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Subject: Crystal identification

Crystal identification

From: Mary Ann S. Tyrrell <20676mat>
Date: Tuesday, November 2, 1993
The Michigan State Univ. Libraries' Periodical/Microforms unit has
discovered an unidentified chemical in the bottom drawer of several
microfiche cabinets.  The cabinets were made by Remington Rand and call
themselves "Aristocrat."  We have also found a single piece of
documentation that may belong to the same cabinets.  This piece of paper
has no manufacturer's name on it, but the code at the bottom says
"RRNT-13281  PC 37020."  I take the RR to mean Remington Rand.

The header on the paper says "Film Filing Cabinets #26164 & #26159/
Instructions Relative to Chemical Solution/ For Use In the Six Hard
Rubber Trays of Bottom Drawer."  It describes the hard rubber trays with
four baffle plates found in the bottom drawers and goes on, "The
chemical mixture to be placed in each tray is as follows: one-half pint
of water added to approximately two pounds of humidifying chemical
crystals.  This mixture gives a solution in which there is an excess of
crystals.  It is important that an excess of crystals be maintained in
the solution so that it will absorb excess moisture from the air in the
cabinet when the air is excessively humid.... an excess of crystals...
will maintain the air in the cabinet at a relative humidity of
approximately 50% regardless of the relative humidity of the air in the

Hiram Davis, our Director, was the person who found the trays. He called
the MSU Office of Radiation, Chemical & Biological Safety (ORCBS) to
identify and dispose of the chemical.  The ORCBS officer would rather
that the Library try to identify the chemical before they analyze it.
The residue in the trays is crystalline, dark red, the color of dried
blood in fact, with an orangish scum up the sides of each of the nine
sections in each tray.  The scum also appears crystalline to the naked
eye, but does not throughout have the same glitter and large crystal
formation as the solid residue of dark red.

I spoke to Bob Mottice of UMI and Steve Dalton at NEDCC and both believe
that the color would indicate a silica gel.  But as the residue is not
the 'faded pink' described for saturated 'Blue indicating silica gel,'
and the Main Library is, if anything, excessively dry for most of the
year, I would appreciate a reply from list members who may remember such
apparently ill-fated early attempts at environmental control.  The
specific question the ORCBS officer would like answered is, besides the
identification of the chemical, whether it is considered a hazardous
waste.  I believe, however, that once the chemical is identified, ORCBS
should be able to search their own files for the relevant Material
Safety Data Sheet.

Mary Ann Tyrrell
Head, Preservation Dept.
MSU Libraries
(517) 336-3632

                  Conservation DistList Instance 7:37
                 Distributed: Friday, November 5, 1993
                        Message Id: cdl-7-37-003
Received on Tuesday, 2 November, 1993

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