Carbon Monoxide (CO) can be fatal


Carbon monoxide (CO) is an odourless, colourless, non-irritant gas. It is the most common cause of fatal poisoning in Britain today. It causes the accidental deaths of up to 500 people each year in the USA and a much larger number of sub-lethal poisonings.  A secondary hazard of Carbon Monoxide gas is that it is highly flammable and explosive.

These figures could be just the tip of the iceberg as poisoning by carbon monoxide is almost certainly underdetected. There are two main reasons for this.

Firstly, there is generally little awareness of carbon monoxide poisoning among the general public and the medical profession.

Secondly, the signs and symptoms associated with carbon monoxide poisoning are not easy to diagnose as they often mimic many other conditions.

To overcome this deadly killer requires improved awareness among the public of the risks and dangers of carbon monoxide poisoning and increased vigilance on the part of healthcare professionals in its detection.

Children, pregnant women, babies, and individuals with a heart condition are those at most risk but CO poisoning can affect anyone.

Where does carbon monoxide come from?

Carbon monoxide is produced by the incomplete combustion of carbon-containing fuels, such as gas (domestic or bottled), coal, oil, coke and wood. Gas stoves, fires, heating boilers, gas-powered water heaters, paraffin heaters, and solid fuel-powered water heaters are all potential sources of carbon monoxide. The problem arises when such appliances are poorly maintained, not serviced and housed in poorly ventilated areas.

When the waste products of combustion are not effectively removed, for example because of blocked flues and chimneys, then poisonous gas mixtures may re-enter the room. This problem is not just associated with older or poorer homes; it can also affect the occupants of newer homes with gas central heating. Exhaust fumes from cars is another obvious source.

Domestic sources of carbon monoxide include:

  • domestic heating systems

  • blocked flues/chimneys

  • inadequate ventilation in living areas

  • inadequate ventilation in adjoining car garages

  • leakage from faulty appliances and chimneys/flues.

This highlights an important issue. Even with perfectly designed and maintained heating appliances (or any kind of combustion device), they too will eventually begin producing dangerous amounts of CO if used in confined and poorly ventilated areas. Having poorly operating appliances, only makes the problem worse more quickly. Maintaining appliances and ensuring sufficient fresh air is available are two easy ways of avoiding potentially lethal scenarios.

What are the symptoms of carbon monoxide poisoning?

One of the difficulties with diagnosing carbon monoxide poisoning is that many of its symptoms are similar to those of other conditions. Often the onset of symptoms is gradual, occurring without the individual or doctor being fully aware of what is happening. Coupled with this is the fact that the severity of the poisoning depends on:

  • how much carbon monoxide is actually present in the environment.

  • the duration you are exposed to carbon monoxide.

  • the age of the individual concerned - elderly, children and the foetus are all at greater risk.

  • the general state of health.

  • the extent of physical activity - effects are increased with higher activity levels.

The most common symptoms include:

  • headache

  • nausea and vomiting

  • vertigo

  • altering states of consciousness

  • weakness

Where such symptoms are reported repeatedly, domestic carbon monoxide poisoning should be suspected.

The HSE strongly recommends the use of audible carbon monoxide (CO) alarms as an important precaution but they must not be regarded as a substitute for proper installation and maintenance of gas appliances by a Gas Safe Registered engineer. Before purchasing a CO alarm, always ensure it complies with British Standard EN 50291 and carries a British or European approval mark, such as a Kitemark. CO alarms should be installed, checked and serviced in line with the manufacturer’s instructions.

Please note: You can be particularly at risk from CO poisoning when you are asleep, because you may not be aware of early CO symptoms until it is too late. Having an audible CO alarm could wake you and save your life.