RE: Chemical Question
Thought a few added points would also help. Because ethanol is a preagent (starting chemical) for many processes, there are hundreds of methods for denaturing it (making it undrinkable) which will npot interfere with the reaction of a specific process. Typical additives are methanol, isopropanol (isopropyl alcohol), methyl ethyl ketone, methyl isobutyl ketone, denatonium, and even aviation gasoline!
So Isopropyl alcohol is not the same as denatured alcohol but is in some ways a denaturing agent.