Worse, you might not even know it’s there, because labelling of this potentially toxic chemical is not mandatory in the US, says Ms Logan.
So what is it? It’s an additive—called sodium tripolyphosphate, or STPP for short—and it is used to make your seafood appear firmer, smoother and glossier. Seafood manufacturers may soak your seafood in a quick chemical bath of STPP in order to achieve these effects.
Some of the more commonly “soaked” seafood items include scallops, shrimp and anything filleted that’s very flaky—like hake, sole or imitation crab meat, Ms Logan continues.
If seafood is soaked for too long in an STPP bath, it may absorb more water, which means you’ll pay more for the product by the pound because the excess water makes it weigh more. A product may have been “soaked” with STPP if a milky white liquid oozes from the fish as you cook it, and it may also deflate in size a bit.
In large quantities, STPP is a suspected neurotoxin, as well as a registered pesticide and known air contaminant in the state of California.
How can one steer clear of STPP? Ask at your market or fish shop if the scallops or shrimp you’re being sold are “dry.” You can ask the same thing of waiters at seafood restaurants—they should have an understanding of the topic. (In industry-speak, “wet” fish means a product has been soaked in phosphates.) You can also check labels of packaged products, which may list STPP as an ingredient. Unfortunately, it’s not mandatory for companies and sellers to do so, concludes Ms Logan.