Ask A Scientist Chemistry Archive

  
name         Jennifer J.
status       educator
age          20s

Question -   I teach 8th grade science, and many experiments in the
book call for the use of ethanol.  Can rubbing alcohol be used?  If not,
where can I get ethanol?
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Whether or not you can substitute isopropanol (rubbing alcohol) for ethanol
(denatured) depends upon the experiment. You can obtain isopropanol (70% or
91%) and denatured ethanol at any large pharmacy.
Since you are teaching 8th graders who are in their "experimentation" phase,
caution them about ingesting and/or "sniffing" either substance. Yes, that
will produce a "high", but both are toxic when inhaled.

Vince Calder
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Rubbing alcohol is not ethanol, and you should not substitute this in your
experiments---they may not work, and it could be dangerous.  If you know a
chemist who can look at your labs and say that it will work and is safe,
perhaps you can substitute, but don't assume you can.  You can order ethanol
from a science supply warehouse like Fisher. This lab ethanol usually has a
chemical additive to keep people from poisoning themselves by drinking it.

Pat Rowe
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Additional Entry - 1/22/2006
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The additives (denaturants) placed in ethanol can often make the chemical
more poisonous.  The additives, typically other solvents like methanol,
isopropanol, kerosene, gasoline, etc., convert the ethanol from a potable
(and therefore taxable as an intoxicating beverage) substance to one that is
not potable and therefore not taxable as a beverage.  There are also other
application-related reasons that the denaturants are added.  A state liquor
license would be needed to sell pure ethanol.  But denatured ethanol is sold
at most hardware stores.

Pure, 200 proof ethanol is poisonous if you drink too much of it.  But
denatured ethanol can be poisonous even in small doses.

Kristopher Sebring
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