Feedback sought for article on removing odor from books

James Druzik <jdruzik<-a t->getty< . >edu> writes

>... The reputation of CHC was damaged in the 1970's by user
>sensitivity to it.
> ...
>This asks a larger question.  Will deacidifying acidic papers reduce
>their susceptibility to mold under high humidity with or without
>enhanced air ventilation?  This is what we intend to investigate
>further in the next few years.

In response to your post about my comments on CHC I have to say that
I expected that you might contribute information about whether the
pH change might affect mold, etc., but since you mention the 1970
report on CHC here are my thoughts on it.

That post on the list was a bit tongue-in-cheek, but as for CHC or
cyclohexylamine carbonate, Langwell introduced this chemical as a
vapor phase treatment for books and paper in the 1960s.  His
publication on the chemistry and methods for use are in his article
in the Journal of the Society of Archivists, v. 3, n. 3, 1966.

Simply enough the CHC chemically combines with the acid fractions
present in the paper given ambient humidity and temperature
conditions.  The method never really was popular and became
out-of-fashion when Mervyn Ruggles published some rather poorly
designed experimental results comparing CHC with other
deacidification methods.

The CHC results were comparable to the other methods in initial rise
in paper pH, but fell to much lower levels after  artificial aging
equally 120 years.

Ruggles then reported tests with Barium hydroxide with two different
paper samples [n]either of which was the same type as used in the
CHC test (Cardinal sin of scientific method #1).  The results showed
similar increases as the CHC but no drop off.

However, when one examines the chart for Barium hydroxide you find
that initial aging profiles for deacidification curves are for 20
years not the 10 days reported for CHC and 108 days for the long
term tests not 120 years as for CHC. Thus unless the legends were
mistaken for the barium hydroxide (Cardinal sin of scientific method
#2), something was wrong with the experiment.  Nevertheless the
aging times should have been the same at any rate (Cardinal sin of
scientific method #3). Health concerns for CHC were also noted, and
thus CHC fell from use. Hope this helps.

>Also
>cyclohexylamine can combine to form chromophores on substrates which
>are strongly colored. I have seen it do this on coated papers.  I
>never went into it further but my speculation is that this was a
>binder interaction.

I've heard this stated before, that CHC can cause darkening or
staining, but no one has done any research on it.   T.B. Kahle used
CHC on a variety of books, papers, documents and he never reported
any coloration appearing and I never saw any occur during any of the
treatments I saw in his lab.  I am very interested in treatment
effects and durability of treatments over time (an example of my
research on this appears in the present issue of Studies in
Conservation, but on an entirely different subject) so if anyone out
there has good evidence on this one way or anther I'd be very
interested in hearing from  you.

Niccolo Caldararo
Director and Chief Conservator
Conservation Art Service

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                  Conservation DistList Instance 11:32
                  Distributed: Monday, October 6, 1997
                       Message Id: cdl-11-32-005
                                  ***