The safest form of gas leak is when it has ignited .
We worked on that principle in the steelworks.
We used vast amounts of ultra pure hydrogen gas as the atmosphere in razor strip annealing furnaces. The steel does not tarnish in an hydrogen atmosphere.
For that purpose it is ideal as it does not react with the red-hot steel and is also a remarkably good conductor of heat.
The snag is that it is "very" explosive over a wide range of mixtures with air.
We had large cabinets with pressure regulators, flowmeters, and control valves.
In each cabinet was kept burning a small natural gas flame.
The principle was that in the event of an hydrogen escape it ignited the hydrogen before it had chance to build up.
Of course retorts filled with large quantities of hydrogen gas at around 1050 degrees centigrade are a disaster waiting to happen anyway.
I've always lived dangerously, I must have a guardian angel 'cos I'm still here.