From: Joe Smigiel (jsmigiel@kvcc.edu)
Date: 02/22/03-08:02:27 PM Z
I've been doing darkroom work for thirty years, consider myself a safe and knowledgable worker, and yet don't know the answer to this one: Is Glacial Acetic Acid (or 28% for that matter) a "strong acid" with respect to potassium ferricyanide reactions. Is it possible to generate lethal hydrogen cyanide gas by mixing glacial acetic acid into potassium ferricyanide crystals? Anyone is able to walk into photo stores, buy a pound of potassium ferricyanide and a gallon of glacial acetic acid, no questions asked. Am I correct in respecting this combination as potentially hazardous, maybe lethal? Perhaps one of the chemists on the list could provide an informed answer...
Several toner formulas call for both ingredients in very dilute solutions. But, I see it as a possible (though unlikely) scenario that an inexperienced worker could mix the pure acid with the crystals. Anyone storing them together? I keep them far apart.
Glacial by itself is quite dangerous. Is there any good reason for it to be sold in photo shops?
How many darkroom workers have had formal training in a chemistry lab where safe practice is stressed and proper techniques demonstrated? How does the darkroom novice and "the photographer wishing to engage in potentially dangerous
processes" even know some things can be dangerous if we don't tell them at the outset? I'm appalled sometimes at the lack of knowledge photographers with many years experience have with regard to the chemistry of photography or general housekeeping in the darkroom. A general FAQ posted each week to this list outlining potential chemical dangers of our processes and methods seems a reasonable way to inform newbies and the curious.
I think Gord's idea is quite valid and I welcome it.
Joe
>>> liam.lawless@blueyonder.co.uk 02/22/03 19:19 PM >>>
PS: Seriously, you might want some disclaimers in the list of risks, just
in
case someone decides to eat a bowl of Jell-O they have laced with dichromate
or something and then decides to sue alt photo for not having mentioned the
dangers of doing so.
Precisely. Does the photographer wishing to engage in potentially dangerous
processes not also bear some responsibility to inform him/herself, at least
of the obvious or common dangers? Can an author not assume at least that
much common sense in his/her readers, or should ALL relevant safety
precautions be contained in EVERY published article on photographic
processes? They all carry some risk - you could choke on hypo crystals, you
know.
Bear in mind also that to obtain mercury, cyanide, strong acid, etc., these
days, a buyer also has to satisfy the seller of his/her competence to handle
it, if it can be obtained at all. Such substances are therefore unlikely to
fall into the hands of the inexperienced or totally incompetent.
Liam
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