my mate's dad
was a freight-forwarder and would often go onboard ships with manifests and cargo lists and things to sign. One particular cargo was drums and drums of a chemical called Ethyl Mercaptan. That's the stuff that they put in natural gas.

The drums were sealed, but bear in mind that the human nose can detect the smell as low as 1 part in 3 billion parts air and make you go "Arghh! Gas leak", the smell was overpowering and he smelt of the stuff for a week afterwards. Having to keep telling people that they most likely don't have a gas-leak and it was him.
( sandettie light vessel automatic New Twitter - @bollocksreally, Tue 18 Nov 2008, 16:00, Reply)