Just to fill the pot with more speculation, my recollection of college chemistry tells me that alcohol readily absorbs moisture from the atmosphere, so that any container opened to normal atmospheric conditions for more than a few seconds will autodilute to somewhere around 93% (that's the number in my mind for ethanol). No doubt, the percent purity will differ for different forms of alcohol. This makes requiring a 100% purity unattainable.
I checked my 1982-1983 ed. of the CRC Press Handbook of Chemistry and Physics and found no useful information for this topic. I used to have a bottle of isopropanol in the lab. If I remember to, I'll see if it's labeled any particular way. Peter L. Tarver Nortel [email protected] > -----Original Message----- > From: Chris Dupres [SMTP:[email protected]] > Sent: Thursday, July 09, 1998 9:57 PM > > Hi Ned. > > You wrote: > <I need some help to solve a difference of opinion. A number of > standards require isopropyl alcohol for durability of marking test. > e.g. IEC 1010-1, Clause 5.3 and IEC 601-1, Clause 6.1.z. > > The difference in opinion is in the concentration. The standards just > state "isopropyl alcohol". Some say 70% others say 100%. What are > other people using? > > > I use a material labelled 'Isopropyl Alcohol' for the rub test. That's > what it says on the tin, and I can only assume that it is 100%. I am sure > that it is 100% because spills evaporate very quickly and leave no water > behind, I'm sure that if it was diluted the water would remain long after > the IPA had gone. > > Does that make sense?. > > Chris Dupres > Surrey, UK.
