The problem with the Prop 65 warnings is it's rare for anyone who labels their product with the Prop 65 warning to actually list the chemical that triggers the Prop 65 warning. It's not possible for a consumer who sees the label to make an informed decision not knowing what the chemical in question actually is. Some things are painfully obvious and expected, such as at a gas station. But PG&E or CalTrans sends these notices out for moronic things like sand. So the sand they use on roads is inherently more dangerous than the same sand in the sand box?

To make matters worse, the responsibility to label anything with Prop 65 falls to the manufacturer or owner (eg a location) and not determined as such by any government agent. This means that some products (locations as well) are labeled as such by the manufacture (or owner) just to cover their own butts. There's no consequence for posting the notice even if there is no known cause to do so. IMHO, this waters down the meaning of the posting especially with the point above.
This also has the opposite effect that some manufactures
don't label their products appropriately. Either they're not aware of what their products contain (toys are a good example). Or they simply don't give a rats ass about your safety.
Go check out the list and see what's actually listed there. It's
---smurfing--- insane. Since anything in excess causes death, everything except
water will probably make the list eventually.