Electron beam irradiation

Here at the Smithsonian Institution Libraries Preservation and
Exhibition Services Department we have just received our first two
pieces of first class mail since early October, and I believe our
first two pieces of irradiated mail.  The two envelopes contained
photocopies of hygrothermograph charts, which we receive on a
regular basis from one of our branch libraries.

The envelopes postmarked Nov. 14 and Nov. 15 were quite yellow and
the tape used to seal it was darkened and wrinkled.  The photocopies
inside the envelopes were also yellow and in the envelope marked
Nov. 14 the toner of the photocopies, where they were folded in on
themselves, had fused together.

The paper of both the envelopes and the photocopies seems to be
quite brittle, the top of the Nov. 14 envelope shattered when we
tried to tear it open and a corner of a photocopy broke off after 2
double folds.  The Nov. 15 envelope appears to be in slightly better
condition but it is still noticeably yellow and brittle. Photocopies
that we received previous to this appear completely normal and the
library has always used standard, pH neutral, photocopy paper.

The information prepared by SCMRE and posted on their web site did
say "materials of cellulosic composition, especially plant fibers
and paper, will be quite seriously affected."  But I must say that
seeing an actual sample is quite a dramatic demonstration of the
damage inflicted by irradiation.

    **** Moderator's comments: See Ann B. N'Gadi's post in
    Conservation DistList Instance: 15:37 Monday, November 12, 2001

My questions to the list therefore are: Have others encountered
these results with irradiated mail?  Has the practice of irradiating
mail changed any procedures?  In particular for libraries, how has
this affected your Inter Library Loan program?

Eliza Gilligan
Book Conservator
Preservation and Exhibition Services Department
Smithsonian Institution Libraries
SISC Rm 2H7
Washington DC 20560-0806
202-357-1486


                                  ***
                  Conservation DistList Instance 15:47
                 Distributed: Thursday, January 3, 2002
                       Message Id: cdl-15-47-001
                                  ***