Mold

Nicole Prawl <nicoleprawl_234<-at->hotmail<.>com> writes

>Recently we had an outbreak of mold in one of our main reading
>rooms. It was controlled for a while and then it came back. ...

In order to give a useful response, it would be very helpful to know
where the library is situated and what kind of building it is.  What
is an appropriate solution in one climate will not be appropriate in
another.

First of all, you need to monitor the environment in the reading
rooms and the stacks, both day and night.  66% relative humidity is
not necessarily excessive, particularly if this is only for short
periods.  It is important to know how much fluctuation is caused by
switching the air conditioning off at night: this may be causing
very large changes in temperature and relative humidity.  If this is
the case, bringing in dehumidifiers may not be the best solution to
combating mold.  Dehumidifiers are most useful where there is a
finite source of moisture, for example when drying out an area that
has been affected by a flood.  If moisture is continuously coming
into the building from outside they may not achieve much.
Encouraging air circulation will certainly be helpful; you need to
check that there are no dead spots where the air is static.

Finally, you ask how often the shelves should be cleaned--the answer
is as often as necessary.  It all depends on how rapidly dust
accumulates.  If you can see a visible build-up of dust, it is time
to clean the shelves.

Barry Knight
Head of Conservation Science and Research
The British Library
London


                                  ***
                  Conservation DistList Instance 27:19
                Distributed: Wednesday, October 30, 2013
                       Message Id: cdl-27-19-005
                                  ***