Biocides for stone

Can any stone conservators (or others) inform me of what type of
biocide to use on external stone to remove unwanted organic growth.
In the rare cases where l have had to use this l have been using
Wykamol Microtech Biocide 25X.  Is there anything better and greener
(if possible).

Vanessa Simeoni
Monuments Conservator
Westminster Abbey
London
UK



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                  Conservation DistList Instance 15:65
                  Distributed: Tuesday, March 26, 2002
                       Message Id: cdl-15-65-015
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