I've tried calling manufacturers to determine if the food comes into contact with any parts that warranted the prop 65 warning, but they aren't any help.
Prop 65 is a warning about a long long list of chemicals which could or are present in even low to very low concentrations. You can read up on it and see the list online if you want. If I were making something involving food, I would put a prop 65 warning on it on general principles.
If the question gives you a headache or heart disease, better not take aspirin. It's on the list.... :-)