search  current discussion  categories  techniques - painting 

k2cro4 -- use it, but don't lick the brush

updated sat 31 may 97


Vidreiro on tue 13 may 97

>> "brain database" here....... as I recall it, potassium
bichromate (dichromate) is, like all chromium compounds, a carcinogen.
It also causes skin ulceration and severe irritation to nasal
membranes. I think the OSHA airborn TLV's are the same as for lead
compounds....although not sure on that one. <<

O banco dos dados da cerebro esta furado ---

I'll point, again, to the fellow in the glass plant who made 2,500 lbs
of green glass with K2CrO4 every day for 35 years and who today is still
out chasing girls --- much to their chagrin. He didn't smoke, eat or put
the material on his Wheaties. He handled more "bichromate" in a day than
most anyone here will in their career using the most rudimentary
cautions. Remember, for most of his career there was no Hysteria over
chemicals and the measures taken to keep the materials out of the
organism were simple common sense -- don't eat it, smoke around it or
kick-up a lot of dust. Pretty basic.

Hexavalent chromium (it's yellow alone or that great orange as a
compound) is not the sort of thing you'd want to put on your Wheaties.
However, if it is put in aqueous (water) solution and used for a wash on
a pot it can create lovely watercolor type effects and should not be
excluded from the palette of options. Don't drink the solution, don't
lick the brush, don't smoke or eat while handling the material or its
solution and you'll die anyway, but probably from something else.

Tri-valent chrome -- Cr2O3 -- it extremely stable material. Anyone who's
tried to melt it into a glaze knows that. Although you may notice that
the glaze is kind of yellowish -- that is owing to a bit of hexavalent

If you read an MSDS on the material you'd think you're handling death
itself. Yet here, as with Barium and

KPP --