D-76 stock solution storage life

[GRHazelton]

I have just inadvertently tested the storage life of D-76 stock solution. I normally make up 1 gallon of undiluted solution using distilled water, put it up in 1 liter heavy plastic bottles with as much air as possible squeezed off. These I then dilute 1 to 1 as needed.

Yesterday it seemed time to mix up a fresh gallon. Searching around in my storage cupboard I found to my chagrin a liter bottle, unused, labelled 3/24/2010. It had been kept a room temperature, and in the dark.

Since I had a cassette of film used just for fooling around I processed it, the results look good. Kodak, with commendable caution, cites a 6 month storage life. While I can't recommend over two years, at least it does seem to work properly.

 

[cliveh]

I quite often use D76 which is over a year old and kept on a window ledge. As long as you don't let it oxidise it will probably keep for 2 years or more.

 

[pstake]

Good to know!

 

[Rich Ullsmith]

Two years easy, as long as you don't mix the powder and water in a blender.

 

[brian steinberger]

...however it is well known the pH of D76 rises over time with storage, making it more active. This would tend to raise contrast.

I was always curious, over how much time are we talking? I mix up 5L of ID-11 and use it all within 3 months.