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.