Hydrogen peroxide as cleaning agent

Franklin Shores <fshores [at] covad__net> writes

>Valinda Carroll <vcarroll [at] cwf__org> writes
>
>Daniel-Harry Steward <posterdoctor [at] msn__com> writes
>
>>>I use a solution of hydrogen peroxide to clean paper surfaces. ...
>>...
>>Let me add that light bleaching, which is a milder form of peroxide
>>bleaching also generates a lot of acids.  A light bleaching bath
>>with calcium hydroxide dropped from pH 8 to pH 5 in four hours under
>>a UV-filtered light bank in our lab.
>
>I would just like to add that it is not the light bleaching that is
>causing the pH drop as much as it is the acid in the paper being
>washed.

I think that Franklin Shores missed the point of my posting. The
objects in question were washed for several hours in deionized water
conditioned with calcium hydroxide prior to light bleaching.  Water
soluble acids should have been significantly diluted if not
completely neutralized prior to the bleaching process. In mentioning
this treatment, I was simply trying to advocate thorough washing
*after* any bleaching treatments.

Referring to hydrogen peroxide as a cleaning agent, the author of the
original hydrogen peroxide query showed a lack of awareness of the
risks of using oxidizing agents for conservation treatment.  I know
that there is a popular mythology out there about the harmlessness
of hydrogen peroxide and light bleaching. Even reducing agents,
which could be beneficial to cellulose, may adversely affect some
inks, paints, etc. All oxidizing bleaches should be considered
restoration, rather than conservation, because they do not enhance
the longevity of the the object.

Valinda Carroll


                                  ***
                  Conservation DistList Instance 16:6
                  Distributed: Tuesday, July 16, 2002
                        Message Id: cdl-16-6-004
                                  ***