Polypropylene storage boxes

Tim Edwards <sadete<-a t->hantsnet< . >hants< . >gov< . >uk> wrote:

>Does anyone have any views on polypropylene boxes for volume
>storage? ... I believe the material itself is sound
>but am concerned with its performance in a disaster situation eg.
>would it be likely to melt at temperatures at which paperboard
>enclosures would only char?

and

Gretchen Fulforth Stroh <gstroh1<-a t->swarthmore< . >edu> answered:

>I recently took a workshop sponsored by the Conservation Center for
>Art and Historic Artifacts.  They had done a disaster experiment
>involving setting on fire and then dowsing with water both the
>plastic and paperboard clamshell boxes.  Rather surprisingly, the
>plastic melted (no surprise there) and the items inside were ruined.
>The paperboard boxes held up rather well, some of the items inside
>were rather well protected, some got toasted a bit.  These boxes
>were storing "archival" items, and because they were "full" the
>inside contents seemed to be insulated better than those on the
>outside.  Thus, they recommended the paper board over the plastic.
>Are you in a position to conduct such experiments?

I too attended the CCAHA workshop, but came away with a few
additional thoughts and comments.  My observation was that it is
true, the polypropylene box did melt, and bonded into a gooey mess
with the contents, but it was only circumstantial in how the
test-fire burned that the paper box somewhat survived.  In *equal*
circumstances, the plastic would have melted as it did, and the box
would be totally burnt, with all the contents inside destroyed.  In
general, if actual fire reaches collections in either storage
container, it is bad news.  What struck me was how fast the
polypropylene ignited.  It appeared to ignite faster that the
blue-board box, but again, maybe circumstances.

The melted poly box had unburned objects inside in the end, but the
were irretrievable due to plastic melted all over.  The burnt
paper-based box had mostly burnt objects, but a few were barely
legible--but again, beyond repair in my opinion.

Then we throw (literally) water into the scenario.  Unburned poly
boxes kept small amounts of water out completely, but if deluged,
held water inside for a long time like a fish-bowl (therefore
seriously affecting potentially water-soluble media, but in general,
keeping the box contents intact, because the box remains rigid and
supportive).  Another thing which struck me was how, after exposure
to water, you could dry these boxes and they were perfectly
re-usable.  They also could be sent directly to freeze-drier with
contents intact.

Unburned blue-board boxes, on the other hand, soaked up any amount
of water and quickly lost their shape and were difficult to handle
and fell apart as heavy, wet paper will.  They _could_ be placed in
rescubes and the box and contents freeze-dried and items saved,
though.  Box definitely not re-usable.

I have thought a lot about the scenario presented at CCAHA, since a
major part of my teaching curriculum (Workshop taught now at 15
venues: "Preservation, Care and Rehousing of Three-Dimensional
Objects") is a discussion and presentation of the use of both
paper-based and fluted poly materials for boxes and mounts.  For me,
the jury is still out, and I'm not sure CCAHA ever did state which
they recommended over another, but it was a very useful
demonstration.  For me, the main objective is to prevent fire from
reaching collections.  Period.  Fire pretty much destroys, whether
things are housed or not, whether in paper or plastic.  Then, if we
are talking about water damage, and not fire damage, we have pro's
and cons to each method

A closing note on plastic materials:  we tried to get a straight
answer from the fire marshall present at the CCAHA workshop as to
whether or not he felt plastic materials posed a health hazard to
his crew, and if there were any reasons he would not enter a storage
area with a lot of plastic housings.  He immediately started to talk
about PVC, and the dangers, but never clearly answered our question.
but it was clear that they viewed anything plastic as very toxic,
whether it was relative inert polypropylene or polyethylene or
anything else.  This is another thing we should look into and think
about.

I would love to hear more comments on this subject, as we are seeing
more and more use of polypropylene in storage.  What are the
implications?

Lori van Handel
Director of Field Services/Assistant Conservator
Williamstown Art Conservation Center
225 South Street, Williamstown, MA  01267  USA
413-458-5741
Fax:  413-458-2314

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                  Conservation DistList Instance 11:41
                 Distributed: Friday, October 31, 1997
                       Message Id: cdl-11-41-003
                                  ***