Ethafoam

Kasey Brewer <kbrewer [at] royalbcmuseum__bc__ca> writes

>We seem to have a large quantity of Ethafoam in artifact storage
>areas that is deteriorating.  It still appears sound, but if one
>presses a finger into it, the product compacts and crushes, leaving
>a hole where the finger was inserted.  It also leaves a white powder
>on the finger and surrounding areas.  I believe, but am not 100%
>sure, that this Ethafoam was purchased about 15 years ago when there
>was a large storage project underway that included making custom
>Ethafoam inserts for a huge number of drawers and shelving units.
>
>I contacted Dow Canada to enquire about the problem and was told
>that this was the first they have heard of it.  I asked if the
>problem could be associated with a change in blowing agent,
>instigated by the move away from CFC's around that time.  The
>representative emphatically stated that the blowing agents, several
>of which have been used over the years, are all inert and should not
>cause any breakdown of the polyethylene.  I asked if they had
>subcontracted out the manufacture of Ethafoam at some point, and
>perhaps lost some control over the production methods and was told
>that manufacture of Ethafoam has never been farmed out.  All they
>could suggest is that we had purchased something marketed as
>Ethafoam, but which was, in fact, another product. ...

It sounds to me that what you have got here is not Ethafoam at all,
but a polyurethane foam.  This could well deteriorate in the way you
describe over a period of 15 years.  It could also be emitting acids
as it degrades, which could be the cause of the corrosion you are
seeing on the hand tools.

I suggest you get an analysis done, to find out what the foam is,
and also send a sample to Dow.  Whatever the cause of the problem,
you'll need to think about the impact on your collections, as it
will certainly get worse, not better.  How many drawers and cabinets
are involved?  How much work would be involved in replacing the
foam?

Barry Knight
Head of Conservation Research
The British Library
96 Euston Road
London NW1 2DB


                                  ***
                  Conservation DistList Instance 19:13
                 Distributed: Friday, September 2, 2005
                       Message Id: cdl-19-13-008
                                  ***