You may want to put down your fork for this.

The Food and Drug Administration is warning shoppers not to eat, sell, or serve the Great Value raw frozen shrimp sold at Walmart after Customs and Border Protection officials detected possible contamination from Cesium-137, a radioactive isotope.

“If you recently purchased one of the impacted lots of Great Value raw frozen shrimp from Walmart, throw it away,” wrote FDA officials in a statement on Tuesday.

The CBP initially flagged the presence of Cesium-137 after screening shipping containers at four domestic ports. The FDA said in a press release that radioactive testing on shrimp from the Indonesian distributor BMS Foods also came back positive.

So far, none of the shrimp tested as radioactive is believed to have reached grocery store shelves, but a few containers from BMS Foods did reach grocers after the CBP’s initial detection.

The FDA is now recommending a recall of all BMS Foods shipments. The agency has also temporarily blocked imports from the company after finding that it has violated the Federal Food, Drug, & Cosmetic Act by handling products under conditions that could expose them to radioactive contamination.

According to the Environmental Protection Agency, Cesium-137 is a byproduct of nuclear fission, which can cause burns, acute radiation sickness, and even death with significant exposure.

Food recalls due to radioactive contamination are relatively rare. After the 2011 Fukushima Daiichi nuclear disaster in Japan, the FDA restricted imports of certain seafood and produce from affected regions due to Cesium-137 exposure and did not fully lift the restrictions until 2021.

Walmart did not immediately respond to a request for comments.