[NHCOLL-L:4482] Re: Mould on fossils

[John E Simmons]

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 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:* 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., pyrite 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 the fossil
> plants in the same basement storeroom?
>
>
>
> Heidi
>
> Dr H. Fourie
> Curator: Vertebrate Palaeontology
> Transvaal Museum
> Tel: 012 3227632
>
>
>
>
> --
>



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