Does frozen seafood packaging add extra microplastics to your fish?

What's actually in it

Frozen seafood comes with a double dose of plastic exposure. First, fish and shellfish pick up microplastics in the ocean while they're alive. They eat them, breathe them through their gills, and absorb them through their skin. Second, the plastic packaging used to freeze, store, and sell the seafood adds even more particles.

Frozen shrimp, fish fillets, squid, and mussels are typically sold in plastic bags, trays, or shrink wrap. The freezing and thawing process can cause extra shedding from these materials.

What the research says

A 2026 study in Environ Pollut tested packaged frozen seafood for microplastic contamination. The researchers analyzed multiple types of seafood bought from regular grocery stores.

Every sample contained microplastics. The particles included polyethylene, polypropylene, and nylon. Some of these match ocean pollution, but others match the packaging materials, which means the packaging itself was adding to the problem.

The study calculated health risk scores based on how much seafood a typical person eats per week. For heavy seafood eaters, the estimated microplastic intake from frozen products alone was enough to raise concern.

Buying fresh seafood from a counter and bringing your own container avoids the packaging layer. If you do buy frozen, transferring it to a glass container before thawing prevents the plastic from shedding more particles as it warms up.