Vinegar syndrome

Deborah Sutherland <d.sutherland<-a t->vam< . >ac< . >uk> writes

>The National Art Library at the Victoria and Albert Museum, London,
>recently opened a Chubb fire safe that had been inaccessible for two
>decades.  The contents had vinegar syndrome and have been disposed
>of appropriately, but we would like to re-use the safe to store
>nineteenth century manuscripts.  However, even after some weeks of
>"airing" it continues to have a vinegar odour. ...

Many of the recently suggested postings for the problematic safe
involve the use of a "sink", such as zeolites or mat board, to
absorb the odour.  I agree that this may be effective if the source
of the odour is limited, but this is not known.  If
flushing/cleaning/replacing the surfaces (including just leaving the
door open and directing a flow of air into the safe) is not
effective, you must consider other possible sources for the odour.
It could be entering from holes, cracks or seams leading to the
exterior of the document chamber.

"Fireproof" safes usually consist of an inner document chamber,
surrounded by a fire-resistant material (usually plaster), with an
exterior protective sheath and locking door.  While it may be
obvious that such a device should completely isolate the contents of
the document chamber from the protective surrounding material, this
is more easily stipulated than accomplished.  Deborah Wahl's
comments regarding the safe's interior as a microclimate are
excellent.  I suspect though, that there is still moderate air
exchange with the exterior environment and the plaster protective
layer.

I suspect that there is a substantial reservoir of odour in the
plaster, and it will continue to leak into the document chamber.
However you need not discard the safe!  You could encapsulate your
manuscripts in a barrier film envelope such as Escal, which would
effectively prevent the ingress of air-borne pollutants.  Further,
you could include an oxygen/pollutant scavenger, such as RP type,
with the documents in the package which would protect your documents
from oxidation.

Note that when a fireproof safe is heated, the plaster filling will
release moisture (and more).  The release of this moisture will
prevent combustion of the contents for some time, but some (or a
lot) of the moisture might be forced into the inner chamber.  For
this reason alone, I would consider anoxic packaging useful for
important documents kept in any fireproof safe.

A little more on this topic can be found on CoOL by searching
"Storing library materials in safes"

Jerry Shiner
Keepsafe Microclimate Systems
+1 416-703-4696


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                  Conservation DistList Instance 27:37
                  Distributed: Sunday, March 30, 2014
                       Message Id: cdl-27-37-001
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