Pyro toxicity?

Discussion in 'B&W: Film, Paper, Chemistry' started by SchwinnParamount, Jan 13, 2005.

  1. SchwinnParamount

    SchwinnParamount Subscriber

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    I read somewhere once that all of the pyro film developers out there are highly toxic and must be used with great care. I have young kids at home and no lock on my chemical cabinet. If I start working with a pyro developer, should I be any more vigilant than I am with XTOL?
     
  2. modafoto

    modafoto Subscriber

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  3. c6h6o3

    c6h6o3 Member

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    I've been using pyrogallol based developers since before my children were born. No more vigilance has ever been necessary with this chemical than is necessary with chlorine bleach or drain cleaner, both of which are far more accessible to the children than my photo chemicals.
     
  4. rusty71

    rusty71 Member

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    That's a good thread. I have read that Pyro is also a suspected carcinogen. It is a known mutagen, which indicates a very likely carcinogen. Honestly, I use Rodinal, and my theory is that if your ideas are bad, no magic elixir developer is going to make you a better photographer. But to each his/her own.
     
  5. Silverpixels5

    Silverpixels5 Member

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    Most anything is a carcinogen in sufficient doses. Good lab practices should keep you in the clear.
     
  6. mark

    mark Member

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    No, the cabinet should be 6 feet or more above the floor and locked.
     
  7. Jorge

    Jorge Inactive

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    The pyro toxicity myth is overblown, but it is better to be safe than sorry. If I had young children at home, regardless of my knowledge in chemistry I would have it under lock. The first thing a child will do when they find something is to try to taste it, clearly even if pyro was not toxic, it is not something you want them eating.
     
  8. rbarker

    rbarker Member

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    I think the answer to your question is, "A little, perhaps." But, if you read the references pointed to in the thread Morten mentioned, I think you, too, will come to the conclusion that the pyro-paranoia is substantially over-blown. Nitrile gloves are probably a good idea (to avoid trans-dermal absorbtion), but everyone should be using those when working with chemicals anyway.

    Should chemical cabinets be locked? Sure, just like household chemical cabinets, if there are small children about. But, naturally, don't leave the key abound where they can get to it. They watch, and figure all of these things out, ya know. Once they reach an age where they can really understand things, dissolving a piece of bologna in sulfuric acid in front of them as a warning about chemicals, and a mention of how much it hurts to be dissolved, usually does the trick. :wink:
     
  9. rusty71

    rusty71 Member

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    Actually, if my parents had shown me how to dissolve bologna in acid, I would've though "Cool! I'm gonna pick that lock!"
    Probably follwing normal safety procedures with Pyro will be adequate. There is a detailed article here: http://unblinkingeye.com/Articles/PCat/pcat.html

    Below is a quote from the article which bears on the original question:
    "Both Pyrogallol and Pyrocatechin are very toxic chemicals. However, the primary danger to photographers is dermal absorption and breathing the dry powder, both of which are easily avoided. Always use rubber gloves when processing sheet film in trays, and either go outdoors or use a vent hood to mix Pyrogallol or Pyrocatechin into solution. By following these simple procedures, and exercising common sense, the potential health risks associated with using these chemicals for developing film are virtually eliminated."

    I still like Rodinal though....
     
  10. SchwinnParamount

    SchwinnParamount Subscriber

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    The cabinet is actually quite a ways out of their reach. It is 5 feet above the floor and there are obstacles in front of it ( such as a locked darkroom door... most of the time) plus the kids know to stay away from the stuff. I was more concerned about an accidental spill or powder in the air that poisons the environment of my house.
     
  11. Aggie

    Aggie Member

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    LIke I said in the link that Morten provided to another thread, Pyrogallic acid is an ingredient used in medical topical ointments. To my knowledge they are still absorbed through the skin. You can do a google search and find this tidbit out for yourself. The only thing that you need to be careful of out of the ordinary precautions you take with any chemical is to be aware of the dry powdered form. It is harmful if inhaled in the dry state, for it goes directly from the lungs into the blood stream and thus crosses the blood brain barrier. I know no one here wants me to break that down further. Use common sense. You lock the cleansers and other household cleaners away from children, you do the same with ALL of you photography chemicals. Use gloves if you are paranoid. It also helps when you wear gloves to keep your fingernails from turning brown. If it spills in the powdered form, just be careful and try not to raise dust while you clean it up. You can spray it with a little water before you do the clean up that gets rid of the dust, and the problem of breathing it
    no more harmful in that state than the chlorine in cleansers. Relax and enjoy.
     
  12. Claire Senft

    Claire Senft Member

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    Pyro used to be a mainstay of developers and I have read that Edward Weston had blackened fingers from from tray developing sheet film in pyro with bare hands. I have also read conjectures that his Parkinson's disease may have been a result of regular and prolonged pryo contact.

    I can say unequivically that if you get a pyro based developer on your hands they will get blackened immediately especially with pyro in a viscous substance such as TEA.

    For myself, my opinion is to do your utmost to handle the chemicals with REASONABLE care and to KEEP THEM AWAY FROM CHILDREN AND LABEL THE CONTENTS OF YOUE BOTTLES SO THAT IF SOMEONE IS INJURED YOU OR ANYONE ELSE CALL TELL THE DOCTOR OR PARAMEDICS WHAT THEY WERE EXPOSED TO.

    I remember back in the 70's I was using a bleach component from C41 that came in GLASS bottles that had an extremely irritating smell with a horrible, caustic ,choking odor.

    I thought to myself that If I ever wanted to clear a room that breaking that bottle would be much more effective than tear gas.

    So, while I do not subscribe to the idea of chemicals being a terrible thing, I also believe that the current awareness has done some good.
     
  13. Canuck

    Canuck Member

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    From my perspective, using the liquid mix I have no problems with (normal care) but mixing it up from powder is not a good idea without a good fume hood of a chemistry lab.
     
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  15. Jeremy

    Jeremy Member

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    I thought the black fingernails came from Amidol and not the pyro and you are right about the Parkinson's--they are conjectures which have never had any sustained scientific research that I know of from all of my reading.

    Nevertheless, one should ALWAYS be careful with chemicals.
     
  16. k_jupiter

    k_jupiter Member

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    I use three developers, Rodinal, W2D2+, and Homebrew Panthermic 777. Any of them you want your kids swilling? Any of them you want repeated contact with your hands?

    Simple precautions, keeping them out of the way of my daughters, specific instructions to leave Daddy's stuff alone, and use of gloves if there is the chance of skin contact with the developers. Since most of my work is done in closed tanks, it isn't an issue.

    As far as dry chemicals, only the Panthermic 777 is a powder (well, a bunch of powders) and I have only had to make that up once so far. An hour in latex or nitril gloves once every 6 months isn't too bad an imposition for the look I like to get with that developer.

    Be careful, the rest will fall into place.


    tim in san jose
     
  17. c6h6o3

    c6h6o3 Member

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    The powder in the air is a problem. Always use a respirator when you mix pyrogallol, and I would always do it outside whenever I could. You really don't want to breathe pyrogallol.
     
  18. c6h6o3

    c6h6o3 Member

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    Be careful with that paraphenylene diamine. It's just as bad as pyro, if not worse.
     
  19. k_jupiter

    k_jupiter Member

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    Ahyup. I wore a dusk mask when I made that stuff up as well as latex gloves. Interesting enough paraphenylene diamine is an ingredient in many hair dyes. IF you spill a little 777 on your hands, you see why.

    tim in san jose
     
  20. Kirk Keyes

    Kirk Keyes Member

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    And how do we know Weston's Parkinson's was not from the Amidol? (Just trying to start an new, unsubstantiated rumour.)
     
  21. Claire Senft

    Claire Senft Member

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    You may be right.

    It might have been the amidol that blackened his fingers. However, I know from personal experience that the pyros will stain fingers as well as gelatin.
     
  22. rbarker

    rbarker Member

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    Actually, I thought philandering caused Parkinson's. :wink:
     
  23. Kirk Keyes

    Kirk Keyes Member

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    Well, there you go. I guess that question is solved!
     
  24. k_jupiter

    k_jupiter Member

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    I'm gonna go out this weekend and pull all them suckers up from my garden. I told her not to plant them.

    tim in san jose
     
  25. JackRosa

    JackRosa Member

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    I mix the pyro powder outside and wear gloves and a apron when developing with PMK. I like Rodinal very much but HP5+ and FP4+ negs developed in PMK have significantly less grain with gradation every bit as good as the one obtained with Rodinal.

    I produce unsharp masks from negs developed in PMK and the effects are just as good as with masks produced from negs developed in Rodinal. Howard Bond's procedure for developing masks (an excellent one indeed) is tricky with pyro-developed negs because the standard densitometer does not take into account the stain. I use a "color" densitormeter for that. Instead of trying to determine sandwich densities, I simply use the split-grade technique to print those sandwiches.

    If I was did contact printing, exclusively, I would probably use Rodinal exclusively (with HP5 and FP4). Mixing the powders is not fun; having two solutions (A,B) to contend with and, most importantly, the issue of cleaning right away .... pyro stains like there is no tomorrow! For ample enlargements, I think PMK would do a better job.
     
  26. Mateo

    Mateo Subscriber

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    I can retort unequivically and with first hand knowledge that pyro based developers do NOT stain your fingernails black. My fingernails are a lovely light brown hue that you wouldn't even notice. From time to time my fingernails are a near black purple color from using amidol in print developement. I would not recommend that anyone soak their hands in Pyro but neither would I recommend soaking their hands in anything with metol.

    Pyro is just not as bad as its reputation. Use common sense, keep it away from children and enjoy its great qualities.

    P.S. for those wanting proof that Mr. Weston's parkinson's disease was not related to pyro; would you care to offer proof that it wasn't the result of having walked in iceplant? Equally rediculous.