Life span of Selenium Toner working solution

[brian steinberger]

I have diluted a gallon of selenium toner 1+19 with hypo clear. I keep this gallon and use it over and over during printing sessions. Does anyone have a suggetion as to how long this gallon will last and offer adequate toning?

[Andre Noble]

Rough guess: 25 to 50 8x10's. PS: never understood people using Hypo and Toner together. Perhaps it's me missing out. i forget the exact reason,but i don't use hypo clear /permawash anymore.

[Louie Powell]

Brian -

Selenium toner mixed 1+19 in water should process 25-50 8x10's or equivalent, as Andre says. And it doesn't matter whether those prints are done at one time or over a year - the toner just keeps working until the selenium content is depleted.

But mixing with hypoclear introduces an additional factor. Hypoclear does not have a long shelf life when mixed to working strength. Everything I have seen or read advises using working strength hypoclear as a one-shot solution.

I do not mix toner with hypoclear - I put prints through a hypoclear bath before toning, and again after toning (toner contains ammonium thiosulfate). But like good scotch, selenium toner should be mixed only with water.

[paulr]

"Everything I have seen or read advises using working strength hypoclear as a one-shot solution."

really? i always kept it around for months without problems. if it went too many months, it would grow mold, but within reason, it always help up a while, and did a fine job with both prints and film.

i agree that it has nowhere near the longevity of selenium.

[Doremus Scudder]

Stepping up on the soapbox again...

Brian,

Your selenium toner will last indefinitely. Mixing it with Hypo-clear will not hurt the longevity of the toning solution, but the hypo-clearing function will be exhausted well before the toner is. Also, toner can be replenished and used practically forever.

Additionally, dumping selenium, even small amounts, into the sewer system or the environment is unnecessary and environmentally unsound.

Therefore:

Mix your toner without hypo-clearing agent. Use a separate hypo-clearing bath one-shot immediately after the toner. Keep track of its capacity and toss it when it is exhausted.

When your toning times become too long, add a bit of the toner stock solution to your exhausted toner working solution. This will replenish it. The amount is not critical, since you can vary the time, but start by adding small amounts (you can always add more if the time is still too long, but you would have to dilute further if the times are too short).

Filter your toning solution through coffee filters before and after each toning session. This will remove the black precipitate that forms (which, however is not damaging to prints, just ugly).

Use your toner like this, replenishing and topping up the solution for years. There is never any need to toss it. I have a couple of gallons at different dilutions that have are going on four years now, no ill effects, and the prints pass all the residual hypo and silver tests with flying colors.

If, however, you really MUST discard toning solution, use it until the times become very long. Then, toss a couple of discard prints into the solution overnight. This will capture the largest part of the selenium left and the remaining solution will have very little selenium in it. This solution can be safely discarded. (Some on the forum use it to water their house plants with, claiming a fertilizing effect. I would not recommend it personally though...). Dumping into the city sewage system should be alright at this point.

Do not use arbitrary capacities (e.g. 50 8x10/gal, etc.) for selenium toners. The type of paper, the amount of toning you wish and the amount of light versus dark areas in your prints will all effect the lifespan of the toner. The more toner is bound by the silver in a print (and the residual silver carried over into the solution from fixer) determines the life of the toner, and it is hard to calculate. Better is a simple visual test: How long does it take for the print to achieve the degree of toning that you wish? If the time is too long, add some stock solution to the toning bath. If too short, dilute. That is all there is to it.

If you wish no tone change, but are toning for "archival permanence," forget it. Prints that have no visual change in tone or noticeable change in D-max derive little benefit as far as permanence goes. Fully toned prints are the best protected, prints with little or no tone change are not protected much at all.

Best,

[Richard Schlesinger]

This is all extremely useful. Two further questions, however; I have never run across any of this information in any of the many books I have read on photographic printing etc. I don't believe the standard and always reliable Ansel says anything regarding the life of selenium toner. Where can I read some of this stuff? The other probably has already been answered, i.e. does the type of container for storage of diluted selenium toner make ny difference? One would assume not, but . . .

Many thanks to Doremus Scudder, whoever and wherever you are!

[paulr]

"(Some on the forum use it to water their house plants with, claiming a fertilizing effect. I would not recommend it personally though...). Dumping into the city sewage system should be alright at this point."

ha, yeah i also recommend against watering the plants with it, making your coffee with it, etc..

i don't think it's such a bad thing for the sewer system, though, if you dilute it enough. we work with much worse things for the environment than selenium. exhausted fix is much worse to dump; so is anything containing silver nitrate or chromium.

but selenium, despite its reputation as a heavy metal, is a close relative of sulfur and is relatively harmless in small quantities. by small quantities, i mean what you'd get by diluting your waste in several gallons of water, and then adding it to the several kajillion gallons of the municipal waste water. at this point its dilution will probably be similar to what occurs in nature in some places, and should harm neither the sewage treatment plant nor the fishes.

the real metal ion wastes ... silver, chromium, etc. ... are a different story. please don't dump these.

[Jim Ewins]

Our bodies need certain trace elements, selenium is one. Soils can be depleted of these trace elements and need replenishing. The extent of dilution and form of the element is the question. I'd not use it on my vegi garden but will consider some experiments in the ornamental garden.

[neil poulsen]

"i don't think it's such a bad thing for the sewer system, though, if you dilute it enough."

I've gotta respectfully disagree. :-)

I've been studying this recently, and selenium is on the hazardous chemicals list. Every source I've seen (e.g. Kodak) recommends proper disposal, which doesn't include sending it down the drain. (Whether or not it's diluted.) As the saying goes, dilution is not a solution.

I don't know what other states have, but Oregon has a county affiliated agency that will accept small quantities of chemical waste for a nominal fee from very small users like photographers. (No more than 220 pounds, about 25 gallons, of liquid per month.) And anyway, Doremus suggests an option for avoiding diposal altogether.

There's too many pressures on the environment as it is.