Carbon Monoxide Awareness

Carbon monoxide (CO) poisoning can be fatal or cause permanent damage to your health.

CO is produced when carbon fuels don't burn completely.

It has no smell or taste and, in large quantities, it can kill very quickly.

How is carbon monoxide produced?

Carbon monoxide is hard to detect because it has no smell, taste or colour. This also means that it is easy to inhale without realising.

Carbon monoxide is produced when fuels such as gas, oil, coal and wood do not burn fully.

When a fire burns in an enclosed room, the oxygen in the room is gradually used up and replaced with carbon dioxide. Following a build-up of carbon dioxide in the air, the fuel is prevented from burning fully and it starts to release carbon monoxide.

Causes of carbon monoxide poisoning

Gas, oil, coal and wood are all fuel sources that are used in many household appliances, including:

  • boilers

  • gas fires

  • central heating systems

  • water heaters

  • cookers

  • open fires

If the fuel in these appliances does not burn fully, carbon monoxide (CO) gas is produced.

Other ways that carbon monoxide can build up

The build up of carbon monoxide can also be as a result of any of the following:

  • Indoor use of a barbecue grill or outdoor heater

  • Using cooking appliances for heating purposes

  • Enclosed or unventilated spaces - burning fuel in an enclosed or unventilated space, where there are no air vents, windows or doors left open or ajar

  • Faulty or damaged appliances - heating or cooking

  • Heating appliance not maintained or serviced

  • Badly ventilated rooms - sealed windows, no air bricks

  • Blocked chimneys or flues - birds nests, fallen bricks, growing vegetation, bad DIY

  • Poor or improper installation or use of appliances - such as cooking and heating devices

  • Running engines such as cars or lawnmowers in garages

  • Old appliances that have not been serviced or looked after properly

  • Paint fumes - Fumes from cleaning fluids and paint removers that contain methylene chloride (dichloromethane) can also cause CO poisoning

Danger signs

Danger signs that CO may be leaking include:

  • yellow or orange flames where there should normally be blue ones

  • sooty stains on the walls around fires and water heaters. You could also be poisoned by CO if you share a wall or chimney with a house that has a CO leak, even if your own house does not have one

Leaflets to download

Leaflet - Carbon Monoxide and camping (new window, PDF 1728KB)

Leaflet - Carbon monoxide and home safety (new window, PDF 1698KB)

Leaflet - who qualifies for checks? (new window, PDF 2090KB)

Story of a family who suffered from carbon monoxide poisoning (new window, PDF 3614KB)

Links to more information

Symptoms of carbon monoxide poisoning

Carbon monoxide facts

Carbon monoxide - what to do in an emergency

Preventing carbon monoxide poisoning

For further advice and support on gas safety and carbon monoxide visit Gas Safe Register (opens in new window)

Carry out your own home safety check

Complete our online home safety check and you will get a personalised fire safety plan, which will offer advice on how to prevent fires in your home.

Do the online home safety check

Book a home safety check

Cheshire Fire and Rescue Service will fit free smoke alarms for people who are aged over 65 and for people who are referred to us by partner agencies because they are considered to be at a particular risk.

If you are over 65 years of age and you live in Cheshire, you can arrange for a Firefighter or a Community Safety Advocate to visit your home for a free home safety visit. During the home safety visit advice will be given on how to make your home safer, what to do in the event of a fire and what to do if you are trapped by a fire. Free smoke alarms will also be fitted (if needed) with an explanation on how to maintain them correctly.

Book a home safety visit for over 65’s


Last updated: Monday 22 November 2021

Related images


Danger - carbon monoxide