[NHCOLL-L:4486] Re: Mould on fossils
Moore, Simon
simon.moore at hants.gov.uk
Tue Sep 1 10:14:46 EDT 2009
Just to put my pennyworth in! I also concur that alcohol is the best
neutraliser of mould and that gentle swabbing will gradually remove all
traces of mycelial growth. I would not use any form of bleach no matter
how carefully, chloride/chlorite ions and geology specimens are not
happy partners and may lead to different problems in the future,
especially in RH-fluctuating situations!
Without wishing to open another can of worms but if some of the growth
was added to Schiff Reagent (aka Feulgen's solution = leuco-basic
fuchsin) wouldn't that give a magenta colour if it were fungal and
presumably a negative reaction if mineral?
With all good wishes,
Simon Moore, MIScT, FLS, ACR,
Senior Conservator of Natural Sciences.
Hampshire County Council,
Department of Culture, Communities and Rural Affairs,
Museums & Archives Service,
Chilcomb House, Chilcomb Lane,
Winchester SO23 8RD. UK.
Internal 8 327 6737
01962 826737
http://www.hants.gov.uk/museum/biology
________________________________
From: owner-nhcoll-l at lists.yale.edu
[mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of cahawks at aol.com
Sent: 01 September 2009 12:37
To: simmons.johne at gmail.com; annm at austin.utexas.edu
Cc: Sally.Shelton at sdsmt.edu; hfourie at nfi.museum; nhcoll-l at lists.yale.edu
Subject: [NHCOLL-L:4485] 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 <http://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 <http://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
--
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