It is compounds of Mercury that are the most environmentally dangerous. The pure metal itself is non-toxic. How many children have bitten thermometers and swallowed a glob over the years? The metal needs to be in ionic form to be toxic, Mercuric Iodide - very nasty, the chloride also bad, the vapour deadly. Of course the metal will certainly undergo chemical reactions in the soil, or dump, or wherever it happens to end up and so it is not a good idea to have it lying around. In a bio lab for example; if mercury gets between the cracks in lab benches, or the floor, it can slowly vaporize and minute amounts in the atmosphere can cause real trouble to people trying to grow microbes or animal cells in culture. But this is the exception - not the case. The metal usually has a protective coating of oxide and dirt that keeps it from evaporating at a dangerous rate. I'm talking about a few parts per billion by the way. That's why its not a good idea to try to use a lab that has been used for physical chemistry for microbiology. Its been tried.
Don _______________ Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: March 30, 2002 ----- Original Message ----- From: "Keith Whaley" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, February 21, 2003 2:25 PM Subject: Re: *ist complete specifications > I don't think any manufacturer in the U.S. has made any mercury filled > thermometers for quite a while. It's probably an Environmental > Protection Agency thing. > That may well slop over to any other industrial product, such as > mercury switches. > Thing is, once mercury gets into the environment, it doesn't readily > combine with other elements and become in innocuous chemical. It stays nasty... > > I've been out of the business for quite a while, so I don't know how > inventive they have become for replacing mercury switches. Seems that > would be a bit difficult! > > keith whaley > > Rob Studdert wrote: > > > > > I don't think so, mercury switches are probably banned here in North America. > > > North of the Rio Grande at least. > > > > Mercury thermometers too? > > > > Rob Studdert > > HURSTVILLE AUSTRALIA >
