Posted by chemstudent on .
Why is rubbing alcohol poisonous?
Some rubbing alcohols are made from isopropyl alcohol which you clearly can't drink, but most rubbing alcohol is made from ethanol and water which are the same ingredients in alcoholic beverages.
I hear that rubbing alcohol uses "denatured" alcohol. Is this because there are other poisonous additives present such as acetone, or is this because the actual ethanol molecules are different from those in alcoholic beverages in some way?
Most rubbing alcohol I have seen ins stores is isopropyl, which is poisonous. So is methyl alcohol. Denatured (ethanol) alcohol contains additives to make it poisonous or at least unpalatable. Additives vary from this list:
methanol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, denatonium, and kerosene. It is still mostly ethanol, and those molecules are unchanged.
Here us a site that may clear up some of the confusion but it adds confusion in some respects also.
I, like DrWLS, see rubbing alcohol as isopropyl alcohol. This article surprised me that ethanol was EVER used as rubbing alcohol. I am unsure of it but some confusion may arise from different standards used in the UK and the US.The denaturing is added to ethanol to keep people from drinking it. Any ethanol used to make the rubbing alcohol variety can be sold to the public very much cheaper than the ethanol at the liquor store BECAUSE ethanol at the liquor store is taxed so highly. The ethanol used in the rubbing alcohol variety has the denaturing agent agent added so people won't buy that to drink which leaves the government out the tax. By adding the toxic agent as the denaturing agent people will use the rubbing alcohol for rubbing and the liquor at the liquor store for drinking. That is most people will. I hear of people dying because they drink the denatured stuff. Just to give you an idea of the tax---back when I was working, I was in charge of the ethanol and its disposition at the university. We could purchase the ethanol without paying the tax. It has been a few years now and I know prices have increased due to inflation but I could buy 190 proof alcohol (95% ethanol/5% water) then for about $1.00 U.S. per gallon. I could purchase 200 proof alcohol (100% ethanol) for approximately $1.00 per pint. We kept it in a safe (with a combination lock) and federal inspectors came by (unannounced) periodically. I bought the 190 proof stuff in 55 gallon barrels and the 200 proof stuff in cases of 24 pints to the case. I know little of this is what you asked about but I think it is related to the question.