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  1. #1
    ronlamarsh's Avatar
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    Potassium Dichromate Hazards?

    I was thinking about getting into carbon printing but after reading the MSDS on both types of dichromate sensitizer I was rather alarmed and turned off to the process. Thought's? My concern is the entire process from sensitizing to developing.......when does the dichromate disappear,if ever, and the print safe to handle with bare hands??????????
    No escaping it!
    I must step on fallen leaves
    to take this path

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    E76
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    As long as you follow the appropriate precautions, using dichromate is safe. If mixing from powder, handle it in a well ventilated area and wear gloves and a dust mask. Once dissolved in solution it becomes much easier to handle (no risk of inhalation), but you're obviously not going to want to make skin contact with it (so once again, wear gloves). The dichromate will disappear from the carbon print after it is washed, and a solution of sodium bisulfite (IIRC) will clear any remaining amount (at which point the print will be perfectly safe to handle with bare hands).

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    tiberiustibz's Avatar
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    If you constantly worry about impending death you'll have no fun in life. Go ahead and take some risks!

    Just don't eat it and wear gloves. When dealing with the powder wear a mask. The powdered form is generally most dangerous because you can inhale it.

  4. #4
    Andrew O'Neill's Avatar
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    No worries about potassium dichromate. Just wear rubber gloves. I use it as a contrasting agent for kallitype printing. By the way, I too will be getting into carbon printing. Ordered Sandy King's book and waiting for supplies to come in.

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    I am a carbon printer so my opinion may be biased. But in my opinion there is very little risk involved with dichromates in carbon printing. The major risks are ingestion (not likely that you would drink it) and breathing the powder when making a solution, which can be easily avoided. After the dichromate is in solution the risk is primarily dermatolgical, so you wear gloves.

    The dichromate is out of the print after warm water development and clearing with sodium bisulfite, or sodium or potassium metabisulfite.

    In practice you use very little dichromate in carbon printing. For example, to sensitize a 9X12 tissue I use only 8ml of a 10% ammonium dichromate solution. That is with brush sensitizing. Some people sensitizer in a tray and use more, but it is not necessary.

    Sandy King




    Quote Originally Posted by ronlamarsh View Post
    I was thinking about getting into carbon printing but after reading the MSDS on both types of dichromate sensitizer I was rather alarmed and turned off to the process. Thought's? My concern is the entire process from sensitizing to developing.......when does the dichromate disappear,if ever, and the print safe to handle with bare hands??????????

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    .....AND here in Denmark, we HAVE to get a police permit, just to get to buy it....



 

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