King Arthur Flour, in association with ADM Milling Company, announced a voluntary national recall of specific lots of its Unbleached All-Purpose Flour in 5-pound and 25-pound bags because of the potential presence of E.coli.
The recall is an expansion of another that was announced in June.
No illnesses linked to the product have been confirmed yet, the company said.
"Consumers should discard any affected products," the Food and Drug Administration said in a tweet. Consumers may also submit a claim for a refund or replacement on King Arthur's website.
King Arthur said the 5-pound bags were sold through retailers and distributors nationwide, and through its website, catalog and company store in Vermont. The 25-pound bags were sold only through Costco stores.
The CDC warns consumers to not consume raw products made with flour. This strain of E. coli, known as E. coli 026, is killed by heat through baking, frying, sautéing, or boiling products made with flour.
People usually get sick within three to four days after being exposed to this type of E. coli, the CDC says. Symptoms include diarrhea and cramps, and patients typically recover within a week.
Last month, General Mills announced a voluntary recall of its Gold Medal Unbleached All Purpose Flour for possible E. coli O26 contamination.
The CDC warned consumers in May about several flours that could be contaminated with E. coli O26. The recall included flours from King Arthur, Pillsbury and ALDI's Baker's Corner. At least 21 people from nine states were infected between December 2018 and May, though the outbreak was called off in July.