Prop 65 gets a lot of shit, but the way it is implemented makes a reasonable amount of sense. If there is evidence that the substance causes harm, it gets listed and companies producing products that contain it have to either notify consumers that it is in there, or they have to demonstrate that the amount of the substance does not cause harm (there's a very low general threshold and some specific thresholds that are higher).
That leads lots of companies to go the low cost route and use the notification safe harbor, but it also creates an incentive to find alternatives and so on. You get cases like you mention, but the alternative to the evidence based approach is to hand wave that it's not harmful.
Prop 65 appears to have become a victim of its own incentive structure. When it first landed, companies had to balance whether the potential loss of sales from applying a label was worth lowering enforcement risk, so there was reason to think: is the thing I’m selling actually potentially harmful under this regulation’s definition?
But once the momentum of having these labels on _a lot_ of products gets established, customers start to un-see them, and the sales risk of applying the label drops to negligible. So just slap it on everything, which adds more noise to the signal, which further derisks adding the label, etc.
At this point it probably just needs a hard reset; tear out prop 65 in the process of replacing it with something that learns from these lessons. Maybe make the warning label cost something e.g. mandate that its application include quantitative risk backed by a third party lab test.
No, it doesn't "make a reasonable amount of sense." When everything causes cancer, nothing does. No useful information is being communicated to the consumer.
Meanwhile, the credibility of the scientific establishment in Joe Sixpack's eyes takes another hit, with all-too-predictable consequences.
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.
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.
That leads lots of companies to go the low cost route and use the notification safe harbor, but it also creates an incentive to find alternatives and so on. You get cases like you mention, but the alternative to the evidence based approach is to hand wave that it's not harmful.