Yellowing of polyethylene bags

Laura H. Nightengale <lnightengale [at] mail__utexas__edu> writes

>Many of our artifacts are curated in a climate-controlled room in
>very tight cabinets. Within the cab's many of the individual
>artifacts are enclosed in zip-top 4 mil thick polyethylene bags.
>Over the years we have noticed that some of the bags and the paper
>tags inside them have turned a yellow/green, especially, but not
>limited to, where the artifacts are touching them. This process can
>take as little as 4 months.

I remember when the issue of yellowing of polyethylene bags (and
perhaps also the cloth items stored in them) first came up.  It was
soon after permanent press textiles were introduced to the market. I
have forgotten who finally solved the mystery, but it turned out to
be a reaction between the treated clothing items and the bags they
were shipped or stored in. This was a big surprise to the chemists
who had introduced the treatment to the market.  As I recall, the
solution was not to bag the items.

Ellen McCrady
Abbey Publications, Inc.
7105 Geneva Dr.
Austin, TX  78723
512-929-3992
Fax: 512-929-3995


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                  Conservation DistList Instance 15:65
                  Distributed: Tuesday, March 26, 2002
                       Message Id: cdl-15-65-009
                                  ***