I was at Walgreens tonight and happened to notice bottles of 91-percent isopropyl alcohol on the shelf, and I picked up two bottles and then noticed that one had an expiration date of Feb. 2012 and the other one was March 2013--same brand, same size. What's the typical shelf life of isopropyl alcohol? Is the shelf life shorter for 91-percent alcohol rather than 70-percent alcohol? I'd like to have an ample supply of alcohol for medical needs.
Also, would it be best to transfer isopropyl to glass jars (mason jars, probably) to extend their storage life? What kind of degradation will isopropyl go through if held way past its expiration date? How long will it still be effective as a disinfecting agent?