Carbon monoxide poisoning – What are the
symptoms?
You can’t see it, taste it or smell it but it can kill quickly
and with no warning.

Unsafe gas appliances produce a highly poisonous gas called
carbon monoxide (CO). It can cause death as well as serious long
term health problems such as brain damage.
Remember the six main symptoms to look out for:
- headaches
- dizziness
- nausea
- breathlessness
- collapse
- loss of consciousness
Being aware of the symptoms could save your life.
Carbon monoxide symptoms are similar to flu, food poisoning, viral
infections and simply tiredness. That’s why it’s quite common for
people to mistake this very dangerous poisoning for something
else.
Other signs that could point to carbon monoxide poisoning:
- Your symptoms only occur when you are at home
- Your symptoms disappear or get better when you leave home and
come back when you return
- Others in your household are experiencing symptoms (including
your pets) and they appear at a similar time
What should I do if I experience any symptoms of carbon
monoxide poisoning?
- Get fresh air immediately. Open doors and windows, turn off gas
appliances and leave the house
- See your doctor immediately or go to hospital - let them know
that you suspect carbon monoxide poisoning. They can do a blood or
breath test to check
- If you think there is immediate danger, call the Gas
Emergency Helpline
- Get a Gas Safe registered engineer to inspect your gas
appliances and flues to see if there is a dangerous
problem
Don’t assume your gas appliances are safe: get a Gas Safe
registered gas engineer to do a check. This is the only safe way to
prevent yourself and those around you from incurring serious
illness or death due to carbon monoxide exposure.
What is carbon monoxide?
Carbon monoxide (CO) is a highly poisonous substance produced by
the incomplete burning of gas and Liquid Petroleum Gas (LPG).
This happens when a gas appliance has been incorrectly fitted,
badly repaired or poorly maintained. It can also occur if flues,
chimneys or vents are blocked.
Oil and solid fuels such as
coal, wood, petrol and oil can also produce carbon
monoxide.
What is carbon monoxide poisoning?
Carbon monoxide poisoning occurs when you breathe in even small
amounts of the gas.
When you breathe in carbon monoxide, it gets into your blood stream
and prevents your red blood cells from carrying oxygen. Without
oxygen, your body tissue and cells die.
Levels that do not kill can cause serious harm to health when
breathed in over a long period of time. Long term effects of carbon
monoxide poisoning include Paralysis and brain damage. Such long
term effects occur because many people are unaware of unsafe gas
appliances and subsequent gas leaks.
How do I avoid a carbon monoxide leak in my home?
Your home may show signs of carbon monoxide. Any one of the
following could be a sign that there is carbon monoxide in your
home.
- The flame on your cooker should be crisp and blue. Lazy yellow
or orange flames mean you need to get your cooker checked
- Dark staining around or on appliances
- Pilot lights that frequently blow out
- Increased condensation inside windows
If you have a faulty appliance in your home, it could lead to
carbon monoxide poisoning.
Get your gas
appliances checked to avoid carbon monoxide poisoning.
Why should I get a carbon monoxide alarm?
Because carbon monoxide has no taste, smell or colour. Gas Safe
Register strongly recommends you fit an
audible carbon monoxide alarm in your home.
While an alarm will alert you to carbon monoxide in your home, it
is no substitute for having an annual gas safety check and regular
servicing by a Gas Safe registered engineer.
A carbon monoxide alarm looks similar to a smoke alarm and is very
easy to fit by following the manufacturer’s instructions. You can
purchase a carbon monoxide alarm from £15 at your local DIY store,
supermarket or from your energy supplier.
Before purchasing a carbon monoxide alarm, always make sure it is
marked to EN 50291. It should also have the British Standards'
Kitemark or another European approval organisation's mark on
it. Follow the alarm manufacturer’s instructions on siting,
testing and replacing the alarm.
You are particularly at risk from carbon monoxide poisoning
while sleeping, as you may not be aware of early carbon
monoxide symptoms until it’s too late. Do not use the ‘black spot’
detectors that change colour when carbon monoxide is present. These
will not make a sound to wake you up if the poisonous gas is
present while you are sleeping.
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Fit a carbon monoxide alarm
An audible carbon monoxide alarm will alert you if there is carbon
monoxide in your home
Where can I get an alarm?