find out more?

For further advice or information contact your doctor, the contractor who maintains your appliances or contact us using our contact form for Environmental Health.

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