What is carbon monoxide?

Carbon monoxide (CO) is a colourless, odourless and highly poisonous gas. Because you can't see, smell or taste it, it can be extremely dangerous if it builds up indoors.

CO is produced when fuels do not burn completely. Common sources include:

• Gas, oil and solid fuel appliances
• Wood-burning and multi-fuel stoves
• Open fires and coal fires
• Barbecues and charcoal
• Portable heaters and generators
• Petrol and diesel engines

The risk from correctly installed, well-maintained appliances is very low. However, faulty, poorly ventilated or incorrectly used appliances can produce dangerous levels of carbon monoxide.

Symptoms of carbon monoxide poisoning

Carbon monoxide reduces your body's ability to carry oxygen, which can quickly make you seriously ill.

Common symptoms include:

• Headache
• Dizziness
• Nausea or vomiting
• Tiredness or weakness
• Shortness of breath
• Confusion
• Loss of consciousness in severe cases

Long-term exposure to lower levels of carbon monoxide can also cause ongoing health problems and may be difficult to recognise.

Protect yourself

• Have fuel-burning appliances installed and serviced by a qualified engineer.
• Ensure chimneys and flues are cleaned and maintained.
• Never use barbecues or portable fuel-burning equipment indoors or in enclosed spaces.
• Fit a carbon monoxide alarm in rooms containing fuel-burning appliances and test it regularly.

If your carbon monoxide alarm sounds, or you suspect carbon monoxide poisoning, leave the building immediately, call the emergency services if anyone feels unwell, and do not re-enter until it has been declared safe.