Hissing vapours

[lazyitus]

Returned from a nice spin out today and parked up in the garage as normal.

When I got out, I could hear a hissing sound and located it coming from the petrol filler cap area.

Undid the cap and released a load of vapour.

Is this normal as I've never had this before?

[HRG]

It's a heat thing. Could be the carbon can needs a clean but the heat certainly affects the fuel system.

[lazyitus]

So, essentially nothing to worry about ?