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How long do chemicals last

L Gebhardt

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Joined
Jun 27, 2003
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2,364
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NH
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How long do different bulk chemicals last? I am mixing up some Ansco 130 for the first time in a few years. I know Glycin goes bad, and mine is now dark brown. How can I tell if Metol or Hydroquinone have gone bad? Do sodium sulfite, sodium carbonate, potassium bromide go bad?
 
If they are in the original sealed bottle and it has not been opened to let air get in they will last for years.
 
HQ can go bad. When it does, it turns green and takes on a very strong odor. Metol blackens and takes on an odd odor, but it is rare for either to go bad. Usually, left on their own, they just keep chugging along. They should be fluffy powder or needle like. Sulfite turns into Sulfate slowly and loses strength. Carbonate and Bromide mainly cake and turn into hard lumps.

PE
 
Thanks. Looks like my HQ and Metol are still fine. Can you tell if Sulfite has turned into Sulfate? Does cake Carbonate and Bromide still behave the same way as fresh (is it the same chemical)?
 
Caked chemicals are most always the same but harder to handle. Sometimes they absorb water and you need more of them for the same effect.

There is no simple test for the Sulfite, sorry. It should not affect a paper developer except for tray life.

PE
 
L Gebhardt said:
Sulfite has turned into Sulfate?
Click to expand...

For a crude test, put some in water - if it doesn't feel soapy then it's shot. Put some fresh sulfite in water so you get an idea of what it feels like.

S. Carbonate washing soda will increase in size and split its cardboard box after a few years on the laundry room shelf so something changes if it is exposed to moist air for long enough.
 
I keep my dry glycin in a sealed glass bottle, in the freezer. It stays whitsh to tan quite a while longer that way - like a few years.
 
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