The U.S. Food and Drug Administration (FDA) has released the results for its testing of per- and polyfluoroalkyl substances (PFAS) in seafood samples collected at retail. FDA conducted the limited survey as a preliminary step to determine if a more targeted or larger seafood survey should be conducted.

FDA tested 81 samples of clams, cod, crab, pollock, salmon, shrimp, tuna, and tilapia, most of which were imported to the U.S. FDA individually evaluated the samples for detectable levels of PFAS that have toxicological reference values.

After testing samples of canned clams from China, FDA determined that the food poses a public health concern due to the detected levels of perfluorooctanoic acid (PFOA), which is a type of PFAS associated with several serious health outcomes, including developmental effects, changes to liver function, reduced immune response, and increases in certain types of cancer. FDA states that it is working to determine the extent of PFOA in imported canned clams, as well as PFAS in other clam products, and that the agency will be taking action to ensure the safety of the U.S. food supply. After learning of FDA’s test results regarding their products, the two distributors of the samples with the highest levels of PFOA are issuing voluntary recalls.

Additionally, FDA found that, apart from the canned clams, all other seafood samples that were tested did not exhibit harmful levels of PFAS contamination. Aside from PFOA, the canned clams also did not show harmful levels of the other types of PFAS that the agency evaluated.

FDA states that it is actively engaged with all of the canned clam distributors involved in the agency’s testing to better understand the potential sources of PFOA contamination, which could help the firms take action through responsible product sourcing. FDA will also continue to test imported clams and take action when necessary. The agency plans to conduct broader testing of canned and fresh clams, both imported and domestically harvested, to better understand PFAS levels to determine the best approach for protecting public health.

FDA initiated the seafood survey based on its prior Total Diet Study (TDS), which found relatively low levels of PFAS in some seafood samples. The percentage of seafood samples with detectable PFAS, the types of PFAS detected, and the levels detected in multiple samples are higher in the recent survey than was found in the overall TDS samples. FDA states that the increased level of PFAS found in the recent survey may be attributed to the agency’s testing protocol; because seafood may be at increased risk for PFAS contamination from the environment, FDA tested more samples of specific types of seafood, as well as tested for certain types of PFAS that have been identified as being more prevalent in seafood.

FDA explains that other studies on clams from China and Europe have reported a range of levels of PFOA, including elevated levels. The agency states that FDA will follow the evolving scientific knowledge about PFAS in foods to help inform its regulatory approach. Information on future data and additional actions will be made available to the public through constituent updates.