Gas leaks are uncommon, but they are one of the most serious household emergencies. Knowing the signs and responding correctly can save lives.
Warning signs of a gas leak
**Smell.** Natural gas is odourless in its natural state, but gas suppliers add mercaptan — a sulphurous compound — to give it a distinctive rotten egg or hydrogen sulphide smell. If you smell this in your home, treat it as a leak immediately.
**Hissing sound.** A gas pipe or appliance connection under pressure may produce an audible hiss near the source of the leak.
**Dead plants.** If house plants near a gas pipe suddenly wilt and die without explanation, leaking gas in the soil around the roots may be responsible.
**Physical symptoms.** Gas inhalation can cause headaches, dizziness, nausea, and disorientation. If multiple people in the house experience similar symptoms simultaneously, consider a gas leak.
**Bubbles in wet ground.** A leak from underground supply pipes can cause bubbling in wet soil or puddles in the garden near the gas meter.
**Yellow or orange flame.** Appliances burning gas with a yellow or orange flame (rather than crisp blue) may indicate incomplete combustion related to supply pressure or appliance fault.
What to do immediately
1. **Don't use any switches.** Don't turn lights or appliances on or off. Any electrical spark can ignite gas.
2. **Don't use your phone inside.** Take your mobile phone outside before calling.
3. **Open doors and windows.** Ventilate the property as you leave.
4. **Turn off the gas at the meter.** The emergency control valve is next to the meter — turn the handle 90° so it's perpendicular to the pipe.
5. **Leave the property immediately.** Get everyone (including pets) out.
6. **Call the National Gas Emergency Service: 0800 111 999.** Free, 24/7.
Do not re-enter the property
Do not return until the National Gas Emergency Service has attended, confirmed the leak is repaired, and declared the property safe.
After the emergency
Once the property has been cleared as safe, contact a Gas Safe compliant engineer to inspect all appliances and pipework before gas is restored to normal use.
NBS Plumbing & Heating — Gas Safe compliant — **07507 133204**.