Edited 14 Dec 2015 23:46, 6 years ago, edited by Aaron

Okay, so if you're talking about polyurethane then the news is a little worse.

Avoid prolonged exposure to IPA.

(I can be properly nerdy on this topic)

Earlier in the year I ran data and numerical analysis on a question very similar to this for a friend of mine looking to patent a new recipe of aliphatic polycarbonate polyurethane. Intended for use in the medical field, the primary property of interest looked at was it's ability to withstand exposure to oxidising and reducing agents, saline solutions and EtOH.

We were time exposure testing the urethane in >70% solution EtOH and IPA at up to 37C temperatures, the good news is his new polymer was pretty good, the bad news is the general samples it tested against were not that good. (Read up on ethanol locks for sterilisation of catheters as to why).

I no longer have the data, but I do recall that some polyurethanes were distorted dimensionally, and in cross-sectional shape, and also often in colour against the control after as little as 10 minute exposure times.

As an aside, whilst peforming this testing, it was decided that it should be tested against domestic, household methylated spirit (in case in home use someone got desperate and used their on hand alcohol for the sanitisation. I was of course being very careful measuring and weighing my solvents and reagents, and I am not a chemist, but I couldn't work out why some of the measurements I was taking did not correspond to my calculations, so I was thinking about the denaturing compound throwing me off.

Anyway, long story short, I eventually discovered my source of discrepancy, it turns out that household 'metho' is now actually 'etho' - reading the bottle (always the last resort as we know) your common, garden variety 'methylated spirit' is now denatured ethanol...