Alternative to xylene

Alan Phenix <aphenix [at] getty__edu> writes

>Smadar Gabrieli <smadar.gabrieli [at] uwa__edu__au> writes
>
>>Raymond A. Spiteri <raymond.a.spiteri [at] gov__mt> writews
>>
>>>We are seeking a less hazardous alternative to xylene to be used in
>>>solvent mixtures and for dissolving acrylic resins like Paraloid B72
>>...
>
>In the context of finding safer alternatives to xylene, for use with
>B72 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.

I agree that polypropylene glycol methyl ether known also as Dowanol
PM is a great solvent for Acryloid B-72 and has similar properties
to ethanol in terms of toxicity, flammability, etc.  It has an
evaporation rate similar to xylene and makes nice coherent films. As
a consolidant for friable pigments it worked very well with less
darkening than with acetone.  It is also an excellent solvent for
old PVA emulsions.  It is readily available from industrial chemical
suppliers, though it is sold under many different names.

Linda Roundhill
Art and Antiquities Conservation, LLC
Woodinville, WA


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                  Conservation DistList Instance 25:39
                 Distributed: Friday, February 24, 2012
                       Message Id: cdl-25-39-004
                                  ***