Re: Dreaded fungus

From: jfulton <jefulton1@comcast.net>
Subject: Re: Dreaded fungus
Date: Wed, 17 Dec 2003 22:07:17 -0800

> One of the best ways to inhibit it originally is to use a hardener in your
> fix. Generally with color, particularly E6 there is formalin (37%
> formaldehyde) of a small proportion in the pre-bleach or conditioner step.
> What this does is to make the emulsion more compacted, or hard,
> therefore inhibiting moisture.

Formaldehyde does a couple of effects in color processing, such as
stabilizing dye. But limiting to this specific issue, I am not sure
about your explanation of inhibiting moisture. If formaldehyde is
indeed found effective against fungal growth, it is more likely
through making gelain less bioavailable. Hardening increases cross
linking of gelatin matrix, and therefore it is likely less readily
available to microorganisms. However, hardened emulsions still get
rotten without bactericide agents. Commercial films and papers contain
a blend of a few bactericides, but I think most (if not all) of them
dissolve away during processing. I think it's quite practical to add
bactericides to wetting agent to be used as the last step of
processing, though it is by no means a substitute for proper storage.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)