Trader Joe’s issued a recall on Wednesday after a potential threat of salmonella was detected in certain lots of in-shell, roasted pistachios.

The company, which operates a store on Marginal Way in Portland, said it was notified by its supplier that packages stamped with the “Best if used by” date codes from 2016 Oct. 27 through 2016 Nov. 04, could be contaminated.

The products are sold in 16-ounce plastic bags with the code information stamped on the back and along the bottom. The products have been distributed to Trader Joe’s stores nationwide. They include dry roasted and unsalted pistachios, dry roasted and salted pistachios, and roasted and salted pistachios.

Customers who purchased the pistachios are urged not to eat them. They can be returned to the store for a full refund.

No illnesses have been reported to date. Salmonella can make people sick, often causing diarrhea, fever and abdominal cramps 12 to 72 hours after infection. Most individuals recover without treatment, according to the Centers for Disease Control and Prevention.