Alternative to xylene

Alan Phenix <aphenix [at] getty__edu> writes

>In the context of finding safer alternatives to xylene, for use with
>B  72 as a retouching medium for easel paintings, over 20 years ago I
>suggested the glycol ether 1-methoxypropan-2-ol CAS #107-98-2) as
>one possibility.  This cannot be regarded as harmless, with European
>occupational exposure limits (WELs in the UK) of 100ppm/ 375 mg per
>m3; but it is appreciably less hazardous than xylene (UK WEL 50ppm/
>220 mg per m3). And 1-methoxypropan-2-ol is a doubly-functional
>oxygenated solvent, which might mean that it is too 'active' for use
>in certain applications on certain objects on account of risk to the
>original material.

and Stephen Koob <koobsp [at] cmog__org> writes

>Besides the question of toxicity, the question of solvent choice
>seriously affects the Tg and applicability (as has been mentioned).
>But what has not been noted, is how the solvent choice also affects
>the viscosity.

I agree with Stephen and Alan here, there are other alternatives to
Propylene glycol monomethyl ether (PGME). You should keep in mind
that it is used as a solvent for cellulose, acrylics, dyes and inks,
so you must know the characteristics of any substrate you are using
it on.

While it has a low toxicity you must be knowledgeable of what low
means, as this solvent targets liver tissue.  Your specific health
limitations and susceptibility are important.

For details see

    <URL:http://oehha.ca.gov/air/chronic_rels/pdf/107982.pdf>

It is also a Peroxidizable Compound.

Niccolo Caldararo
Director and Chief Conservator
Conservation Art Service


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                  Conservation DistList Instance 25:40
                  Distributed: Saturday, March 3, 2012
                       Message Id: cdl-25-40-004
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