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  1. #11

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    The do's and dont's of disposal have nothing to do with safety and more to do with local environmental regulations. If you are a bussiness (as is the case of Bob) you are most likely SOL. You have to arrange for proper disposal. If you are a hobbiest, then you most likely fall under the household excemption. As others noted above selenium is a wonderful fertilizer in small quantities, but most importantly you have to remember that selenium toner has other ingredients like Ammonia and sulfur, also good for your plants.

    Selenium toner will last for years, so it can be used even after 2 years of storage. Ann's suggestion is a good one, with one modification, the print has to be exposed and developed and then placed in the toner to exhaust the selenium.

    In Holly's case, since this is an university, it is most likely that it is governed by environmental laws just as any bussiness. If so the two choices are to arrange for disposal (which most likely there is already a program in place, contact your chemistry department) or trying to exhaust the selenium and then dump the remaning solution. If it was me, I would try to avoid hassles and cover my ass and would contact the chemistry deparment and would ask them what are they doing with their chemical waste, I am sure they already have a program in place for disposal and most likely will take the jug of selenium toner off your hands.

  2. #12

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    Selenium is already 'in' the environment. Dumping a little bit down the drain does NOTHING to the environment.

    http://www.ext.colostate.edu/pubs/natres/06109.html

  3. #13
    Ole
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    Quote Originally Posted by avandesande
    Selenium is already 'in' the environment. Dumping a little bit down the drain does NOTHING to the environment.

    http://www.ext.colostate.edu/pubs/natres/06109.html
    Selenium is already in the environment, and is a necessary trace mineral. So are cobalt, molybdenum, copper, arsen, and just about every other element. Like all other trace nutrients, selenium is poisonous in high concentrations. If you look a bit more closely at the link provided, it deals with ppm and ppb of selenium, not per cent. Confusing these terms can be very, very dangerous.

    It's not a question of how much you dump, but how well you disperse it.
    -- Ole Tjugen, Luddite Elitist
    Norway

  4. #14

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    The average family puts 500,000 # of water down the drain each year. If you dump a pound of selenium(that is a LOT of toner) down the drain that is 2ppm. Probably only 1 in 1,000 people have a darkroom in their house. I stand by my statement about a darkroom (at least a home one) not effecting the environment. I am not confused by PPM.

  5. #15
    Ole
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    Quote Originally Posted by avandesande
    The average family puts 500,000 # of water down the drain each year. If you dump a pound of selenium(that is a LOT of toner) down the drain that is 2ppm. ...
    Provided you dump it gradually over the full year.

    I'm not saying you shouldn't pour selenium toner down the drain, I'm just saying you should think about where it's going and how it gets there.

    There are still lots of houses where waste water goes to infiltration in the ground, or through (small) local septic tanks. I wouldn't say that selenium is "harmless" in any of those cases.

    But with large central sewage treatment plants, or even unprocessed to sea, it won't do (much) harm.
    -- Ole Tjugen, Luddite Elitist
    Norway

  6. #16

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    from kodaks papers...

    Note: Observe the precautionary information on all
    chemical packages. The active ingredient in Rapid Selenium
    Toner is a sulfite salt that has a concentration of less than 2
    percent. Working solutions of the toner generally contain
    less than 1⁄2 percent selenium sulfite. These selenium
    concentrations are not considered hazardous when you
    handle the solutions under normal conditions. However, we
    recommend that you use print tongs and wear clean rubber
    gloves when you use this toner. If toner splashes onto your
    skin, wash immediately with plenty of water.
    If the prints you plan to tone are already dried, rewet them by
    immersing them in a fixing bath, and then rewash them.
    Otherwise, staining may occur.


    So your working solution is already down to 200ppm(roughly corrected by MW). As it is exhausted I am sure that it is much less than that. So your tray has 50ppm when you dump it down the drain.

    Ole is correct in stating that each situation is different and it should be handled with respect. I just hate the blanket statements that we are killing the environment when we dump spent toner down the drain.

  7. #17
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    Two points:

    First, I never mix fresh selenium toner. As my toner gets exhausted I just keep adding concentrate as necessary. About once every six months I drip the solution through a paper coffee filter. This method has worked fine for me so far.

    Second, regarding pouring spent toner down the drain. Comparing the ppm of the toner that one (or several) home darkroom workers pour down the drain as a part of the overall waste that's put down the drain by the entire community over a year is, at best, an unrealistic way to determine the impact you'll have when you dump your toner. The question you should ask is: Will pouring a given volume of toner at a given concentration down the drain cause a problem for my local sewage treatment facility or with my personal sewage system (i.e., septic system)? Unless someone here is a specialist in one of these fields, I think we should leave the determination of the impact to the experts. But you can always avoid the problem by just continuously replenishing your toner.
    Film is cheap. Opportunities are priceless.

  8. #18
    ann
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    i am not sure where the "blanket statement that we are killin the environment" is coming from, i must have gotten lost in the comments.

    I know i did not say that, what i said was i didn't think it was such a good thing to do, and this is based on the situation i am in with a teaching environment.

    I made the decison to deplet the selenium by placing prints in the tray and letting themd sit for a week; the amounts we are using are not the norm that one person would have in a small 1 person darkroom.

  9. #19

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    ann, what then do you do with the selenium-impregnated prints? If it goes in the garbage and into the landfill, doesn't it still get into the environment eventually?

    I just dump my spent selenium toner down the drain, but if your method is really better, I'll start doing it that way. Or dump it on my rose bushes. I use so little of it, though, that it may not make a difference one way or the other.

  10. #20

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    At the end of the day, if some people take a very cautious approach that cannot be a bad thing......

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