A smell of gas: what to do, in order

This is the one where the order of the steps matters more than the steps themselves, and where the most natural instinct is the dangerous one.

A child walks into the kitchen and something smells wrong. A bit like rotten eggs, or garlic. Nobody is cooking.

Most safety advice is a list of things to do. This one is a list of things to do in a specific order, and getting the order wrong is what causes the harm.

The smell is engineering, not chemistry

Cooking gas has no natural smell whatsoever. You could fill a room with it and notice nothing.

The rotten-egg smell is a chemical called a mercaptan, added deliberately by the gas company in tiny quantities, for exactly one purpose: to turn a human nose into a leak detector. The safety system for the entire gas network is your sense of smell, and it was designed that way on purpose.

Which means noticing the smell is not the moment before the safety procedure. It is the first step of it.

The order

Air first. Open the windows and the door, so the concentration starts falling immediately. Then stop the source: turn the gas OFF at the cylinder or the main valve. Then call an adult. Then wait outside in the fresh air.

Air comes before the valve because ventilation starts working the instant you open a window, and because it protects you while you do everything else.

The thing that must not happen

No sparks. That is the whole danger.

Here is the part children (and adults) do not know: a light switch makes a tiny spark every time it moves. So does a fan switch, a doorbell, and the switch on an exhaust fan. In a room with gas in it, reaching for the light is one of the worst things you can do, and it is the most natural thing in the world to reach for.

So: no switches on, no switches off, nothing lit, no matches, no lighter. Open, turn the gas off, leave.

The answer

Show the answer

The order in the puzzle: notice → open windows and door → gas OFF at the cylinder or main valve → call an adult → wait outside.

The case is deliberately built so that several orders look sensible and only one is safe. Children usually want to turn the gas off first, which is reasonable but slower to help than simply opening a window.

Talking about it afterwards

And to take it further:

• "Why do you think they add a smell to something that does not smell?"
• "Which things in this room make a tiny spark when you touch them?"
• "If you smelled it at night, what would you do first?"

Worth rehearsing out loud once, in the actual kitchen, pointing at the actual valve. A procedure you have said aloud in the right room is one you can still find under stress.

Cases like this one

• Walking them across — the order is wrong
• The plant that was loved too much — the part is wrong
• The summer water bowl — the part is missing

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