Alcohol is a poor choice if you are trying to illustrate over labeling, because alcohol, especially heavy consumption of spirits, has some notoriety as a cause of oral cancer.
Dosage is important in factoring risk. Problem with prop 65 it doesn't factor in risk at all. Potassium-40 produces ionizing radiation and is present with all sources of potassium. That doesn't mean you shouldn't eat Bananas.
http://www.nhs.uk/Conditions/Cancer-of-the-mouth/Pages/Cause...