What To Do in a Gas Emergency

If a gas appliance has been badly fitted or poorly serviced, potential risks include gas leaks, fires, explosions and carbon monoxide (CO) poisoning. Here’s what to do if you smell gas or suspect it’s CO poisoning.

Article sections

  1. What to do if you smell gas
  2. Who to call in a gas emergency
  3. Gas leak FAQs

What to do if you smell gas

It’s crucial to act quickly in a gas emergency. These are the steps you need to take to stay safe:

  • Get fresh air immediately; make sure you open all doors and windows to ventilate the area.
  • Turn off the gas emergency control valve (also called gas emergency shut off valve) at the meter, unless the meter is located in a basement or cellar or at the LPG bulk tank or storage vessels.
  • Extinguish all naked flames and don’t smoke.
  • Don’t operate electrical switches (including turning light switches on or off) because this can ignite escaping gas.
  • Contact the relevant National Gas Emergency service number for your area. We’ve listed these numbers in the next section.
  • If the attending emergency operative identifies an issue with any gas appliances, follow their advice concerning the use of the equipment. Where advised, contact a Gas Safe registered engineer to fix the appliance and check it’s safe.
  • If you’re feeling unwell, visit your GP or hospital immediately and let them know you may have been exposed to carbon monoxide.
  • Don’t turn the gas supply on again until it’s been checked by a Gas Safe registered engineer.

Who to call in a gas emergency

If you smell gas, want to report a gas leak or require gas emergency services, there’s a free, 24-hour National Gas Emergency Helpline you can call.

The gas emergency number you need depends on where in the UK you’re based and the type of gas that’s involved:

Country Natural Gas (NG) Liquified Petroleum Gas (LPG) Towns Gas/Mains Gas**
England, Wales and Scotland 0800 111 999 Contact number on bulk storage vessel or meter* N/A
Northern Ireland 0800 002 001 Contact number on bulk storage vessel or meter* N/A
Isle of Man 0808 1624 444 0808 1624 444 0808 1624 444
Guernsey N/A 01481 749000 01481 749000
Jersey N/A 01534 755555 01534 755555


*This applies for bulk and metered supplies. For cylinder supplies, please check your local telephone directory for contact details. On caravan sites and boats, the site owner or boat operator may also have gas safety responsibilities.

**Guernsey and Jersey use a manufactured LPG/air mixture that’s commonly known as ‘mains gas’ and supplied from an underground main system. The Isle of Man has a similar system known as ‘towns gas’, but many of the installations on this system are being converted to burn natural gas.

Frequently asked questions


What symptoms could a gas leak cause?

One of the first indicators of a gas leak is often the smell, however there are some physical symptoms that may be experienced.

The most common symptoms include:

  • Feeling lightheaded
  • Nausea
  • Dizziness
  • Headaches

If you suspect a gas leak and have any of the above symptoms, please go outside into fresh air immediately and call the appropriate gas emergency helpline.

Stick men representing the six key signs of Carbon Monoxide Poisoning.

What does a gas leak smell like?

Gas is odourless in nature however the addition of mercaptan, a non-toxic and harmless artificial smell, helps to give it a unique smell to enable detection. Mercaptan gives off a strong sulphur-like smell which can be mistaken for the smell of rotten eggs. It’s often this smell that is the early warning of any sort of gas leak and you should take the appropriate measures to ensure the safety of yourself and others around you.

It should also be noted that carbon monoxide (CO) can also be leaked from gas appliances. This gas is a by-product of unsafe functioning gas appliances and has no smell. You’ll need a carbon monoxide or CO detector which will sound an alarm if CO is present. Learn more about CO and the dangers it poses.

Who can check for a gas leak?

Although anyone can check for a gas leak by way of the smell it gives off or, in the case of carbon monoxide, a CO detector activates – any confirmation and gas work should be completed by a competent Gas Safe registered engineer.


Find a Gas Safe registered engineer near you


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