Re: Mercury spills

[Stan Dodds <dodds@RICE.EDU>]

Odd this should come up just as I have been cleaning out an old
lab. Quite a bit of liquid mercury under the wooden floor boards, as
it turns out, although air tests a number of years ago did not
indicate significant levels in the room.

Puddles of mercury can be sucked up with a homemade vacuum arrangement
consisting of a flask with some water in the bottorm, a water
aspirator to pull a modest vacuum and some plastic tubing to suck up
the spill and transfer it to the flask. The mercury and probably the
pick-up tube can then be disposed of.

The sulfur trick works well on small, dispersed droplets, although you
should allow a day or so for the reaction to complete. Our safety
people use a proprietary product called Hg Absorb (Lab Safety Supply,
800-356-0783). It is a metal powder that rapidly forms an amalgam with
the mercury. The resulting solid is easy to pick up for
disposal. Having used both, I find the metal product a bit better. The
reaction is faster and it is easier to get enough on the mercury to
react completely (sulfur is pretty fluffy).

Using a regular vacuum cleaner is probably a bad idea because it is
unlikely to pick up the dense material effectively and it may disperse
what it does gather. Incidentally, the Illinois story has the marks of
an urban legend. Most homes are so well ventilated that vapor from
modest spills of dirty mercury is not likely to reach hazardous
levels.

Hope this helps.

Stan



> The discussion regarding the repair and maintenance of mercury
> barometers is very interesting, and the discussion regarding safe
> handling of mercury is especially so.
>
> What is the best method to clean up spilled mercury?  A chemist
> suggested to me that I sprinkle powdered sulfur over the spilled
> mercury.  The sulfur and mercury react to form mercurous sulfide which
> can be swept up with a broom.  Does anyone else have any other ideas?
>
> One method NOT to use is a vacuum cleaner.  Believe it or not, several
> years ago a homeowner in Illinois tried to clean up spilled mercury
> using the household vacuum cleaner.  Mercury vapors were blown out the
> exhaust contaminating the house.  Illinois EPA was eventually called
> in.  The house had to be demolished.
>
> Thanks.
>
> Glenn A. Carlson, P.E.
> St. Charles County Community College
> St. Charles, MO
> gcarlson@mail.win.org