[Nhcoll-l] Animal bone collection and temperatures

[John E Simmons]

Nadja,
There is a very good, brief section on the preservation of "Bone, Antler,
Ivory and Teeth" by Christopher Norris and Robert Waller on pages 852-852
of *Preventive Conservation: Collection Storage*, edited by Lisa Elkin and
Christopher Norris. To summarize what they say, you are correct to be
concerned with freezing temperatures and relative humidity due to problems
with fracturing, mold growth, chemical aging rates, and migration of oils.
Brief excursions of temperature to near freezing are not too harmful except
as temperature affects relative humidity. Low relative humidity will cause
fracturing of teeth and long bones, and frequent variations in relative
humidity may do the same. The recommendations Valerie provided are good.
Keep in mind that teeth are far more susceptible to damage from fluctuating
relative humidity and low relative humidity than bone.

In addition, what I suggest is talking to the building engineers or
administrators or whoever controls the thermostats and heating equipment
about how to go about the energy saving measures and try to convince them
that rather than simply prevent the temperature from going below freezing,
they need to investigate ways to conserve energy while still maintaining a
relatively stable storage environment to minimize humidity excursions.
There has been some work on this in various museums in different climates,
ranging from simply turning off heat or cooling over the weekend when the
collection storage areas are closed (which, in an adequately insulated
building, usually keeps the temperature and humidity within a desired
range) to establishing a lower temperature (hence less energy use) that
still keeps relative humidity within an acceptable range. This latter
method is often more energy efficient, depending on the building design and
materials, as it is usually more efficient to use a steady temperature of,
say, 10 or 12 degrees, than to allow a large space to cool down and then
heat it back up (which causes serious changes in relative humidity).
Another solution is to use microclimates for very susceptible materials
(such as teeth) by placing them in polyethylene boxes with treated silica
gel, but that may be prohibitive for a large collection such as yours.

There are a number of publications available that address these issues.
Three that are available for free download include:

Padfield et al. 2013, Low energy museum storage

https://www.conservationphysics.org/storage/low-energy-museum-storage.html



Maekawa and Garcia Morales 2006-Los-cost climate control system for museum
storage facility

https://www.getty.edu/conservation/our_projects/science/climate/valle_de_guerra_PLEA_2006.pdf



Kerschner 2008-Providing safe and practical environments for cultural
property in historic buildings

https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.568.1438&rep=rep1&type=pdf


No doubt other people on this list have either had experience with these
sorts of strategies or perhaps can recommend other useful publications to
address this issue.

Glad to see you posting to nhcoll!!

--John

John E. Simmons
Writer and Museum Consultant
Museologica
*and*
Associate Curator of Collections
Earth and Mineral Science Museum & Art Gallery
Penn State University
*and*
Investigador Asociado, Departamento de Ornitologia
Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima


On Sat, Sep 3, 2022 at 2:16 PM Nadja Pöllath <poellath at snsb.de> wrote:

> Dear all,
>
> this is my first post to nhcoll listserve – so please bear with me, if I
> am not following the conventions of this list.
>
>
>
> I am a curator at a collection housing archaeological animal bones and
> modern reference specimens. With the energy crisis, the Bavarian state
> ordered that the heating system in the collection shall only be working
> before room temperature drops below 0°C. According to the Preventive
> Conservation ‘bible’ temperatures in storage rooms generally should not
> drop below 15°C. I’d like to hear about the guidelines regarding room
> temperature limits in comparable collections.
>
>
>
> More critical for archaeological and subfossil bones apparently are low RH
> values. As RH and temperatures are dependent variables, it would be good to
> know at which RH values damages are induced.
>
>
>
> Many thanks,
>
> Nadja
>
> (Staatssammlung für Paläoanatomie München, Staatliche
> Naturwissenschaftliche Sammlungen Bayerns)
>
>
>
>
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