Cyanotype dangers - urgent

Discussion in 'Black and White' started by manuela_f, Mar 8, 2016.

  1. Hello everyone,
    I'm a young student from Paris, France, and today was my second time doing cyanotype prints at home. I have never taken any classes, just studying independently for my graphic design and photography studies.
    Today I was in a bit of a hurry, and I wasn't wearing gloves while handling the chemicals. One of the two liquid solutions, not sure which one because they are kept in two identical brown bottles, fell on my hand, which I promptly washed. I have no rash or anything like that, but I'm still concerned about any possible risk, even though I called the local anti-poisoning center where they told me it shouldn't be much of a problem. But much worse, I believe, I completely overlooked the danger of heating the solution of the two chemicals: I hairdryed my emulsion on the papers without the cool setting, in my small and windowless bathroom. And I used a UV lamp to make the exposures, again in a non aerated space. It was really stupid of me, I didn't do more than two cyanotypes, but still, I am wondering if, even though I have no symptom, I should seek medical attention to make sure everything is fine. I may be overly preoccupied now, but I know that heating the mix of potassium ferricyanide and ammonium iron citrate can produce highly toxic gas.
    I was wondering if any of you can share some experiences that could reassure me.
    Thanks a lot in advance,
  2. I don't want to appear unpleasant but if you have a fear
    of photographic chemicals, you should switch across to
    digital. Photographers have been using chemicals for
    over 150 years without problems. They are generally
    inherently safe. (Except ferricyanide) Study your
    chemistry *before* using them and take whatever
    appropriate steps are advised. Generally speaking,
    normal developing chemistry is never a problem unless
    you are being willfully stupid. If you are genuinely
    concerned, call an ambulance, never seek emergency
    advice from a forum. That is irresponsible.
  3. Thanks for your answer. I am usually very careful, today I have been a bit hurried and I did contact the anti-poison center in my city well before writing my message here. I came on this forum to have a confirmation on what the doctor told me on the phone; he wasn't concerned, but I don't believe these kind of centers usually receive many calls about such specific substances, and that's why I'm simply here to hear from others about their practice. For example, if someone answers here saying that they hairdry with hot air their cyanotype papers without ever having problems, I would have been reassured, that's all.
    I do not have any particular fear about photographic chemicals in general, I practice regular analog photography without any problem, but I am fairly new to cyanotype, which I am studying alone, so, having been for once a little less careful, I came here to read about other people's experiences.
  4. As a retired analytical chemist I'll say cyanotype is the safest photographic process. It is often used by school children in class. Warming cyanotype mixtures won't liberate hydrogen cyanide gas. "Ferricyanide" sounds like "cyanide" but they are very different. The first is safe the second is dangerous. There's plenty of chemical anxiety on the internet but I can't find a single authenticated case of harm to anyone, anywhere, anytime from routine use of the cyanotype process. "Safe" is a relative concept. Boiling water for a cup of tea or driving a car causes countless injuries.
  5. Is this the Maris Rusis who lived in Sunshine Beach?
  6. PS - I don't wish to appear argumentative but ferricyanide is actually extremely dangerous. Not in itself (low toxicity, agreed) but if any acid comes into contact with it, it releases hydrogen cyanide (ie Zyclon B, the poison that was used in gas chambers by the Nazis).
    Why would acid come into contact with ferricyanide, you may ask? - answer is that we photographers regularly use acetic acid as a developer arrester and I can see a situation where these two chemicals (ferricyanide and acetic acid) are accidentally mixed, with catastrophic results.
    Again, careful research, before using any chemicals ensures that no accidents will happen - and that's the bottom line.
  7. In the days of chemistry sets for children, ferricyanide was a popular chemical in such sets. (They seem to be hard to find these days.) I never heard of any problem with it in those sets.
    The reason ferrocyanide and ferricyanide are useful is that the CN bonds very tightly to the Fe. You need a very strong acid to get it out. A strong enough acid that it will cause your hands more problem than the HCN gas that comes out. Even at 100%, acetic acid is a fairly weak acid. Concentrated (laboratory grade) HCl or sulfuric acid would be more of a problem.
    Note that the reason that HCN is poisonous is that the CN again binds very tightly to Fe, specifically the Fe in you blood.
    Note that the cyanotype process is similar to the blueprints commonly used in industrial and architectural drawings. If it was a big problem there, you would know about it.
  8. No, don't worry. The chemicals are no more toxic than many other domestic chemicals. I've used them for years. Just rinse any splashes off your hands and you'll be OK. I don't bother wearing gloves for cyanotyping.
  9. I will tell you what, Anytime you work with chemicals at home you have to use caution. I make salt prints at home and I'm very good with cleaning stuff up, but one day, my kids ventured into my workshop and placed their little arms on the work surface, no worries here, all was cleaned up so no exposed chemicals plus I keep stuff locked up anyways. Next day, they play outside and my wife notices strange black spots on their arms. She's freaking out, so takes them to the doctor thinking it's an allergy to something. The doc puts on a mask and examines the spots - saying they they are on the surface so probably some kind of discoloration due to exposure to something. I come home and think hard about it. Do you know what it was? It was tiny specks of over sprayed 12% silver nitrate solution that when applying on paper with brush sprayed on the work surface and came in contact with their arms. They were then exposed to Sun's UV light and that exposed these tiny specks of silver nitrate. It's funny now, but we were both freaking out. Chemicals are as safe as you are.

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