Just thinking ahead here for some possible pitfalls why companies would be against it.

Unfortunately I just see anything that they don’t want to disclose (because it’s harmful) to become a trade secret

Then mandate a label that clearly states there are unknow ingredients that the manufacturer refuses to list.

On any ingredients list, that should be assumed when there is a vague ingredient like "Artificial Flavors".

Industry plainly lists potassium sorbate, sorbic acid, and sodium nitrite, which are known carcinogens.

On top of that, the packaging matters: PET is a phtalate which is an endocrine disruptor.

They are going to be against it anyway.

In principal, known toxins (when at anything even close to toxic doses when used normally) should be just not allowed in consumer products in the first place.

In practice, people like their alcoholic drinks and don't understand why that by itself is enough to require the Californian proposition 65 "substances at this location are known to cause cancer" sticker.

The good news is that the FDA sets "acceptable levels"[1] in food, for things like animal feces, insect infestation, mold, rodent hairs and filth, maggots, and so on, beyond which enforcement is mandatory. The bad news is they are nonzero.

1: https://www.cnn.com/2019/10/04/health/insect-rodent-filth-in...

>The bad news is they are nonzero.

Especially with mold, zero is very very difficult to attain.