Silica gel

Paul Harrison <paulehar [at] netvigator__com> writes

>I heard on the British archaeology discussion list of work conducted
>at the Institute of Archaeology, that the indicating part of
>blue/pink silica gel, the cobalt chloride should be treated with
>care, as it is a potential carcinogen by inhalation. ...

I would like to announce that there is a new indicating silica gel
which can be used as a replacement for the potentially carcinogenic
blue/pink silica gel: It is called "Orange silica gel" and shows a
nice colour shift from yellow-orange to red when adsorbing water
vapour. You can find further details
<URL:http://www.cwaller.de/esili.htm>. There are even other types of
indicating silica gel with colour shifts from yellow to green or
from orange to colourless. In general, it is sufficient to add 10%
of indicating silica gel to non-indicating silica gel.

Christoph Waller
Long Life for Art - Materials for Preventive Conservation
+49 7665 94 03 90
Fax: +49 7665 94 03 91


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                  Conservation DistList Instance 14:17
                Distributed: Tuesday, September 12, 2000
                       Message Id: cdl-14-17-005
                                  ***