[Nhcoll-l] Phenolic lids in alcohol

[CAHawks at aol.com]

One problem with phenolic caps is that the polymer probably contains  
formaldehyde. Exposed to trace formaldehyde from fixation of specimens  
subsequently stored in alcohol, the polymer will deteriorate (that old, "like  
dissolves like" concept). Any specimen fixed in formalin and later transferred  to 
alcohol should have some unfixed formaldehyde in the alcohol given that  
fixation is a equilibrium reaction. 
 
Cathy
 
Catharine  Hawks, PA-AIC, FIIC
Conservator, NMNH
(h) 703.876.9176
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hawksc at si.edu  



In a message dated 6/13/2014 5:22:28 P.M. Eastern Daylight Time,  
halford at sfu.ca writes:

 
When phenolic capped vials are stored as you describe the caps can expand  
over time and eventually fall off, potentially leading to lots becoming 
mixed  in the bottom of the holding vessel.  It's better to discard the cap and  
replace it with a loose plug of cotton.  Face the  neck of the vial  up so 
no air bubbles become trapped.


Steve.



Steve Halford (_halford at sfu.ca_ (mailto:halford at sfu.ca) )
Museum  Technician (Retired)            
Department  of Biological Sciences
Simon Fraser University





On Fri, Jun 13, 2014 at 10:28 AM, Callomon,Paul <_prc44 at drexel.edu_ 
(mailto:prc44 at drexel.edu) > wrote:


 
Folks, 
We have noticed that in cases where a phenolic resin cap  is immersed in 
alcohol (70-80% ethanol) for long periods (such as when a  vial with a sample 
is included in a larger alcohol-preserved lot) the  alcohol becomes 
discolored. I presume the resin is leaching something. Does  anyone know of any 
published work on this? 
Paul Callomon
Collection Manager, Malacology,  Invertebrate Paleontology and General 
Invertebrates 
  
____________________________________
 
Academy of Natural Sciences of Drexel  University, Philadelphia 
1900 Benjamin Franklin Parkway,  Philadelphia PA 19103-1195, USA
_callomon at ansp.org_ (mailto:callomon at ansp.org)  Tel _215-405-5096_ 
(tel:215-405-5096)  - Fax _215-299-1170_ (tel:215-299-1170)  



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