Nitrate

The following is from the "Collection, Use and Care of Historical
Photographs" by Weinstein & Booth:

"We believe that all usable nitrate-base film should be duplicated as
soon as possible and the film disposed o immediately.  To extend the
life of nitrate-base film, it most be isolated and stored in specially
ventilated files. It will have to be stored in a fire-proof structure at
lower temperatures and humidity levels than are necessary for other
photographs.  Unless your institution has ample funds for safely storing
these unfortunate photographs, we feel that caring for them while they
continue to deteriorate and endanger other photographs is not wise"

Re:>Nitrate Film - effect on rest of collection:

"Cellulose nitrate, from which nitrate-base film was made, is relatively
 unstable chemically. Even under normal storage conditions, the material
 will slowly decompose, giving off powerful gases, nitrogen dioxide and
 others. As these gases form, they will react with the base of the film
 and the emulsion, accelerating further chemical disintegration in a
 continually intensifying cycle of destruction.  Not only do these gases
 react chemically with the film base from which they are produced, but
 they also destroy negative envelopes. These gases will create the same
 chain-like reaction with other nitrate-base film nearby, ruining images
 of ANY OTHER KINDS of photographs in the storage area."

There is also a publication called " Hazard Handling & Storage of
Nitrate " from Eastman Kodak in Rochester you may wish to check out.

As far as I can see your HVAC system which "recirculates air with
limited fresh air intake" is not the proper approach. Good ventilation
during storage, which allows the escape of the nitrogen dioxide fumes is
imperative for safety and in prolonging the film's life.

If you are interested in talking to a curator specializing in nitrate
films you may wish to speak to one of the film libraries out here in
L.A.  It's a major problem here.

Ralph Roessler\Paper Technologies, Inc.

                                  ***
                   Conservation DistList Instance 4:9
                  Distributed: Tuesday, August 7, 1990
                        Message Id: cdl-4-9-001
                                  ***