Expert: Kevin - 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
Hi Sue.
The answer is quite complex. Alcohol is volatile and so escapes into the air all the time from glasses, bars, wineries, distilleries and there are also numerous natural fermentation processes that occur (including rotting vegetation and fruit) putting alcohol into the air. Sunlight slowly destroys this alcohol as UV light is zapping the molecules to carbon dioxide and water. The rate of destruction and rate of generation means that there is always a tiny bit of alcohol in the air.This means that we are all exposed to tiny amounts of alcohol at all times. It is not toxic to us or our children because as a very wise man Paracelsus, the father of toxicology, once wrote: "Everything is poison, there is poison in everything. Only the dose makes a thing not a poison".

In other words, you can eat cyanide, but not very much!

Also there are tiny amounts of alcohol in our food due to natural processes but not at a level that can cause harm, as the human body rapidly converts alcohol to harmless energy or food.

So given that there are tiny and harmless amounts of alcohol in the very air we breath and the food we eat we have to say would there be more or less in a bar glass that once held alcohol.
The bar glass with a neat whisky (preferably Lapgroaig) in it has the following life cycle.

1. With two fingers of Laphroaig :-)
2. Empty :-(
3. Wet with alcohol
4. Dried out naturally.
5. Washed
6. Dried

So condition 1 would be dangerous to a child.

Condition 2 and 3 would not be dangerous but may affect the child's behavior over the short term.

Condition 4 is the most dangerous, not because of the alcohol, but it is very unhygienic (germs).

5 is OK and 6 is perfect.

You are probably both correct.


I hope this helps
Best wishes
Kevin