Denatured alcohols

Jill Gregory <jitterbugging.jg<-at->gmail<.>com> writes

>Following my previous post regarding the application process for a
>licence to purchase Industrial Denatured Alcohol (IDA) from HMRC in
>the UK, I thought it might be useful for other conservators also
>looking to get a licence to know the outcome.
>...
>
>CDA (which now actually has a new recipe as of July 2013 of 100
>parts ethanol, 3 parts isopropanol and 3 parts methylethylketone and
>denatonium benzoate) could in theory be suitable for conservation,
but ...

Thanks Jill for outlining the most recent components of IDA versus
CDA. I would suggest against using CDA for any form of biological
preservation: the MEK content has been found to deteriorate both
specimens and containers in the fairly short term.  The D. Benzoate
(Bitrex) being an aromatic compound may also have long-term
destructive effects but nothing yet has been proven.  There was also
a brief mention, some years ago, that IPA (isopropanol) could
gradually denature chitin--a carbohydrate complex found in
arthropods but I no longer have any reference for this. So if any
regulating body gets a bit awkward about this (they have to make
sure), always bear these facts in mind.

Simon Moore MIScT, RSci, FLS, ACR
Conservator of Natural Sciences and Cutlery Historian,


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                  Conservation DistList Instance 28:40
                  Distributed: Sunday, March 22, 2015
                       Message Id: cdl-28-40-001
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