Shelf life of chemicals

[Dietrich Floeter]

I have on my shelf a tub of Hydroquinone and one of Elon from Kodak and another tub of Elon from another mfg. Does anyone have a feel for the shelf life of these chemicals? I recently made D-23 from this group with good results but am curious what someone else's experience has been.

[Ken Lee]

With Elon (also known as Metol) look for discoloration: if it is dark-colored, it has probably oxidized and has lost its strength.

Ultimately, if the results are good, the results are... good

[Dietrich Floeter]

Thanks Ken. A bit more testing is in store and then soup on.

[blueribbontea]

I use a Kodak bottle of Elon from the 60's and even though it is a bit brown it makes fine D-23. I have a cardboard can of hydroquinone that is probably at the latest from the 1930's. The crystals are nice and white and I use it regularly to make print developers. I have found with it though that it does better if I double the quantity.

[dsphotog]

My Elon is in a Kodak brown glass jar, it has a Camera Center price sticker with a 2 letter & 5 digit phone number LA 4-7361.
I just mixed some PMK developer, I just used up the last batch of concentrate, mixed a year ago.

[Dietrich Floeter]

Antique chemicals abound! My containers are plastic and the crystals are whit-ish also. Up on the shelf I also have a few collected cans of developer that I have presumed were shot but maybe not. Thanks for the input.