On 20/04/2019 16:24, NY wrote:
"Steve Walker" wrote in message
...
Leaks (within reason) are not too bad (except in an unventilated
garage) as unlike petrol vapour or lpg, it rises and dissipates rapidly.

I was thinking also in the sense of not wanting to find that your car
has less fuel than it had the previous day. As you say, H2 gas won't
hang around for long - it will rise and dissipate.

They do lose it, but it is reasonably slow from what I remember.
Presumably the isolating valve would be right on the tank for safety and
that would also minimise leak paths when parked up.

SteveW