Getting back to the darkroom

[tom_mccabe]

Good afternoon. After about 10 years I'm getting back into my darkroom for a special project. I have a half full bottle of Selenium toner that's been sitting there all this time and I'm wondering if what's left in there might still be good. Any thoughts?

 

All the rest of the chemicals that were in there are waiting to go to the disposal site; I'm sure they're no longer good.

 

My darkroom is in my garage and is subject to pretty wide temperature swings over the course of the past years. If it's probably no longer good, I have a local place to dispose of it. I'd appreciate any thoughts. Thanks!

[Alan Marcus]

First -- No need to make a special trip to a disposal site! If you are not on sceptic tank (rural area), then OK to feed them to the sewer system. The main thing a sewer system wants to avoid is silver in your effluent. While spent photo waste does contain some silver, unused photo chemical are void of silver. Some forms of silver are toxic. Photolabile waste does contain but photo waste quickly combines with sulfur from the fixer and this renders the silver inert. The real concern is BOD and COD. Biological and Chemical Oxygen Demand. In other words, photo effluent takes on oxygen as it travels down the sewer to the waste treatment plant. Your tiny oxygen demand will be just a thimble worth. Don't worry its OK to dump, Big photo labs must pre-treat to knock down the oxygen demand. As to the Selenium, test on a small quantity of photo paper. It will work or not. If not, then replace. Ran 7 giant photolabs each 20,000 rolls a day. Was well schooled on photo waste handling. Also, if you feel better about it, take your photo chemical to a disposal site.

[tom_mccabe]

Thank you, Alan. I appreciate the input. Some of the chemistry I have is some unmixed D-76 powder. I don't know if it's still good or not. It's quite old.

[glen_h]

First -- No need to make a special trip to a disposal site! If you are not on sceptic tank (rural area), then OK to feed them to the sewer system. The main thing a sewer system wants to avoid is silver in your effluent.

(snip)

 

As well as I understand the rules around here, you are supposed to mix developer and fixer before going down the drain.

 

That partly cancels out some of the effects.

 

As you note, silver is one that they don't like, but that is mostly silver in solution.

Metallic silver will just fall to the bottom and not do much.

 

Our local household hazardous waste site will take photo chemistry.

I gave them a bottle of used blix once, though I do remember when I was

in college (many years ago), just putting it down the drain. It would make the

the drain shiny when it went into the sink. It might eventually make holes in

the drain pipes.

[Alan Marcus]

As well as I understand the rules around here, you are supposed to mix developer and fixer before going down the drain.

 

That partly cancels out some of the effects.

 

As you note, silver is one that they don't like, but that is mostly silver in solution.

Metallic silver will just fall to the bottom and not do much.

 

Our local household hazardous waste site will take photo chemistry.

I gave them a bottle of used blix once, though I do remember when I was

in college (many years ago), just putting it down the drain. It would make the

the drain shiny when it went into the sink. It might eventually make holes in

the drain pipes.

The silver in solution combines with the sulfur in the fix to form inert silver sulfide.

[Alan Marcus]

Thank you, Alan. I appreciate the input. Some of the chemistry I have is some unmixed D-76 powder. I don't know if it's still good or not. It's quite old.

The powder should be OK if it is not black. Mix some up and test in the light by swishing a short piece (tongue) in the fluid. Film should change from milk to black quire fast. If it does this then its OK. A home photo lab can't dump much toxic stuff -- Siver is considered by the municipality to be the bad boy, actually its oxygen demand.. Fixer causes chlorine to effervesce out of solution. This is the same stuff used by tropical fish hobbies to rid their aquariums of chlorine. Fixer, in quantities will cause the chlorine to go out of solution at the local treatment plant. Ups their cost of operation but a home photo lab dumps too little fixer to make a difference.

[glen_h]

The powder should be OK if it is not black. Mix some up and test in the light by swishing a short piece (tongue) in the fluid.

(snip)

 

I did one time have a sealed, but somewhat old, Kodak developer bag, I think Dektol.

 

The powder was a little brown, and the solution dark brown. Darker than I have

ever seen developer. Almost coffee color. That went down the drain.

 

Not all developers are the same, but for most that is about right.

 

Mixed should be clear, or just the tiniest bit brown. Though they actually

work darker than we might think.

[rodeo_joe1]

I did one time have a sealed, but somewhat old, Kodak developer bag, I think Dektol.

 

The powder was a little brown, and the solution dark brown. Darker than I have

ever seen developer. Almost coffee color. That went down the drain.

 

Not all developers are the same, but for most that is about right.

 

Mixed should be clear, or just the tiniest bit brown. Though they actually

work darker than we might think.

Agreed. If the smaller packet of D-76 has dark brown flecks in it, then it most likely won't give the proper development times when made up.

 

However, the large amount of de-oxidising sulphite in D-76 can regenerate some slight oxidation of the Metol developing agent. So if the solution is water-clear when made up, then most likely the developer will be OK. A yellow or brown tinted liquid won't be good, since even when fully spent a solution of D-76 remains quite clear.

 

Easily checked by dipping an offcut of film in an egg cupful of developer in room lighting for the recommended time/temperature. If the film turns fully black, then the developer's OK.