The panel stops at the ingredients. The container has a chemistry of its own, and nobody prints it on the label.
A Panel Score is what it says: a reading of the printed panel. No label prints its own can lining, so a packaging penalty would be a guess dressed up as a measurement, and it would land on hundreds of products at once. We would rather tell you what is known, say plainly what isn't, and leave the number alone.
So nothing on this page costs a product points. If a manufacturer ever starts publishing its lining spec, that belongs in the brand transparency grade — the axis that already measures how much a company is willing to tell you.
A steel can needs a lining, or the food reacts with the metal. For decades that lining was an epoxy made with bisphenol A. Heat, fat and acid all pull a little of it into the food, and wet pet food is cooked in the can.
There is pet-specific evidence, not just extrapolation from human studies. In 2017 researchers at the University of Missouri fed dogs canned food for two weeks and found serum BPA rose roughly threefold, alongside shifts in gut bacteria and metabolic markers. It was a small study over a short window, and it measured exposure rather than harm — but it measured it in dogs, eating normally.
In cats the thread is older and looser. Canned diets have been associated with hyperthyroidism in population studies since the 1990s. Can linings are one candidate. Flame retardants in household dust are another. It is not settled, and we are not going to pretend otherwise.
Many makers have moved to linings described as BPA-NI, for “non-intent”: BPA is not deliberately used. What replaced it is usually a polyester or acrylic resin, or another bisphenol — most often BPS or BPF.
BPS and BPF are close structural relatives of BPA, and the early work on them raises some of the same questions. Toxicologists have a name for this pattern: regrettable substitution, where a flagged compound is swapped for a less-studied cousin and the label gets to say the flagged one is gone. “BPA-free” tells you one molecule is absent. It does not tell you what took its place.
A retort pouch is usually a laminate of polyester, aluminium foil and polypropylene. There is no epoxy lining, so the BPA question does not arise in the same way. Trays and tubs are commonly polypropylene with a peel lid; cartons are paperboard with a plastic and sometimes foil layer.
The trade is at the other end. A steel can is recycled almost anywhere. A multilayer pouch is recycled almost nowhere, because separating the layers costs more than the material is worth. Neither format is simply better than the other, and a page that told you otherwise would be selling something.
Whatever the container is made of, migration into food goes up with heat, with fat and with acid. Everything above is about what the manufacturer chose. This is the one variable in your kitchen.
Less than we would like, and we would rather show you the gap than paper over it. No database we draw from publishes the container as a field, so we only record it when a product's own name or size says so.
| Wet food, container known | 44 of 132 |
| Wet food, container unknown | 88 |
| Whole catalogue, container known | 196 of 562 |
Where we do know, it is on the product page next to the form. Where we don't, the page says nothing rather than guessing, because guessing is exactly what would make this page worthless.