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. 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.

The effects of breathing in carbon monoxide

When you breathe in carbon monoxide it enters your bloodstream. There it mixes with haemoglobin. Haemoglobin is the part of red blood cells that carries oxygen around your body. However, when carbon monoxide mixes with haemoglobin, the blood is no longer able to carry oxygen. The lack of oxygen causes the body’s tissue and cells to die.

When haemoglobin mixes with carbon monoxide it produces a compound called carboxyhaemoglobin. Carboxyhaemoglobin adversely 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.

Outlook

People with mild symptoms of carbon monoxide poisoning usually make a full recovery.

However, between 10 and 50% of people with serious CO poisoning can have long-term problems. Sometimes, complications can arise years later as a result of the CO gas causing damage to the heart.

Glossary

Oxygen

Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Tissue

Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.

Blood vessels

Blood vessels are the tubes in which blood travels to and from parts of the body. The three main types of blood vessels are veins, arteries and capillaries.

Brain

The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.