Smithsonian press release

I am reluctant to make public comments without having seen the research
Jim Druzik refers to, but the more I think about it, the more important
it seems to say something about this press release. There are many
issues which need talking about; I just want to mention those that are
most immediately important to me.

The article seems to suggest that there is an "on-off" switch for
deterioration, and that the CAL researchers have discovered that it is a
much wider switch than previously believed. It still sounds like it is
an "either-or" situation - either you are inside the range and
everything is okay, or you are outside it and everything is
catastrophic. Some of us have fought for a long time for an
understanding that it just doesn't work that way; that, in fact, we work
with a sliding scale. Collections stored in higher temperature and/or RH
will survive in a useable state for a certain period of time, and those
stored in lower temps and/or RH will survive for longer periods. The
crucial question to ask is: "how long do we want/need this to survive?"
If the answer is: "as long as we can", then we aim for the coolest,
driest, most stable conditions we can afford. (I am over-simplifying, of
course, and thinking mainly about paper and photographs.)

This approach is based on the fundamental understanding that chemical
reactions tend to go quicker the more energy and moisture that is
available. Still assuming that principle to be true, I just don't see
how they can suggest that there is no significant difference in the rate
of deterioration between 31 degrees and 11 degrees C, and between 65%
and 35% RH??!

I can only assume that the researchers were really saying that you don't
necessarily get sudden catastrophic loss when you move away from 21
degrees and 50%. That makes sense to me. But to say that "there can be
as much as 15% fluctuation in relative humidity and as much as 10
degrees Celsius difference in temperature" when talking about "ideal"
conditions just seems a nonsense, and a dangerous one.

It is true that many high quality papers will remain reasonably flexible
for even hundreds of years at elevated temps or RH. But this ignores the
vast bulk of poorer quality papers containing materials that are just
waiting for a bit of energy and moisture to get their deterioration
rates up. Same goes for photos.

It is also true that most library and archive collections can cope with
a fair amount of seasonal drift in conditions, because of the inertia of
large masses of paper and the buffering effect of packaging. On the
other hand, this is crazy for materials like film and tape collections
where changes in conditions can have a dramatic effect on physical
dimensions.

On the question of saving energy, we believe that we can save very
significant amounts by installing more precise building management
control systems, rather than taking the grocery store approach.

I find it hard to make sense out of the second last paragraph. "At
higher values of temperature and relative humidity, they say, physical
damage is minimised" is either wrong, or just too subtle for me.

And I'm not sure how I would characterise statements like "As
scientists, we don't work from the idea that each object in a museum is
unique. ... Rather we start by looking at the whole picture ...", when
it seems that their approach has ignored the diversity of collection
objects and the realities of collection preservation.

I believe that the true situation with environmental control is fairly
subtle: as conservators we probably have been panic merchants and given
people the idea that there are "ideal" conditions which must be achieved
at any cost, whereas we should have been encouraging decisions about
what was ideal or acceptable based on decisions about what outcomes are
needed for the collections in our care. I can see a faint possibility
that the CAL research might support such an approach, but if it does, it
has been hopelessly lost on the way out.

So, taken at face value, a lot of the statements attributed to the
researchers seem questionable. The way they are reported is certain to
encourage the view that institutions can forget about environmental
conditions as a factor. I'm not sure what politicians in USA will make
of that, but I have a fair idea how our local breed would use it next
time anyone asks for funding for a purpose built building!

Colin Webb
Manager, Technical Preservation
National Library of Australia

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                  Conservation DistList Instance 8:23
                Distributed: Friday, September 30, 1994
                        Message Id: cdl-8-23-001
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