Concern over human and environmental health impacts of longer-chain PFAS (like PFOS and PFOA) has resulted in companies phasing out these compounds, but companies are simply replacing them with shorter-chain PFAS. The health impacts of shorter-chain PFAS are less studied than other PFAS and significant data gaps remain. Yet, in absence of clear evidence that these shorter-chain PFAS have negative health impacts, the FDA is approving them for use in products that come in contact with food.

You can read more about the details in a recent blog post by the Environmental Defense fund that does not shy away from describing the chemistry of different PFAS compounds.