Soot and odour removal after a fire

Reni Teygeler <rene.teygeler [at] wxs__nl> writes

>Does anyone have any experience in removing soot and the pungent
>odour from monographs after they have been recovered from a fire?

This is little more than speculation, but intuition suggests that a
low pressure atmosphere might be conducive to odour reduction for
fire damaged materials. Zeolites are in common use in conservation,
they are sometimes used for cleaning poultices on stonework and are
present in the white version of a range of absorptive papers and
boards used in the archive/museum world. The other material employed
is activated charcoal. My understanding is that these materials form
molecular traps. This is fine once the material to be removed is
free of the object, but how to encourage it to leave? By their
nature, the chemical species which we can smell are volatile. If the
surrounding pressure is reduced, the relative vapour pressure of the
volatiles increases. This provides the required gradient. By the use
of molecular traps and flushing a low pressure chamber with new air
it might be possible to expedite the process of deodourisation. Low
pressure (not vacuum) bagging might be an easier and cheaper low
volume alternative. If brushes are being used to remove smoke
particles, it is wise to use an industrial type downdraught table
which exhausts via either a HEPA (0.3 micron) filter or to the
outside air. At the very least use a vacuum cleaner with a HEPA
filter and a mask. After gross cleaning with brushes etc, use a
cleaning putty which will remove particles without re-distributing
them.

I have heard of lavender oil being suggested to mask unpleasant
smells; a cover up job? Ozone is  highly oxidising and toxic.
Oxidisation is one of the main mechanisms of decay, need one say
more?

Mark Hingley
Conservation Section
Norfolk Record Office
Norwich
England


                                  ***
                  Conservation DistList Instance 16:19
               Distributed: Thursday, September 12, 2002
                       Message Id: cdl-16-19-005
                                  ***