Chemical (fumes) that fog paper?

[polyglot]

I've heard that some chemicals (toner?) will fog paper that is stored in close proximity. Does anyone have a definitive list of the problematic ones? I need to do some cupboard-consolidation and it'd be nice if I could store paper in a darkroom cupboard.

I have B&W and RA4 paper, plus:
- rapid fixer in working and concentrate form
- glacial acetic (messy bottle)
- concentrated multigrade (messy bottle)
- sealed dry stuff (xtol, d76, etc)
- sealed conc devs (rodinal, HC110)
- Xtol in a Mylar bag/box, D76 in PET
- C41, RA4 and E6 kits as working solution (PET bottles) & concentrates (little glass bottles)

I am pondering getting Selenium and Sepia toners maybe next year, presumably that means I'll have some more bleaches too.

[RalphLambrecht]

i'll add to the list with sulphide toners

[Gerald C Koch]

Also add anything such as selenium toner that releases ammonia gas. It's best not to store film and paper in the darkroom.

[polyglot]

So it's just toners that are a problem? Fixers and developers cause no fogging issues?

I could store my toner (if/when I get some) in the shed.

[Photo Engineer]

Sodium Sulfide, Ammonia fumes, any fixer dust, all of these can fog film or paper. Acetic Acid fumes or drops can leave white spots on film or paper. Sodium Chloride, Iodide or Bromide crystals or stock solution can leave white dots on film or paper.. Alkali, such as NaOH, KOH, K2CO3 or Na2CO3 can cause dark spots on film or paper as can Phosphates.

PE

[RalphLambrecht]

as gerald said.just keep film and paper outside the darkroom. i store them in a fridge, not freezer ,in the mattingand framing room/studio.

[polyglot]

OK, not-the-darkroom it is then. I don't get to have multiple dedicated studios or anything (my darkroom is a 2.5x1.5m laundry with a 600mm bench down one side and a little sink in the end). I do have another man-cave, it just doesn't have the nice big 600x600mm cupboards that would hold 16x20 paper quite nicely. Bottom of the 19" rack, maybe.

The film stash gets me in enough trouble with the fridge+freezer as it is. Paper would be asking to sleep on the couch.

[MattKing]

The film stash gets me in enough trouble with the fridge+freezer as it is. Paper would be asking to sleep on the couch.

If you are storing at room temperature, under the couch is a great place to keep your 16x20 paper - but under the bed is even better

[nworth]

Sodium Sulfide, Ammonia fumes, any fixer dust, all of these can fog film or paper. Acetic Acid fumes or drops can leave white spots on film or paper. Sodium Chloride, Iodide or Bromide crystals or stock solution can leave white dots on film or paper.. Alkali, such as NaOH, KOH, K2CO3 or Na2CO3 can cause dark spots on film or paper as can Phosphates.

PE

You mention sodium sulfide, but hygrogen sulfide gas, which can be produced by a lot of things like even very weak acid on residual sulfides, is also an obvious candidate. So is hydogen selenide, which sometimes escapes from selenium toner or acid treatment of something containing selenides (like toned prints). I don't know what effects, if any, sulfur dioxide and selenium dioxide might have. Sulfur dioxide is pretty common in the darkroom. Many amines, as well as ammonia can cause fog. Of course, the rate and intensity of the problem will depend on the concentration of the chemical and the length of exposure as well as what it is. For you as well as your photographic materials, the darkroom should be decently ventilated. That will go a long way toward solving the problem. Sensitive materials should normally be stored away from darkroom chemicals and away from the sink. Paper should be kept in the plastic bag it came in, and film in its sealed containers (or in a sealed plastic bag, if necessary). That way, fumes have less chance of getting to the materials. Since the fumes generally drift upwards with the air currents, keep the paper and film lower than the chemicals and out of their ventilation path.

[Photo Engineer]

Sodium Sulfide emits Hydrogen sulfide. That would be the primary source in a DR. Bad fix is the second source.

My darkroom is virtually unventilated but I have had no instances of fog from any of the unusual chemicals that I store there including Trimethyl Amine and some other oddities including solid Sodium Sulfide.

So, even though this "can" happen, I have never ever seen it happen except to the odd occasional sheet of film or paper left out in the DR for a prolonged period of time when one of these harmful items was present. So an example would be a sheet of paper left out overnight in the dark and a tray of Sodium Sulfide toner. That is how extreme the conditions would have to be to cause a problem.

PE