Carbon monoxide

Carbon monoxide (CO) is a -

  • colourless
  • odourless
  • tasteless
  • poisonous gas

produced by incomplete burning of carbon-based fuels, including-

  • gas
  • oil
  • wood
  • coal

Carbon based fuels are safe to use. It is only when the fuel does not burn properly that excess CO is produced, which is poisonous. When CO enters the body, it prevents the blood from bringing oxygen to

  • cells
  • tissues
  • organs

You can't -

  • see it
  • taste it
  • smell it

but CO can kill quickly without warning.

According to health and safety England statistics every year around seven people die of CO poisoning caused by gas appliances and flues that have not been properly installed, maintained or that are poorly ventilated.

Levels that do not kill can cause serious harm to health if breathed in over a long period. In extreme cases paralysis and brain damage can be caused because of prolonged exposure to CO. Increasing public understanding of risks of CO poisoning and taking sensible precautions could dramatically reduce this risk.

There are signs that you can look out for which indicate incomplete combustion is occurring and may result in the production of CO -

  • yellow or orange rather than blue flames (except fuel effect fires or flueless appliances which display this colour flame)
  • soot or yellow/brown staining around or on appliances 
  • pilot lights that frequently blow out
  • increased condensation inside windows

People suffering from carbon monoxide poisoning should get fresh air immediately, open doors and windows, turn off gas appliances or extinguish other sources, leave the house, and see a doctor.

There are a few simple steps that gas consumers can take to keep themselves safe.

Carbon monoxide can be produced by any combustion appliance, including those that burn fossil fuels for example, oil, wood, and coal. If you have one of these appliances, you should make sure that it is serviced and maintained by a competent person and the chimney is regularly swept.

Carbon monoxide alarms

CO alarms protect residents by giving an early warning when the poisonous gas is detected in the home. Installing an alarm is a simple task, with most detectors only requiring a couple of screws, while some are free standing and require no installation.

Ideally the alarms should be installed next to potential sources of CO in the premises and in sleeping areas. The alarms should be at a horizontal distance of between 1 and 3 metres from the potential source and at least 1.5 metres from the ceiling if fitted on a wall. Avoid putting them too close to windows or air vents.