[Nhcoll-l] use of containers made from general purpose polystyrene ( GPPS ) in dry collection

[Callomon,Paul]

The main issue with polystyrene in terms of archival storage is that its formula is not fixed. The makers vary the proportions of certain plasticizers to maintain uniform flow in the molds by compensating for weather conditions. It does offgas a tiny amount, but nothing inimical to biological collections as far as we know.
We have used clear polystyrene for about 30 years now, and it has generally proven very stable. I've seen yellowing and crazing in some old polystyrene boxes in collections we have acquired, but they were usually lower-grade commercial packaging boxes (playing card boxes, for example) rather than purpose-made storage boxes. The yellowed ones tend to have spent long periods in hot, high-humidity environments too.
We have had more problems with deterioration of PTFE than with polystyrene, and the former is recommended by most museum people as stable.


Paul Callomon
Collection Manager, Malacology, Invertebrate Paleontology and General Invertebrates
________________________________
Academy of Natural Sciences of Drexel University, Philadelphia
callomon at ansp.org Tel 215-405-5096 - Fax 215-299-1170

________________________________
From: nhcoll-l-bounces at mailman.yale.edu [nhcoll-l-bounces at mailman.yale.edu] on behalf of Kareen Schnabel [Kareen.Schnabel at niwa.co.nz]
Sent: Monday, May 05, 2014 9:20 PM
To: nhcoll-l at mailman.yale.edu
Subject: [Nhcoll-l] use of containers made from general purpose polystyrene ( GPPS ) in dry collection

Good afternoon.
We are considering containers to be used in our dry specimen collection (marine invertebrates) and are tempted by inexpensive clear boxes made from general purpose polystyrene ( GPPS ).

Does anyone have experience with the use of this material in collections?

Suitability for long-term storage?

Is pH a concern?

Thanks for your help,
Kareen

Dr Kareen Schnabel
Marine Biologist
Invertebrate Collections Manager
+64-4-386-0862 | 301 Evans Bay Parade, Greta Point, Wellington | www.niwa.co.nz<http://www.niwa.co.nz>
[NIWA]<http://www.niwa.co.nz>



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