<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">Nadja,</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">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 <i>Preventive Conservation: Collection Storage</i>, 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.<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">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.</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">There are a number of publications available that address these issues. Three that are available for free download include:</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:#000000">
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">Padfield et al. 2013, Low energy
museum storage<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><a href="https://www.conservationphysics.org/storage/low-energy-museum-storage.html" style="color:rgb(5,99,193);text-decoration:underline">https://www.conservationphysics.org/storage/low-energy-museum-storage.html</a><span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">Maekawa and Garcia Morales
2006-Los-cost climate control system for museum storage facility<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><a href="https://www.getty.edu/conservation/our_projects/science/climate/valle_de_guerra_PLEA_2006.pdf" style="color:rgb(5,99,193);text-decoration:underline">https://www.getty.edu/conservation/our_projects/science/climate/valle_de_guerra_PLEA_2006.pdf</a><span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif">Kerschner 2008-Providing safe and
practical environments for cultural property in historic buildings<span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><a href="https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.568.1438&rep=rep1&type=pdf" style="color:rgb(5,99,193);text-decoration:underline">https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.568.1438&rep=rep1&type=pdf</a><span></span></p>
<p class="MsoNormal" style="margin:0in;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span> </span></p>
</div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)">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.<br></span></span></font></div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)"><br></span></span></font></div><div><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)">Glad to see you posting to nhcoll!!</span></span></font></div><div><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)"><br></span></span></font></div><div><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)">--John</span></span></font></div><div><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)"><br></span></span></font></div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif"><span class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;color:rgb(0,0,0)"></span>John E. Simmons<br>Writer and Museum Consultant</span></font></div><div dir="ltr"><font size="2"><span style="font-family:tahoma,sans-serif">Museologica<br><i>and</i><br>Associate Curator of Collections<br>Earth and Mineral Science Museum & Art Gallery<br>Penn State University<br><i>and</i><br>Investigador Asociado, Departamento de Ornitologia<br>Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima</span></font><br></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Sep 3, 2022 at 2:16 PM Nadja Pöllath <<a href="mailto:poellath@snsb.de">poellath@snsb.de</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg5974690428037347884"><div lang="EN-GB"><div class="m_8346938320509941933WordSection1"><p class="MsoNormal">Dear all,<u></u><u></u></p><p class="MsoNormal">this is my first post to nhcoll listserve – so please bear with me, if I am not following the conventions of this list.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">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.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">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.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Many thanks,<u></u><u></u></p><p class="MsoNormal">Nadja<u></u><u></u></p><p class="MsoNormal"><span lang="DE">(Staatssammlung für Paläoanatomie München, Staatliche Naturwissenschaftliche Sammlungen Bayerns)<u></u><u></u></span></p><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p></div></div>_______________________________________________<br>
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