The sun's radiation causes cancer, yet placing a blanket warning stating the sun causes cancer likely leads many to wholesale avoid the sun, which would be folly (humans need some amount of sunlight).

Similarly, imagine if nutrition facts labels only had to state whether the food could be potentially unhealthy, without any other nuance.

A sensible version of Prop 65 would acknowledge the specific substance, its dosage, and the best known safe dosage. Equipped with that information a consumer can make an informed decision.

Since the sun is outside the jursdiction of California, it doesn't need a prop 65 warning.

I would love to see prop 65 stickers at the exits to Starbucks(1) warning that going outside exposes you to the sun, a known carcinogen.

1. Starbucks because they are a particular case where acrylamide is a normal byproduct of roasting, and there's basically (as I understand it) no way to have it not be part of the result.

And the flaw in that argument is that every product is made with many different chemicals, at least one of which almost always seems to be on the Prop-65 list.

Regardless of the strength of the evidence, which is yet another problem with the whole idea.