"For example, in 2010, General Mills announced it had found a "BPA-free alternative" can liner that works with tomatoes. It said it would begin using the BPA-free alternative in tomato products sold by its organic foods subsidiary Muir Glen with that year's tomato harvest. As of 2014, General Mills has refused to state which alternative chemical it uses, and whether it uses it on any of its other canned products."
It boggles the mind that a company is allowed to keep secret which chemicals it uses in food/food packaging.
Snark aside, it's simply a problem of money in politics. It costs corporations less to lobby against regulations than it does to follow said regulations.
"This tactic—which researchers call “regrettable substitution”—has been used in the formulation of products such as pesticides, flame-retardant furniture, non-stick pans, and nail polish. The chemical replacements need only be different enough to be considered distinct by regulators. They don't have to be proven safer."
It makes me wonder if regulators should have substitutes in mind before making public policy descriptions. Or if they should continue to rely on markets to "find a way".