plea to chemists

For the first time since I started teaching Experimental Photography, Safety
and Risk Management has more or less told me today that I can no longer
teach the mordancage process because of the chance of toxic gas, etc.

I have talked with 6 different chemists over the last three weeks about
whether toxic gas is released with the process. None of them have said so.
But Safety and Risk Management does.

I am NOT pouring glacial acetic acid directly on copper chloride. Here is
the formula:

Into 750 ml water pour 80ml glacial acetic acid.
Add 30g copper chloride and stir.
Add water to 1000ml..

At time of use, this "Part A" is mixed in equal amounts with 20v hydrogen
peroxide. The print is submerged in this for a few minutes, rinsed (but not
always well) and then redeveloped into developer or toner, such as thiourea
or sepia.

The last person I talked to said that in the dilution I am using, the acetic
acid will reduce the copper chloride to a salt, not a toxic gas (e.g.
chlorine).

What do you chemists think?? Jon Bailey, Judy Siegel, etc., you've taught
this process before; what do you know?

The students are very unhappy at this turn of events, as you can imagine.
But I would not want to teach something that has this kind of danger to
students, either. So I really need to know the bottom line here...and it is
frustrating that there is conflicting information between chemists and
Safety and Risk Management. That said, SRM is the final word, so I would
have to convince them they are wrong.

I just don't have any close chemist friends short of this list :)
Thanks in advance,
Chris
Received on Thu Nov 10 19:48:15 2005