Microfilm is the only media with a 500+ year rating.
The only way to take advantage of it's ability to last that long is to
handle and store it properly.
There are Industry Standards for the procedures to be followed for the
handling and storage.
Acetate films can meet ANSI and ISO standards for permanent storage "but"
they are much more susceptible to temperature and humidity than polyester
films. Since the tolerance levels for acetate films are much tighter than
polyester the cost to store is higher. Therefore the acetate films are
often duplicated onto polyester films to insure a long life.
If acetate films are not stored properly the natural deterioration
(breakdown of the acetate support) will accelerate. The process of this
breakdown is called vinegar syndrome and once it starts it can not be
stopped. Also the films that are deteriorating will cause the acetate films
around them to begin to deteriorate as well.
Polyester films were introduced in the mid 1950s. All three microfilm
manufacturers were producing and distributing their camera films on
polyester by 1980 and most service bureaus were using polyester based films
by the mid 1980s.
If you have vital records on acetate film, you need to convert them to
polyester or follow the standard recommended guidelines for their
--- John Glover
--- 800-969-2556, ext. 367
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