In article ,
"Paul C" writes:

Methane is odourless so they add a 'smelly'. I think the additive is Ethyl
Mercaptan (Ethanethiol) and its a ridiculously low concentration as that
stuff is so smelly. When I worked in a lab years ago, someone threw 5
millilitres down a sink and the building had to be evacuated due to the
nauseous affect of the pong. Neighbours around the site were phoning British
Gas reporting smell of gas.

Imperial College in the early 1980's, or did someone else do that too?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]