What is Carbon Monoxide?

  • Carbon Monoxide is a very poisonous gas. You also might also see it written down as CO, which is its chemical symbol.
  • It is created when fossil fuels like gas, oil, wood, petrol, and coal burn 'incompletely'. This means when they burn without enough oxygen or air supply.
  • You can’t see it, smell it, hear it, or taste it – that’s why it’s known as the ‘silent killer’.
  • Carbon Monoxide doesn’t only come from gas appliances. Any appliance that uses carbon as fuel can produce it. This includes oil-fired appliances, log fires, coal fires or even charcoal barbeques.


Symptoms of Carbon Monoxide Poisoning

Carbon Monoxide is very poisonous, so breathing it in can make us very sick and can even be fatal.

Symptoms of Carbon Monoxide poisoning include:

  • Headaches
  • Dizziness
  • Nausea
  • Breathlessness
  • Collapse
  • Unconsciousness

If you suspect you or someone else may have Carbon Monoxide poisoning, please seek out medical help immediately.

What to do if you think there is Carbon Monoxide?

If you or someone is experiencing symptoms, or if your Carbon Monoxide alarm is going off, please follow the steps below:

  • Open windows and doors to help get fresh air into your home
  • Move everyone in the home outside into the fresh air
  • Call the gas emergency number 0800 111 999 or use textphone 0800 371 787
  • If anyone is showing symptoms, seek out medical help immediately.


Only if it is safe to do so:

  • Turn off your gas meter
  • Extinguish any solid fuel appliances
  • Turn off your oil or LPG supply


How can I avoid Carbon Monoxide?

The best way to reduce the risk of Carbon Monoxide is to have an alarm and get your appliances checked regularly.

Remember that Carbon Monoxide is very poisonous, but you can’t see, smell, hear, or taste. So, if there was a Carbon Monoxide leak you wouldn’t be able to tell.

1.    Getting an Alarm

The alarm can detect Carbon Monoxide, even at low levels. The early warning will mean you aren’t breathing it in without knowing. So, it can keep you safe before you would see any symptoms.

Carbon Monoxide can seep through walls, so can get into your home from a neighbour’s home. So, it's important to have an alarm in case Carbon Monoxide is coming in from outside your home.

You can get an alarm in most DIY shops and can order them online. We recommend getting one that makes a sound when it detects Carbon Monoxide.

It’s important to test your alarm regularly and check it is still within its expiry date, the batteries aren’t empty, and the alarm is working properly.

The alarms are quite small and portable. This means you can take it with you to keep you safe if you are travelling or staying away from home.

 2.    Getting your appliances checked

If you have carbon fuelled appliances get them checked and serviced annually by a qualified engineer. Here is a list of what to look for:

  • Gas Engineers – Gas Safe Registered
  • Oil Engineers – OFTEC Registered
  • Solid Fuel Engineers – HETAS Registered


You can also keep an eye out in between checks, for any signs your appliance might be creating Carbon Monoxide. This can include:

  • Staining on appliance casing or surrounding walls/decoration
  • Yellow floppy flames (with the exception of flame effect fires)
  • Soot deposits
  • Excess condensation in a room when an appliance is in operation
  • General poor condition of appliances, such as visible damage or poor function

If you suspect your appliance might be producing Carbon Monoxide, call an engineer straight away. Please follow our step above if you think there in Carbon Monoxide in you home