Isopropryl alcohol is toxic
and will blind you if you drink it. This propellant is a concentrated form of rubbing alcohol. Not recommended for internal use.
On a related note, some Soviet era aircraft like the Mig-25 used alcohol for things like cooling the avionics. Not just any alcohol but very pure ethanol. If you read "Mig Pilot", you'll see where he discussed the problem of the ground crews and other pilots drinking the coolant. Alcoholism was rampant in the Soviet Air Force, especially at the remote airfields. When he suggested switching to some other type of coolant, he was told to mind his own business.