Carbon monoxide poisoning

Carbon monoxide (CO) gas is produced by the incomplete burning of fuel. It is poisonous, and even breathing in a small amount can cause loss of consciousness and death. In the UK, more than 50 people die from accidental carbon monoxide poisoning every year, and 200 people are seriously injured.

How is carbon monoxide produced?

Carbon monoxide is hard to detect because it has no smell, taste or colour. It is therefore easy to inhale it 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 starts releasing carbon monoxide instead.

The effects of breathing in carbon monoxide

When carbon monoxide is breathed in, it gets into the blood stream where it mixes with the haemoglobin. Haemoglobin is the part of the red blood cells that carry oxygen around the body. When carbon monoxide mixes with haemoglobin, the blood is no longer able to carry oxygen. This lack of oxygen causes the body tissue and cells to die.

When haemoglobin mixes with carbon monoxide it produces a compound called carboxyhaemoglobin. Carboxyhaemoglobin affects blood vessels in the body, causing them to become 'leaky'. This can lead to swelling in the brain, causing unconsciousness and neurological (nerve) damage.