Why is Carbon Monoxide Dangerous

Though you can neither see it, smell it nor taste it, carbon monoxide (CO) is an extremely poisonous gas. In fact, over 50 people die from CO poisoning each year in the UK.

Carbon monoxide is a by-product of the incomplete combustion of carbon-based fuels, like coal. Since energy is released when a fuel reacts with oxygen, in order to perform most efficiently, a fossil fuel must have a rich air supply. When the fuel is burned with sufficient oxygen complete combustion will occur, producing carbon dioxide and water. However, when a hydrocarbon fuel is burned with only a limited air supply, incomplete combustion will occur, producing carbon (in the form of soot), water and toxic carbon monoxide gas.

Carbon monoxide poisoning

How CO can interfere with the blood’s ability to deliver oxygen to the body’s vital organs

1. Air inhaled into lungs – When clean air is inhaled into the lungs oxygen enters the bloodstream by combining with a substance called haemoglobin, which is found in red blood cells. If the air contains a lot of carbon monoxide, however, oxygen can’t enter the blood.

2. CO displaces oxygen in blood – This happens because carbon monoxide is far better than oxygen at combining with haemoglobin, so when CO is present in the lungs the blood cells choose to absorb it over oxygen, preventing the latter from entering the bloodstream and travelling to all the body’s tissues that need it.

3. Vital organs deprived of oxygen – With the bloodstream full of carbon monoxide instead of oxygen, the blood carries CO to the body’s tissues/organs starving them of oxygen (known as hypoxia). Major organs like the heart and brain are most susceptible to CO poisoning.