While the points made by Tim, Dan, and Garrett may have been valid
positions for beekeepers a few years ago, they illustrate the danger of
blithely applying "experience" to apparently similar, but new and very
different substances.

All chemicals are not created equal.  Claiming that experience with
herbicides, antibiotics, and other types of pesticides prepares one for
things like Checkmite is like claiming that ownership of a kitten qualifies
one to be a circus lion tamer.

The key word here is "organophosphate".  Coumaphos ("Checkmite") is
an organophosphate.

Organophosphates are neurotoxins.  They attack the nervous systems
of mites.  They can do the same thing to beekeepers.  Organophosphates
are so hazardous that the EPA says something that they have never said
about any other pesticide.  They admit that there IS no safe way to handle
this class of chemicals.

They are readily absorbed through the skin, but there is no type of glove
that can protect you.  The stuff goes right through all available types
of protective gear.  The effects of these toxins are cumulative, and
even very tiny "doses" can build up to levels that cause serious nerve
damage.

Do a search of Bee-L's archives for the term "organophosphate" at
http://listserv.albany.edu:8080/cgi-bin/wa?S1=bee-l&D=0, and read
what has been said by beekeepers and researchers who have looked
closely at this class of chemicals.  Note that organophosphates got
their start as "nerve gas", and only later were attempts made to sell
them to agricultural markets as pesticides.

Then read this page from U. Minn:

http://www.extension.umn.edu/projects/mpiap/fqpa/workop.htm

...and note that the beekeeper (the one expected to "handle" the
chemical) is the one taking the biggest risk.

        "Even with maximum feasible protective clothing
        and engineering controls, calculated risks for most
        OP [organophosphate] workers and handlers still
        exceed the Agency's level of concern. EPA believes
        that an across-the-board increase in risk mitigation
        measures is needed to protect occupational users
        of the OPs."

I am not saying that we should abandon all chemicals.  I myself
enjoy many aspects of "better living through chemistry", starting
every morning when I button a 60/40 cotton/poly shirt.

But one must draw the line somewhere, and a wise person draws
the line at the point where even the EPA says that "risks exceed
the Agency's level of concern".  This phrase is very rarely used.

Keywords to use when searching the web for relevant
information would be:

   cholinesterase inhibition
   organophosphate cumulative assessment
   organophosphate EPA

The rest of agriculture realized that organophosphates were a very
bad idea years ago.  The emergency Section 18s for Checkmite were
a desperate stop-gap measure, but no responsible person would ever
consider even suggesting that these chemicals be approved for long-term use.
This alone should be adequate warning to the beekeeper.

        jim