[NHCOLL-L:5742] Re: fluid preservatives

Wed Nov 30 15:53:12 EST 2011

Sue

There are no dangers to the specimens - bar the usual color loss etc.  The reasoning behind trying to find alternatives is due to its effects on the users - collections folks and those using the specimens.  Attempts are being made to find a less flammable solution that is easier to put on exhibit (without jumping through all the dangerous goods hoops) and is easier on the users in a classroom or educational setting where specimens are handled regularly.

In your setting, if the specimens are not handled regularly you are probably OK.  However, if specimens are handled regularly by children or other members of the public this may become a consideration.

Hope that helps

Andy

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 Andy Bentley
 Ichthyology Collection Manager
 University of Kansas
 Natural History Museum & Biodiversity Institute
 Dyche Hall
 1345 Jayhawk Boulevard
 Lawrence, KS, 66045-7561
 USA

 Tel: (785) 864-3863
 Fax: (785) 864-5335
 Email: abentley at ku.edu<mailto:abentley at ku.edu>        :
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From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Susan Gallagher
Sent: Wednesday, November 30, 2011 12:57 PM
To: A.J.van_Dam at lumc.nl; nhcoll-l at lists.yale.edu
Subject: [NHCOLL-L:5741] Re: fluid preservatives

Please excuse my ignorance as a list lurker.

Can someone elaborate on the danger of keeping specimens in ethyl alcohol? Am I correct in assuming this is safer by far than formalin?

Would there be much of an advantage to changing over to glycerol for use in a nature center setting? Our specimens are common items, and part of a teaching collection only - therefore not necessarily requiring the same kind of preservation as in a museum setting. They were initially preserved in formalin, then placed in ethyl alcohol. Loss of color doesn't seem to be much of an issue.

Thanks for any input.

Sue

********************************************************
Susan Gallagher, Chief Naturalist
Carbon County Environmental Education Center
151 East White Bear Drive
Summit Hill, Pennsylvania, 18250
(570) 645-8597
www.carboneec.org<http://www.carboneec.org>

Teaching a child not to step on a caterpillar is as important to the child, as it is to the caterpillar.
- Bradley Miller

.

From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of A.J.van_Dam at lumc.nl
Sent: Wednesday, November 30, 2011 5:37 AM
To: Couteaufin at aol.com; crissanen at museumca.org
Cc: nhcoll-l at lists.yale.edu
Subject: [NHCOLL-L:5739] Re: fluid preservatives

Dear Carolyn,

The safest and most reliable alternative to use is the alcohol "glycerol" in an end concentration of 65%, in use in our collections for about 100 years.

DMDMH, a formaldehyde releasing agent (used as low toxic alternative in cosmetic and personal care products), could also be an alternative but like Novec there is not yet a long track record. Know that the very expensive Novec does NOT replace the (hazardous) preservative inside the tissue, it should be seen as liquid embedding media / envelope fluid, like liquid paraffin.

Glycerol has extreme low vapor pressure, is low toxic (same NFPA health hazard rating as ethanol), flash point of 160 degrees Celsius (ethanol 13 degrees Celsius), preserves/revives (blood) color, no shrinkage when transferred in baths of increasing glycerol concentration.

Of interest might be our recently published paper (preprint of the Triennial Conference of ICOM-CC 2011, Lisbon):

A migration mechanism for transfer of sharks from ethanol to aqueous glycerol solutions

Ian D. MacLeod*
Western Australian Museum
Collections & Research Centre
Welshpool, Western Australia, Australia
ian.macleod at museum.wa.gov.au<mailto:ian.macleod at museum.wa.gov.au>

Andries J. van Dam
Leiden Museum of Anatomy
Leiden University Medical Centre
Leiden, The Netherlands
*Author for correspondence

Abstract
This paper presents a scoping study on the impregnation of glycerol into formaldehyde-fixed and aqueous-ethanol-preserved sharks. The weight increase and solution density changes were monitored in sequential baths of aqueous glycerol. Positive results included a return of the colour of the specimens, improved flexibility, and removal of alcohol from the body of the specimen and significant improvement of the original profiles and skin textures of the specimens.

Regards,

Dries

Andries J. van Dam, conservator

Museum of Anatomy
Leiden University Medical Center
Postal zone T7-P
P.O.Box 9600
2300 RC Leiden
The Netherlands
tel: +31 (0)71 526 9581
fax: +31 (0)71 526 8275
E-mail: A.J.van_Dam at lumc.nl<mailto:A.J.van_Dam at lumc.nl>
Visiting address: Hippocratespad 21, building 3

Associate scientist, Natural History Museum, London
http://www.nhm.ac.uk<http://www.nhm.ac.uk/>

Directory Board member ICOM-CC
http://www.icom-cc.org<http://www.icom-cc.org/>

Director Alcomon Company
http://www.alcomon.com<http://www.alcomon.com/>

________________________________
From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Couteaufin at aol.com
Sent: dinsdag 29 november 2011 23:59
To: crissanen at museumca.org
Cc: nhcoll-l at lists.yale.edu
Subject: [NHCOLL-L:5738] Re: fluid preservatives

Hi Carolyn,

I have never had firsthand experience with Novec, but it is an expensive fluid and has a high specific gravity so specimens float in it.  It has not been tested in the long term and I have a bad feeling about it.

Have you considered an alternative such as Dekafald (DMDM hydantoin)?  It acts as an ionic transfer agent using methylene bridges like formalin?

It also depends on what specimens are intended for display (vertebrate, invert, botanical &c)?  Glycol preservatives are still good in the short term (1 year or so) if the specimens have been properly fixed beforehand.

Also need to know what type of jars would be involved (glass, plastic)?

With all good wishes, Simon

Simon Moore MIScT, FLS, ACR,
Conservator of Natural Sciences,
20 Newbury Street,
Whitchurch RG28 7DN. UK
T. 01256 892335
www.natural-history-conservation.com<http://www.natural-history-conservation.co.uk/>

www.pocket-fruit-knives.info <http://www.pocket.fruit-knives.com/>

In a message dated 29/11/2011 00:13:09 GMT Standard Time, crissanen at museumca.org<mailto:crissanen at museumca.org> writes:
Dear list -
We are in the midst of a major gallery re-install, and there has been some discussion about putting wet specimens out as part of one of the new exhibits.  The question came up about whether there was a safer alternative to de-natured alcohol or formalin as a preservative - a fluid that wouldn't be quite as hazardous should something happen to the jar.  Doing a web search, someone came up with a 3M product: 3M Novec Engineered Fluid.  Does anyone have any experience with this product?  Do you have any advice concerning display of fluid preserved specimens?

Thanks,
Carolyn
Carolyn Rissanen
Registrar, Collections and Information Access
Oakland Museum of California
www.museumca.org<http://www.museumca.org/>
510-318-8490
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