What to do if you smell gas

Act first, diagnose later. The steps below are in order and there is nothing to add to them.

The five steps

1. Turn off the cylinder valve. Close it fully, by hand.
2. Do not touch any electrical switch. Not a light, not a fan, not a phone charger. A switch makes a small spark whether it is going on or off.
3. Open the doors and windows. LPG is heavier than air, so open low openings as well as high ones.
4. Leave the area. Take everyone with you, including anyone asleep.
5. Call your supplier from outside the building, or a qualified gas fitter.

Why does the electrical switch matter so much?

Every switch arcs slightly as the contacts meet or part. In a room holding a gas and air mixture, that arc is an ignition source.

This includes turning something off. The instinct to switch off the light on the way out is the wrong one here.

Why open low windows and doors?

LPG is heavier than air. It sinks and pools at floor level rather than rising and dispersing through a high vent.

That single fact explains most LPG safety rules — why cylinders never go in basements, why floor-level ventilation matters, and why a leak can sit in a room that smells clear at head height.

When is it safe to go back in?

When the smell has gone completely and the room has been ventilated for a good while with the valve still closed. If any smell remains, do not re-enter — call a qualified gas fitter.

What if the smell is coming from outside your home?

Treat it the same way, and tell your neighbours. Do not go looking for the source with any kind of flame.