Subject: Re: Methane Gas poisoning/fried eggs
From: mannj@southern.co.nz (Jay Mann)
Date: Sep 16 1995
Newsgroups: sci.med

Bret and Jill Wood (jwood@teleport.com) wrote
>  One of the reasons that methyl mercaptan was chosen as the oderant for
>  natural gas is because it is one of the strongest smelling chemical
>  compounds known to man. If you were to spill 1/10 of a ml (about 1
>  drop) of methyl mercaptan in your home, the smell would be strong
>  enough to make it uninhabitable for quite a while, while it aired out.
>  Mercaptan

I was a student at the University of Wisconsin biochemistry department in 
the 1950's.  One winter's day, a senior professor decided to have a 
cleanout of his lab. There were sundry old bottles of mercaptans that had 
been used as experimental chemicals by students now graduated.  So Prof 
Johnson tipped them all, one by one, into a handy sink, and ran a bit of 
water on top.  What he forgot was that the drain lines of the entire 
building were interconnected.  There were small sinks in every office, 
for some historic reason.  Now, every sink has a small u-trap in the 
pipe, which when filled with water is intended to prevent smells from 
coming back up.  But many of these sinks had not been used for years, and 
the U-traps were dry.  So the mercaptan fumes filled the entire building.

Result: the fastest building evacuation ever recorded.  We all rushed out 
into the frigid Wisconsin winter weather without even bothering to put on 
coats.  From memory, someone volunteered to re-enter the building while 
wearing a gas mask, then he or she ran water into every sink in every 
room.  We were able to go back in after a couple of hours.

Jay D Mann  <mannj@southern.co.nz>
Christchurch, New Zealand