Re: paper test data for palladium

John Rudiak (wizard@laplaza.taos.nm.us)
Fri, 9 Feb 1996 15:44:53 -0700 (MST)

When discussing the toxicity of chemicals in the platinum/palladium
process, don't forget that the oxalates are all poisonous, and there's
alot of it in the oxalate/dichromate developer. Merk lists the toxicity
of sodium dichromate as equal to chromium trioxide (chromic acid) which
is used medically in a 5% solution as a topical antiseptic. Potassium
oxalate is just listed as poisonous.

Be especially careful when mixing the ferric oxalate solution from the
powder. I wear a mask and add it to the water in a different room than my
darkroom, the dust is particularly nasty, and shouldn't come near
negatives or prints as it could bleach them. I had a selenium toned
silver print pinned to the wall above the drying cabinet I use to dry to
platinum paper after coating. After a year of printing and opening up
the cabinet to take the paper out, the silver print has become bleached
with only a pale, pinkish image left (I assume this is mostly selenium).

Hope this helps, be careful.

John Rudiak