You're 35mm Films and Slides are Dying Pt.IV

Mold growth on slides and negs is a huge problem, as the fungi actually eats into the emulsion layer. Trying to remove the growth with liquid cleaners most of the time results in more damage than good. Also a dry mold can spread spores very easily to other slides. Needless to say damp conditions promote this damage. Once this damage starts it’s hard to stop and precious negs and slides can not be saved.


The bottom line is that slides and negs under normal storage conditions begin to degrade after about 20 years. Some will degrade earlier and some later, based on other factors.