Expert: Henry Boyter - 3/27/2008

Question
My husband and I can't agree.  Can a glass that once held alcohol still have "alcohol residue" on it?  He claims all the alchohol would evaporate over time.  Could a child safely drink out of a bar glass that once held alcohol?

Answer
I would suggest you are probably both correct.  There are several points to make.

1. The ethanol, the active ingredient will evaporate over time.  So from an intoxication point of view your husband is correct.  The time it takes of course will depend on many factors and there is no simple answer to what that time would be.

2. Unless you are talking grain alcohol, all alcohol prodcuts have other ingreients which give them color and flavor including sugar and salt.  Some of these materials will NOT evaporate, but again would not be harmful, unless there was a very unusual allergy involved.  So you are also correct to a degree.

3. If you wash the glass, all of this material is removed from the glass.

4. If a child is involved, an adult's judgement of evaporation should not be trusted.  Wash the glass.