Re: smoke sticks? -Reply

["Thomas J. Shelley" <tjs1@cornell.edu>]

>Wes,
>
>In other contexts, I have used a Drager product to
>generate "smoke".  I can't recall much detail about the
>product, except that it was a tube enclosing s glass vial
>which is broken, resulting in combination of reagents which
>results in the generation of smoke.

Mark and Wes,

These are called "air current tubes" and they generate a fine
spray of sulfuric acid mist which, being a very hygroscopic
agent, immediately forms a fog in moist air.  They are good
for visualizing air flow on a small scale such as inflow into
a fume hood, etc.  The hazards associated with their use are
burns associated with any H2SO4 residue and the sharp, ragged
tips of the glass tubes after they are broken open.  Plastic
tubes filled with TiCl4 are also used for the same purpose.
Both, especially the TiCl4, can leave residues on the surfaces
and equipment in a fume hood and care must be exercised not
to contaminate experiments in progress in a fume hood during
their use.  Even though it is somewhat messy, I now prefer
the dry ice in water protocol.  The only hazard associated with
the dry ice is the fact that it is very cold and it must be
handled with cryogenic materials rated gloves to prevent
frostbite.  Good luck with your various projects.  Tom

*************************************************************

Tom Shelley,   Chemical Hygiene Officer, Cornell University,
Department of Environmental Health and Safety, 125 Humphreys Service Building,
Ithaca, NY 14853.       (607) 255-4288              tjs1@cornell.edu


************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html