[NHCOLL-L:3294] RE: Gallon Size Clear Plastic Containers

Thu Jan 18 10:09:00 EST 2007

The Canadian Museum of Nature did some experiments with different jars and seals.  Our tests of polyethylene terephthalate (PET) jars indicated an increase in concentration of a 70%v/v ethanol solution when stored at a mean RH of about 35%.  This must be a result of a good mechanical seal and a higher permeability to water than to ethanol.  PET, also marketed as Mylar, is recognized as a stable material in many dry conservation applications such as document encapsulation and some containers.   These reports of 10-20 exposures to fluids showing no obvious problems are encouraging.  Our results on ethanol barrier effectiveness and concentration increases were most interesting but were not pursued further - too many most interesting roads to follow.  I recommend 1) seeking the advice of a polymer chemist (e.g., Scott Williams, CCI) on the likely long-term behavior of alcohol immersed PET and 2) testing a sample (minimum 10, better 30) of any proposed jars to determine leakage rate and concentration change characteristics before committing budget and staff time to introducing a new type of jar.  If well designed, that testing can be completed over 3 to 6 months using just a few days of staff time.

Rob

Robert Waller, Ph.D.

Chief, Conservation

Chef de conservation 

Musée canadien de la nature/Canadian Museum of Nature

C.P. 3443, Succ. D              /P.O. Box 3443, Stn D

Ottawa, ON

K1P 1P4 

Tel.:  (613)566-4797

Fax:  (613)364-4027

rwaller at mus-nature.ca

-----Original Message-----
From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Erik Åhlander
Sent: Thursday, January 18, 2007 6:38 AM
To: nhcoll-l at lists.yale.edu
Cc: jass at mpm.edu
Subject: [NHCOLL-L:3293] RE: Gallon Size Clear Plastic Containers

Did the alcohol concentration keep stable also? Some friends (commercial ecology investigators) kept about 10000 ethanol samples in plastic bottles. After some 10-15 years they realized that although the levels in the jars was OK the concentration was much lower through diffusion through the plastic. It was quit costly to refill the collection. No, I don't know what kind of plastic.

* * * * * * * * * * * * * * * * * * * * * *
Erik Ahlander, Collection Manager - Fishes
Swedish Museum of Natural History
(Naturhistoriska riksmuseet)
Section for Vertebrate Zoology
(Frescativagen 40)
P.O. Box 50007; S-104 05 STOCKHOLM, Sweden
Phone +46 8 51954118; Fax +46 8 51954212
email: erik.ahlander at nrm.se
* * * * * * * * * * * * * * * * * * * * * *

	-----Original Message-----
	From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu]On Behalf Of HJ Walker
	Sent: Thursday, January 18, 2007 4:09 AM
	To: CAHawks at aol.com; jsimmons at ku.edu; delre at mpm.edu; nhcoll-l at lists.yale.edu
	Cc: jass at mpm.edu
	Subject: [NHCOLL-L:3292] RE: Gallon Size Clear Plastic Containers

	Hello All,

	I've had a small experiment going with both isopropanol and ethanol in PETE containers for over ten years.  This plastic has no cracks and is still pliable.  Some Mexican friends have had these results for 20 years.

	Cheers,   H.J. 

		Hi Christine,

		I agree with John, PET is a good alternative. Gaylord makes straight-sided PET containers for fluid-preserved specimens, but doesn't list a gallon-size on their Web site. You might contact Christine Allen directly to see what she can find for you Christine.Allen at gaylord.com <mailto:Christine.Allen at gaylord.com> .

		Cathy

		In a message dated 1/17/2007 3:58:02 P.M. Eastern Standard Time, jsimmons at ku.edu writes:

		Christine,

			You might consider PET containers as an alternative-less oxygen permeance, clearer, more durable, and available in many sizes. I have seen gallon size PET-you might check with Gaylord.  Also, check out their large polycarbonate containers.

			--John

			John E. Simmons

			Collections Manager, Natural History Museum & Biodiversity Research Center

			and

			Director, Museum Studies Program

			University of Kansas

			1345 Jayhawk Boulevard

			Lawrence, Kansas 66045-7561

			Telephone 785-864-4508

			FAX 785-864-5335

			jsimmons at ku.edu <mailto:jsimmons at ku.edu> 

			www.nhm.ku.edu/herpetology <http://www.nhm.ku.edu/herpetology> 

			www.ku.edu/~museumst <http://www.ku.edu/~museumst> 

________________________________

			From: owner-nhcoll-l at lists.yale.edu [mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Del Re, Christine
			Sent: Wednesday, January 17, 2007 2:33 PM
			To: nhcoll-l at lists.yale.edu
			Cc: Jass, Joan
			Subject: [NHCOLL-L:3288] Gallon Size Clear Plastic Containers

			we are in search of clear plastic (polypropylene preferred) containers for the storage of alcohol collections.  Can anyone provide a lead for such containers before we broaden our so far successful search?

			many thanks for any information that you can provide, Chris

			Christine Del Re                Voice:  (414) 278-2780
			Senior Conservator              Fax:    (414) 278-6100
			Milwaukee Public Museum e-mail: delre at mpm.edu
			800 W. Wells St.
			Milwaukee, WI  53233-1478

		Catharine Hawks

		Conservator

		2419 Barbour Road

		Falls Church VA 22043-3026 USA

		t/f 703.876.9272

	-- 

	H.J. Walker, Jr.
	Scripps Institution of Oceanography
	University of California, San Diego  0208
	La Jolla, CA   92093-0208
	USA             hjwalker at ucsd.edu
	phone:858-534-2199   fax:858-534-5306

	Campus street  address for FedEx, UPS, DHL:
	8675 Discovery Way, 224 / 231 Vaughan Hall
	La Jolla, CA   92037

	SIO Marine Vertebrates Collection website:
	http://collections.ucsd.edu/mv/

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