A recall was issued for Marketside Fresh Broccoli Florets, a brand of 12-ounce washed and ready to eat broccoli florets sold at Walmart, in Louisiana and 19 other states.

The washed and ready-to-eat broccoli was past its best-if-used date and was no longer on store shelves at the time of the recall, but the FDA said that consumers may still have it in their freezers.

The Food and Drug Administration has upgraded its classification of a broccoli recall initially reported in late December, labeling it as “Class I” — the agency’s most serious recall category.