[NHCOLL-L:4491] Re: Mould on fossils

[John E Simmons]

If you can't reduce the relative humidity below 65% in the storage area, and
fans are not an option, you can try a micro-environment approach, such as
using silica gel to lower the RH inside containers or cabinets.

A good example of the application of micro-environments can be found in the
Museum of the Inca in Cuzco, Peru.  The museum is located in a large stone
building that gets very damp inside.  The supply of electricity is too
unreliable to use a dehumidifier, and in any case, as Cathy Hawks has
pointed out, using a dehumidifier in this situation would most likely damage
the walls of the building by drawing moisture through the walls at a greater
rate.  The museum uses the type of silica gel that changes color when
saturated.  The gel is used in both storage and exhibit cases.  A small
grant from a European foundation enabled the museum to purchase a good
supply of the silica gel and a small microwave oven to dry it when it
becomes saturated.

--John

On Tue, Sep 1, 2009 at 12:37 PM, Ann M Molineux <annm at austin.utexas.edu>wrote:

>  Heidi’s question is turning into a really interesting dialogue. In
> response to John’s and others excellent points I’ll add a bit more about our
> problems.
>
> We used the mild bleach only at the suggestion of our mycologist advisor
> and then very limited, where the fossils were shells, the shell portions
> were just dusted to remove the visible signs of mold. In the light of your
> feedback comments  we shall return to our former practice and rely on
> ethanol solution.
>
>
>
> We were, however, advised not to encase in plastic *if the specimens had
> to remain in the non-HVAC environment* because that can lead to other
> problems. This advice did seem reasonable as our own limited testing of T
> and RH inside plastic bags found an increase in humidity levels in the
> plastic bags if they were zipped, again this was in a non-HVAC environment
> in Texas. We have not yet tested T&RH in completely heat sealed bags  in non
> HVAC. We do encase in plastic in the HVAC zone.
>
>
>
> We were also advised to take specimens into sunlight but that was not
> feasible for us for many other reasons.
>
>
>
> Although we cannot remove all specimens to HVAC  conditions, we do remove
> infected individuals to isolate in our available HVAC space. In addition we
>  map those cabinets producing these specimens, [we have a GIS of the entire
> repository] and are tracking the outbreaks to see if there is a geographic
> pattern (repository position) to them or a geological pattern (composition).
> These are specimens that are very rarely handled and drawers are seldom
> opened.  We have been using fans, as mentioned in one response, and if the
> outbreak appears to be geographic we should be able to focus those fans more
> effectively.
>
>
>
> Are fans the only solution to this problem if you are unable to move all
> specimens into climate controlled environments?
>
>
>
> ann
>
>
>
> **********************************
>
> Ann Molineux,
> PhD
>
>
> Curator and Collections Manager, Non-vertebrate Paleontology
>
> Texas Natural Science Center, The University of Texas at Austin
>
> Phone: 512-232-5384,  FAX: 512-471-6090
>
> Web: http://www.utexas.edu.tmm/npl/
>
> Mailing addresss: Non-vertebrate Paleontology Lab, Building 122
>
> J. J. Pickle Research Campus, 10100 Burnet Road, Austin, TX 78758-4445
>
>
>
> *From:* cahawks at aol.com [mailto:cahawks at aol.com]
> *Sent:* Tuesday, September 01, 2009 6:37 AM
> *To:* simmons.johne at gmail.com; Ann M Molineux
> *Cc:* Sally.Shelton at sdsmt.edu; hfourie at nfi.museum; nhcoll-l at lists.yale.edu
> *Subject:* Re: [NHCOLL-L:4482] Re: Mould on fossils
>
>
>
> I concur with John. Mold, if that is what it is, is an indication of a
> fundamental problem in the environment. In general, you do not have mold on
> collections - certainly not widespread mold - unless you first have mold in
> the building fabric. Consequently, addressing the source of the problem
> (e.g., poor drainage around the building, whatever), is important.
>
>
>
> I, too, discourage the use of chlorine bleach on specimens. While this will
> theoretically kill mold, in reality, the fungi involved are part of the
> aeromycoflora and "killing" in this sense is at best a temporary and very
> localized solution. Use of 95% ethanol is certainly a better choice if HEPA
> vacuum still leaves you with persistent residues, and will do far less
> damage to the specimens.
>
>
>
> If the mold is pervasive in the space, you may need to consult with a
> professional mycologist specializing in mold abatement in buildings.
> Cleaning the specimens and leaving them in the same space will likely result
> in re-contamination. Also, avoid using dehumidifiers in subsurface spaces -
> these can actually exacerbate the problem if they are causing moisture to be
> pulled in through a porous building fabric. When you have a serious mold
> problem and there is no obvious localized source (a leak, for instance), you
> probably do need an expert to help mitigate the problem.
>
>
>
> Cathy
>
>
> -----Original Message-----
> From: John E Simmons <simmons.johne at gmail. com>
> To: Ann M Molineux <annm at austin.utexas.edu>
> Cc: Sally.Shelton at sdsmt.edu <Sally.Shelton at sdsmt.edu>; hfourie at nfi.museum<
> hfourie at nfi.museum>; nhcoll-l at lists.yale.edu <nhcoll-l at lists.yale.edu>
> Sent: Mon, Aug 31, 2009 11:03 pm
> Subject: [NHCOLL-L:4482] Re: Mould on fossils
>
> The underlying theme of all the messages that Heidi's post prompted is that
> mold is an indication of a problem in the storage environment--the
> appearance of mold means something has gone wrong.  Mold spores are around
> us all the time, but they only grow and spread as mildew when the
> environmental conditions are right.  The only way to prevent mold outbreaks
> is by controlling the environmental conditions the mold needs to grow.  Most
> mold needs a relative humidity of 65% or higher (a few species will grow at
> 55%) and a nutrient base.  If you have a situation where you cannot lower
> your RH below 65 (e.g., in the tropics) you may be able to prevent mold
> growth by improving air circulation (for example, with fans).
>
> When a mold outbreak occurs in a collection, the first question to ask is
> not how to clean it up, but rather, what caused the mold to start growing.
> A mold outbreak means something has changed in the storage environment that
> is not good for the collections.  The sudden appearance of mold may be the
> first evidence you see of more serious drainage or leakage problems.
> Determining where the mold is growing can provide clues to what is wrong and
> can help you establish cleanup priorities.  Mold must have a nutrient base,
> which is why mold growing on leather is a much more serious problem than
> mold that has spread over fossils (the mold will damage the leather faster
> than the fossils).  Isolate the affected specimens if you can (for example,
> in polyethylene bags) or affected area, then deal with cleanup.  At any
> rate, cleaning up the mold won't help unless you can fix the environmental
> problem, too.
>
> I do not recommend using bleach for cleaning mold from scientific
> specimens.  In general, it is much safer to lightly swab the surface of most
> specimens with cotton swabs dipped in 95% ethyl alcohol.  The alcohol will
> kill the active mold and evaporate quickly from the surface of the
> specimen.  Bleach will probably damage whatever it comes in contact with,
> and is harder to remove.  Before you clean any mold from the surface of a
> specimen, make sure that your cleaning procedure and cleaning chemicals will
> not cause worse damage than the mold already has.
>
> Good luck dealing with this problem, Heidi, and please let us know what the
> solution to your problem was.
>
> --John
>
> John E. Simmons
> Museologica
> 128 E. Burnside Street
> Bellefonte, Pennsylvania 16823-2010
> simmons.johne at gmail.com
> 303-681-5708
> www.museologica.com
> and
> Adjunct Curator of Collections
> Earth and Mineral Science Museum & Art Gallery
> Penn State University
> 19 Deike Building
> University Park, Pennsylvania 16802-2709
> jes67 at psu.edu
>
> On Mon, Aug 31, 2009 at 5:14 PM, Ann M Molineux <annm at austin.utexas.edu>
> wrote:
>
> Heidi,
>
>
>
> We have also noted instances of various molds on our historic Tertiary
> fossil collection located in a non-HVAC zone. Our Microbiology department
> verified that it was mold and appeared to be from common spores found in air
> and soil. According to them we would need specimen sterilization and sealing
> within moisture free chambers to completely protect them.
>
> In our situation that translated into gently dusting off the mold, light
> swabbing with a mild bleach solution (if the specimen could withstand such
> treatment), and transfer as many as feasible to our HVAC zone.
>
> We have limited space in the HVAC zone but we assigned this collection as a
> priority for any additional space when available. Luckily for us some
> additional space may shortly be available and we are currently searching for
> funding to achieve the transfer and upgrade. None of our specimens were
> plant fossils but we will go ahead and move our more important plant
> specimens currently stored in similar conditions,  into the HVAC zone.
>
> I think the take home message from our viewpoint was that this was a
> problem that had to be addressed if we wished to retain these very valuable
> early collections.
>
> Ann
>
>
>
> **********************************
>
> Ann Molineux,
> PhD
>
>
> Curator and Collections Manager, Non-vertebrate Paleontology
>
> Texas Natural Science Center, The Univ ersity of Texas at Austin
>
> Phone: 512-232-5384,  FAX: 512-471-6090
>
> Web: http://www.utexas.edu.tmm/npl/
>
> Mailing addresss: Non-vertebrate Paleontology Lab, Building 122
>
> J. J. Pickle Research Campus, 10100 Burnet Road, Austin, TX 78758-4445
>
>
>
> *From:* owner-nhcoll-l at lists.yale.edu [mailto:
> owner-nhcoll-l at lists.yale.edu] *On Behalf Of *Shelton, Sally Y.
>
>
> *Sent:* Monday, August 31, 2009 9:39 AM
>
> *To:* Simmons, John; hfourie at nfi.museum
>
>
> *Cc:* nhcoll-l at lists.yale.edu
>
> *Subject:* [NHCOLL-L:4477] Re: Mould on fossils
>
>
>
> I would also check to make sure that, as John says, this is not Byne’s
> “disease” or other mineral efflorescence. The scenario you describe does not
> sound like pyrite breakdown, but does suggest the possibility of mineral
> efflorescence.
>
>
>
> I hate to engage in shameless self-promotion and am not trying to do so,
> but here is a reference:
> http://www.nps.gov/history/museum/publications/conserveogram/11-15.pdf.
> This can affect fossil as well as Recent specimens.
>
>
>
>
>
> *Sally Y. Shelton, Collections Manager and Faculty Instructor*
>
> *Museum of Geology, O'Harra 307*
>
> *South Dakota School of Mines and Technology*
>
> *501 E. St. Joseph*
>
> *Rapid City, SD   57701*
>
> *phone 605.394.2487*
>
> *email Sally.Shelton at sdsmt.edu*
>
>
>
>
>
>
>
> *From:* owner-nhcoll-l at lists.yale.edu [mailto:
> owner-nhcoll-l at lists.yale.edu] *On Behalf Of *John E Simmons
> *Sent:* Monday, August 31, 2009 8:14 AM
> *To:* hfourie at nfi.museum
> *Cc:* nhcoll-l at lists.yale.edu
> *Subject:* [NHCOLL-L:4476] Re: Mould on fossils
>
>
>
> Are you positive that this is mold?  Mold needs a nutrient base to grow, as
> well as high humidity (>65% for most species).  There are very little
> nutrients on fossils, unless the mold is eating some organic-based
> coating.   You might be seeing a salt efflorescence or crystallization of
> minerals in the rock matrix (e.g., pyrit e disease) rather than mold--try
> scraping some off and looking at it under a microscope.
>
> --John
>
> John E. Simmons
> Museologica
> 128 E. Burnside Street
> Bellefonte, Pennsylvania 16823-2010
> simmons.johne at gmail.com
> 303-681-5708
> www.museologica.com
> and
> Adjunct Curator of Collections
> Earth and Mineral Science Museum & Art Gallery
> Penn State University
> 19 Deike Building
> University Park, Pennsylvania 16802-2709
> jes67 at psu.edu
>
> ---------- Forwarded message ----------
> From: *Dr Heidi Fourie* <hfourie at nfi.museum>
> Date: Sat, Aug 29, 2009 at 7:36 AM
> Subject: [NHCOLL-L:4474] Mould on fossils
> To: nhcoll-l at lists.yale.edu
>
> I've discovered mould growing on fossils we stored in our basement.  These
> are invertebrate fossils in blocks mounted in wooden frames.  Both the frame
> and fossil are covered in mould.  The mould is  whitish grey wooly and round
> in pattern.  It even grows on the Glyptal.
>
> My question is, what is the safest chemical to clean this with or is water
> and soap safest.  The storage room that it is going to has a very low
> humidity so I don't think the mould will reappear and how safe is th e
> fossil plants in the same basement storeroom?
>
>
>
> Heidi
>
> Dr H. Fourie
> Curator: Vertebrate Palaeontology
> Transvaal Museum
> Tel: 012 3227632
>
>
>
>
> --
>
>
>
>
> --
>



-- 
John E. Simmons
Museologica
128 E. Burnside Street
Bellefonte, Pennsylvania 16823-2010
simmons.johne at gmail.com
303-681-5708
www.museologica.com
and
Adjunct Curator of Collections
Earth and Mineral Science Museum & Art Gallery
Penn State University
19 Deike Building
University Park, Pennsylvania 16802-2709
jes67 at psu.edu
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