If you suspect you may be affected by carbon monoxide poisoning

If you're experiencing any of the symptoms of carbon monoxide (CO) poisoning, seek urgent medical advice from either your GP or an A&E department and ask for a blood and/or breath test to confirm the presence of carbon monoxide.

A senior male consulting with his doctor

When you breathe in CO it mixes with the haemoglobin in your blood stream to create carboxyhaemoglobin. A carboxyhaemoglobin level of 30% or more is considered to be a high level of exposure and cause for treatment. It’s important to do this quickly after the suspected exposure because carbon monoxide leaves the blood rapidly and tests to identify the presence of CO may not be accurate more than four hours after exposure.

If you have been exposed to high levels of carbon monoxide, you’ll be treated using standard oxygen therapy. This is when you receive 100% oxygen through a mask (normal air is about 21%) to help your body to quickly replace the carboxyhaemoglobin. Although mild carbon monoxide poisoning may not need hospital treatment, it’s always advisable to seek medical advice.

What to do if you think there is a carbon monoxide leak

If you suspect a carbon monoxide leak in your home, in the same way as if there was a fire, you should leave your property immediately. If you’re able to safely leave windows and doors open as you leave then do so. Once in the fresh air, call the gas emergency number on 0800 111 999 to let them know you have a suspected carbon monoxide leak. They will arrive with the proper equipment to deal with the problem. Under no circumstances should you return to your home until you’re told it’s safe to do so.

  • Switch off the appliance (find out more about potential carbon monoxide sources) and do not turn it back on until you’re told it’s safe by a Gas Safe registered engineer
  • If you can, shut off the gas supply at the meter control valve. If carbon monoxide gas continues to escape call National Grid on the Gas Emergency Freephone Number 0800 111 999
  • Open all doors and windows to ventilate the room. Do not sleep in it
  • Visit your GP urgently and tell them that you believe your symptoms may be related to carbon monoxide poisoning. Your GP should advise a blood and/or breath sample be taken

Contact our Home Services Team on 0800 980 2122 to arrange for one of our Gas Safe registered engineers to visit (service available in most areas of Great Britain). We may monitor and/or record calls for security, quality or training purposes. Calling us on an 0800 number should be free from all landlines and generally free from mobiles.

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