Shelf life of sodium sulfite?

Anyone know how long this stuff lasts? I was given a mostly full plastic bottle of it - probably from late 80s to early 90s. It is in a fine powder and looks nice and white.

It's 2 pounds (almost all there) from Edwal. Listed as photograde.

Thanks!

I cannot tell you how long it will, or did, last; that will depend on its storage and whether or not it had been opened. Sodium Sulfite will be subject to oxidation to the more stable Sodium Sulfate and may lose or gain waters of hydration, depending on the storage and if it is prone to that. If you have opened it, I would fill the bottle with an intert gas, but not Carbon Dioxide, and recap it and see what happens.

Wikipedia usually has good entries and they may even have a good physical description of what it should look like. Different forms are usually not the same, as far as looks go

Depends on the type of plastic used for the bottle. I personally buy sodium sulfite in relatively large amounts and transfer it to several glass canning jars (Mason jars). You can always use it to make HCA it won't matter if some of it has gone to sulfate.

I would use it to make "non-critical" solutions, such as HCA. If you use the wrong amount of it there, due to it taking on water from the air over the years, it won't matter as much as if you do it with a developer.

It will most likely last nearly forever, if kept dry.

I have some from the 60s and it's fine.

Still useful after all these years

Kirk Keyes said:

I have some from the 60s and it's fine.

Click to expand...

Must be some groovy sodium sulfite. I have a few pounds left that I bought to clear Polaroid type 55 negs. I sure miss that film

Like Kirk says it shouldn't go off well stored.poorly store it'll go hard & solidify anyway.

Ian

This isn't solidified at all, and shows no signs of taking on moisture. Looks like it's safe to use.

Thanks all.