Fuels take oxygen from the air when they burn. Gas, oil, wood, coal, petrol, and diesel all need an adequate supply of air to burn safely. If there is enough air, each carbon atom in the fuel links up with two oxygen atoms and makes carbon dioxide, CO2. If air is restricted, the carbon atom only gets one oxygen atom. It makes carbon monoxide, CO.
Carbon monoxide can join up with oxygen to make the less harmful carbon dioxide – if there is enough oxygen available. If there is not enough fresh air to supply oxygen, the carbon monoxide stays around. Typically this happens when a heating appliance is faulty, or has a blocked flue. CO from a faulty fire, boiler or furnace builds up in the home and causes poisoning leading to ill-health and even to death.
How CO Harms People
Blood has a red pigment, haemoglobin, which carries oxygen. Haemoglobin combines with oxygen in the lungs. It travels round the body. It releases oxygen where the body needs it. Unfortunately, carbon monoxide can combine with haemoglobin. It blocks the haemoglobin from picking up any more oxygen. The body is starved of the oxygen it needs.
Signs of CO Poisoning
- headache, tiredness
- nausea, vomiting
- dizziness, confusion,
- unconsciousness and death
The early symptoms are a bit like flu or tummy upsets. If everyone in the room is affected at the same time, suspect CO poisoning rather than flu. Cats and dogs may become unwell too.
How Can You Tell if There is CO Present?
- It is difficult because CO has no taste, smell or colour.
- Suspect CO if heating appliances burn with a yellow flame rather than a blue flame.
- Soot build-up on a gas fire, or soot streaks round a flue, is a sign it is giving off CO.
- Install a CO detector. In the EU it should meet the standard EN 50291. CO detectors sound an alarm if the gas is present. Latest detectors have digital readout in parts per million, showing even low levels of CO before it builds up enough to be deadly.
Avoiding Carbon Monoxide – fuelled by bottled gas
- Have boilers, furnaces and fires installed by an engineer with nationally recognised qualifications. (In the UK, Gas Safe Register for gas, HETAS for solid fuel and biomass, OFTEC for oil and liquid biofuel)
- Appliances that use fuel need annual inspection and service. Include the flue or chimney. They can become blocked or corroded.
- Between annual inspections, watch for flames that start to burn yellow instead of blue, and for soot appearing.
- Cabinet heaters fuelled by bottled gas, and also free-standing oil heaters, need to be in a well ventilated room i.e. at least one window open. They are not a good type of heating for permanent use but get used during cuts in electricity supply.
- Barbecues fuelled by bottled gas or charcoal, patio heaters, camping stoves, charcoal burners and chimeneas are designed for outdoors. They should never be used in a confined space like a garage, tent or marquee.
- Car, truck and motorbike engines, generators, outboard motors, motor mowers or cultivators, should only be run out of doors. Running them in a garage allows CO to build up even if the door is open.
- Be vigilant in holiday accommodation. Apartments or caravans may have substandard water heaters or gas fires. Keep a window open while using gas appliances. If you have a battery powered CO detector, take it on holiday (take out the batteries while travelling).
First Aid and Treatment
If you think you or family members have been poisoned by oxygen, get into fresh air straight away. Go to your doctor immediately, or call an ambulance if symptoms are severe.