Smieglitz@aol.com
Date: 06/25/01-06:17:00 PM Z
In a message dated 06/25/2001 13:11:20:
<<have had a little dig around looking at cyanotype stuff and it does seem
like it could be the right thing.
my only question is regarding the health and safety issues with the chemistry
(no mention in the selection i've looked at). Not being very alt-processy
(right now) I dont know how much respect the chemicals for the formula
require, and cyanotype does sound a little scary.>>
Benedict,
The cyanotype chemistry is pretty benign according to the sources I've read.
In fact, it's probably one of the simplest and safest processes given many
people's sensitivity to metol and the other metals and chemicals used in so
many processes. The potassium ferricyanide *sounds* pretty deadly but isn't
a problem if handled correctly. It poses a danger if you were to expose the
crystalline form to strong UV radiation or dump some strong acid into the
crystals (or I suppose a very concentrated solution). Both of those
conditions would lead to the liberation of hydrogen cyanide gas which is
lethal. In the cyanotype process, those conditions aren't normally present
and the ferricyanide solution is weak, about 8% as I recall. Just don't put
the crystalline form under the UV box, in direct sun, or near any strong
acids. (Sodium or potassium cyanides used in some toners, bleaches,
intensifiers and other processes are quite a different story and can be quite
deadly. Better to avoid them altogether and find a different formula to do
the job.) You are probably in more danger mixing up a stop bath from
concentrated acetic acid solutions than you are with cyanotyping.
I've also heard one account of someone supposedly allergic to the process but
that seems a rare case if not unique exception. Maybe they were allergic to
the other component, ferric ammonium citrate. Best to consult a MSDS for
info though. I think a toxicity statement can also be found at
www.blueprintables.com. The folks there sell precoated cyanotype T-shirts,
fabrics and papers. You might also want to check Dr. Mike Wares' excellent
website and his cyanotype book.
In any event, read up on the chemicals before beginning to use them and
exercise good housekeeping and safety procedures with them. Cyanotypes are
pretty simple and can be a lot of fun. The process is a good intro into
alternative photography.
Joe
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