(Cuezilla) writes:

That is an old tale that is often repeated. I have even seen in
print. MOP is made of around 85% calcium carbonate, (Same stuff in a
Rolaids), 12% conchiolin,(A protien that acts as a binder) and 3%
water, none of which are harmful or poisonous.

(rest deleted)

OK, not poisonous like rat poison or cyanide, but dangerous to work with
nonetheless. Consider the dust that flakes off this stuff: look at it
under a microscope, and you'll see little jagged spicules. Once they're
in your lungs, they don't ever dissolve, or break down and get carried
away - they just sit there and get scar tissue built up around them.
Think asbestos from abalone.

The bottom line: don't breathe the dust. It's bad juju.

MOP and abalone shell get used a lot in lutherie, the art of instrument
building. There are a bunch of lutherie sites with info on the dangers of
MOP and how to contain them.

Alden

--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."