U of S | Mailing List Archive | alt-photo-process-l | low humidity is the key to prevent mold on film

low humidity is the key to prevent mold on film

Sorry I've been super busy and been looking at subject line
alone so didn't detect this topic until the subject changed.

There is no need to go that far. Separating molded slides is a
good idea, but keep the RH as low as possible, below 30%, in
both batches. Also, keep the temp low. Growth of mold/fungus
is significantly inhibited by lower humidity. Low humidity
generally helps longer life of silver and dye images as well.

Some dyes require presence of air, and others don't need air,
for good keeping property. Check what kind of coupler
technology was used before using vacuum containers for

Formaldehyde in the final rinse was to inactivate unused
couplers to prevent discoloration. It does not stay there to
prevent fungal growth. Either way, formaldehyde was commonly
used in the final rinse in color processing until Konica came
up with new technology in 1990s, which was adapted by Fuji and
then Kodak.

There are some effective fungicide that may be incorporated to
the final rinse solution. However, the actual final rinse
solution incorporates agents that are more effective against
bacteria rather than fungus, because the solution can be
rotten while they are in the tank. We noted Tetenal made
Mirasol 2000, a final rinse solution that contains a
isothiazolinone bactericide, but that agent is also not
particularly effective to fungus. I am yet to see final
solution that is safe to silver image and gelatin, and then
also effective to prevent fungal growth in commercial products.

Ryuji Suzuki
"Strange how people who suffer together have stronger connections
than people who are most content." (Bob Dylan, Brownsville Girl, 1986)

From: "Christina Z. Anderson" <zphoto@montana.net>
Subject: Re: Do dichromates change with age?
Date: Mon, 14 Jul 2008 09:53:07 -0500

> You know what is interesting?  The mold is not on the ones from the early 60's but the ones from late 70's, so I wonder if Kodak quit putting formalin or something in their Kodachromes.  All were stored in the same place. Or maybe the storage boxes changed...who knows, but the molded ones would require so much digital touchup it is not worth it.  BUT they're great "alt" shots, heheheheheh.
> Chris
> Chris,
> Keep the moldy slides away from the rest of your stuff! In a different
> building if possible! With that many slides and negatives you'll
> definitely need to sept up something faster than a scanner. I would
> rig up a dslr copy devise, like a good macro lens or an enlarging lens
> on bellows, and zip through them quickly.
> I've found some of my old negatives silvering out. Not fun trying to
> rescue them either.
> Sam