Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,871   Posts: 1,583,414   Online: 1147
      
Page 4 of 4 FirstFirst 1234
Results 31 to 39 of 39
  1. #31
    hortense's Avatar
    Join Date
    Jun 2004
    Location
    Riverside, CA
    Shooter
    Large Format
    Posts
    612
    Images
    5

  2. #32
    Aggie's Avatar
    Join Date
    Jan 2003
    Location
    So. Utah
    Shooter
    Multi Format
    Posts
    4,925
    Images
    6
    lets see for a guy the guidelines are a minimun of 70 micrograms to max of 400 micrograms. Now correct me but isn't 400 micrograms equal to 4 mg. If that is the case, the 1:15 working solution had less than that in it. It's late and I do not have my chem book near.
    Non Digital Diva

  3. #33
    Ole
    Ole is offline
    Ole's Avatar
    Join Date
    Sep 2002
    Location
    Bergen, Norway
    Shooter
    Large Format
    Posts
    9,282
    Blog Entries
    1
    Images
    31
    No Aggie, 400 micrograms is 0.4 mg. A factor of ten can make a difference.
    -- Ole Tjugen, Luddite Elitist
    Norway

  4. #34
    KenM's Avatar
    Join Date
    Apr 2003
    Location
    Calgary, Alberta
    Shooter
    4x5 Format
    Posts
    800
    Quote Originally Posted by Aggie
    It's the same thing. Check it out! Selnium is one of the trace mineral we do not get enough of.
    Yes, Se is something we need in our diet. However, do NOT confuse dietary selenium with the selenium in toner. While they are both Se, it's pretty difficult to inhale a tablet into your lungs; once the liquid from KRST evaporate, you're left with Se dust which can be, depending on purity, extremely toxic.
    Cheers!

    -klm.

  5. #35
    Donald Qualls's Avatar
    Join Date
    Jan 2005
    Location
    North Carolina, USA (transplanted from Seattle)
    Shooter
    Multi Format
    Posts
    1,845
    Quote Originally Posted by Aggie
    It's the same thing. Check it out! Selnium is one of the trace mineral we do not get enough of.
    Yes, it's the same selenium.

    However, check the labeling on a supplement that contains it -- the Recommended Daily Allowance for selenium (for adults, presumably based on something like 70 kg body mass) is 67 micrograms. As little as two or three times the RDA can be significantly toxic. And 67 micrograms of elemental selenium is a speck that would be almost invisible to the naked eye in a good light (even if your eyes are younger than mine and still accommodate for close vision easily).

    In the Northwestern USA, Washington state, there's a wildflower called "Camas" that native Americans used as a winter food stock -- the root stores starch, similar to a potato (only much smaller). Problem is, the very same species is poisonous in some locations, and not in others -- the natives knew which meadows had which kind, but the white settlers didn't, and occasionally ate some of the "Death Camas" by mistake (the flowers, white on the safe plants and purple on the deadly ones, aren't visible in winter when the roots are dug for food). The difference? The purple ones are colored by selenium they've concentrated from the soil where it's available...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  6. #36

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by KenM
    Yes, Se is something we need in our diet. However, do NOT confuse dietary selenium with the selenium in toner. While they are both Se, it's pretty difficult to inhale a tablet into your lungs; once the liquid from KRST evaporate, you're left with Se dust which can be, depending on purity, extremely toxic.
    Yes, and don't confuse Selenium in toner with sodium selenite - the actual compound that the selenium is in, in the toner. None the less, sodium selenite is pretty toxic orally - around 5 mg sodium selenite per kg of subject body weight for rats, mouse, and rabbit was a lethal dose in 50% of the test subjects. Assuming the same toxicity for people, that would be about .3 g total oral dose for a 70 kg human... So don't ingest any. See http://www.jtbaker.com/msds/englishhtml/s4946.htm for more info.

    But the trick to cleaning up this spill is to keep the work area wet - use a mop and wash the area thoroughly several times. If you see any residue when it starts to dry, wash it again several times.

    I would not use Aggie's suggestion to wash the area with acetic acid - a simple wash with lots of fresh water should suffice. After the area has dried, if you are still concerned, seal off the area of the spill by repainting the area or replacing the flooring, but that may not need to done with a thorough water wash.

    You should probably wash your shoes and the clothing that you were wearing while cleaning up the spill, to remove any contamination from them. After all, why clean up the spill on the floor and then track it back into the house, where you actually live...

  7. #37
    Aggie's Avatar
    Join Date
    Jan 2003
    Location
    So. Utah
    Shooter
    Multi Format
    Posts
    4,925
    Images
    6
    Quote Originally Posted by Donald Qualls
    Yes, it's the same selenium.

    However, check the labeling on a supplement that contains it -- the Recommended Daily Allowance for selenium (for adults, presumably based on something like 70 kg body mass) is 67 micrograms. As little as two or three times the RDA can be significantly toxic. And 67 micrograms of elemental selenium is a speck that would be almost invisible to the naked eye in a good light (even if your eyes are younger than mine and still accommodate for close vision easily).

    In the Northwestern USA, Washington state, there's a wildflower called "Camas" that native Americans used as a winter food stock -- the root stores starch, similar to a potato (only much smaller). Problem is, the very same species is poisonous in some locations, and not in others -- the natives knew which meadows had which kind, but the white settlers didn't, and occasionally ate some of the "Death Camas" by mistake (the flowers, white on the safe plants and purple on the deadly ones, aren't visible in winter when the roots are dug for food). The difference? The purple ones are colored by selenium they've concentrated from the soil where it's available...
    Go to the toxicity link provided above, ^0 micrograms for women and 70 for men MINIMUM amount per day. Max if you read further is 400 Micrograms.


    also Ken I understand the difference between the powdered and the pressed pill. I also knw he washed it up thus any that had dried, was again rewet. Any amounts that would remain after he washed up the mess, would be so infintesimal as to not be a bother. Especially if he used a good soap to help wash it with. We all need to take precautions, but I see too many who worry about minimal risks as if they were about to destroy the person and the planet. Caution yes, paranoia no.
    Non Digital Diva

  8. #38
    DKT
    DKT is offline

    Join Date
    Sep 2002
    Posts
    504
    something similar happened at work a month or two ago--had an old kodak one gallon glass jug of brown toner, crack open unexpectedly--very neat too, a tiny little chunk popped out like a piece of a puzzle-- that oozed out onto the floor and then under the tiles, smelling pretty much like a backed up sewer. took us almost all day to clean up and we had to rip up the floor tiles as well, and hose the area down. used up a gazzillion towels, had to throw away the mops, and all sorts of other stuff that was on the floor that the toner had screwed up. had to take a shelving unit outside and hose it down. real mess--had to wear smocks, gloves, goggles...one of the guys had to pretty much trash his shoes. it took about a day or two to get the lingering odor gone.

    I'm not trying to say don't worry about it, but.....well, accidents happen. In retrospect, it would be better to try to absorb the chemistry with kitty litter or a pig-a-log or something than to wet mop it up. But, now that it's dry, I would just mop the hell out of the area and then throw out the mop head and all the cleaning stuff that was in contact with it.


    oh well, good luck detoxifying the site....

  9. #39
    KenM's Avatar
    Join Date
    Apr 2003
    Location
    Calgary, Alberta
    Shooter
    4x5 Format
    Posts
    800
    Quote Originally Posted by Aggie
    also Ken I understand the difference between the powdered and the pressed pill. I also knw he washed it up thus any that had dried, was again rewet. Any amounts that would remain after he washed up the mess, would be so infintesimal as to not be a bother. Especially if he used a good soap to help wash it with. We all need to take precautions, but I see too many who worry about minimal risks as if they were about to destroy the person and the planet. Caution yes, paranoia no.
    Paranoia? I was advocating care when cleaning it up. The facts are that selenium is toxic, especially in powder form - I just wanted Sean to be aware that the dust can be dangerous.

    But, this thread is starting to degrade - we've all made our points, and I'm sure Sean has already cleaned up his darkroom, and is sitting there watching this with a rather bemused look on his face. There's pretty much no sense taking this one any further.

    Fini.
    Cheers!

    -klm.

Page 4 of 4 FirstFirst 1234


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin