From: Jack Fulton (jefulton1@home.com)
Date: 03/07/01-08:50:25 AM Z
> Does anyone have any information of the shelf life of packaged
> darkroom chemistry? Particularly, D-76, Dektol, HC-110, Fixer, etc, etc.?
A good question Bob . . Fixer will last indefinitely. The formula is very
simple for a packaged fix. If it is the liquid (ammonium thiosulfate) it may
well 'settle' out and when that milky yellow precipitate or crust form, it
is not as useable.
I have HC110 on my shelf. Been there for years. It turns a bit dark and if
any other developers turns a rather dark drown, it should not be use. Hence,
shelf life is not a time based but more a visual based phenomenon. The
primary components of packaged developers are most often of the MQ (metol
and hydroquinone are the developing agents) variety. The other chemicals are
sod. sulfite which is a preservative and lasts, well, a long time; sodium
carbonate which is basically potash and used in swimming pools to balance
pH; and potassium bromide that lasts and lasts. So, simply, you are safe
even if the dry chemicals have turned a slight brown in color.
Jack Fulton
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