> that in the real world those with experience seem to think the fears are
overblown, and I have not heard of anyone being harmed by OA the way I have
heard of many tales of harm from formic acid.

The key word is "harm."  As one with extensive experience with both oxalic
and formic acids, I can offer some more detailed comparison of
the practical risks of harm.

In the first place, no one is likely to consume, cutaneously absorb, or
inhale enough of either acid to cause body-level toxicity.

Formic is the more dangerous acid of the two.  With liquid formic, there
are the inevitable splashes , spills, and inhalation, meaning substantial
risk from splashing into your eyes or onto your body.  With
careless handling, there is a very probable risk of serious skin "burns"
(which may not be painful, but are really ugly as your skin peels off days
later, and then slowly regrows).  Impervious gloves (with your hands
pre-powdered with baking soda are clearly called for, and perhaps an
impervious apron and face mask.  Any spills onto your skin must be
immediately rinsed, or preferably neutralized with  a strong  (10 heaping
Tbl per gallon) solution of baking soda (sodium bicarbonate) in water.

As far as harm from inhalation, formic vapors or kinda self-regulating,
since the lining of your trachea feels them immediately, and cuts off
inhalation of that breath.  One can however, get nose bleed if one persists
in inhaling milder fumes.  When handling formic for any extended period of
time, an acid vapor mask or respirator is a good idea.
Bottom line for formic: risk is far higher with liquid formic acid; but
relatively low with MAQS or Formic Pro if used outdoors during a slight
breeze.

Oxalic acid is not nearly as reactive, and I've yet to see any sort of skin
burn.  After several to many minutes, you might notice a little irritation
if a concentrated solution gets on your skin, but it is easily rinsed off
and quickly neutralized with baking soda solution.

Keep in mind that any OA liquid or crystal residues are still acidic, and
don't just "go away" (as does formic by evaporating).  Residues of OA will
remain for a long time on clothing, door handles, hive tools, etc.  We keep
a jug of baking soda solution on hand to wipe everything down -- it's easy
to see the frothing where there were acid residues.

A splash of OA dribble into your eye, based upon two reports, is painful,
but can be rinsed out without serious damage.

When handling OA crystals, the crystals require first being dissolved in
water or sweat before they will burn your skin, and are not immediately
reactive on dry skin.  But you REALLY want to avoid having any crystals get
into your eye.

The cloud of OA microcrystals resulting from vaporization, are in my
experience, more painful than formic fumes, since it takes longer for your
trachea to feel the burn, resulting in deep inhalation into your lungs
before you feel the pain.

After using OA in all application methods, the safest (based upon my
experience) is the extended-release (OAE) with the 1:1 OA:gly, weight to
weight formulation (higher glycerin proportions are messier to handle).
Dribble would be second, then spray, with vaporization being the most
likely to cause a painful coughing fit.

Unfortunately, the OAE application method is not yet approved in the U.S.,
so I am not suggesting that anyone use it until it is.

Randy Oliver
Grass Valley, CA
530 277 4450
ScientificBeekeeping.com


>

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html