A Northern California produce supplier said Sunday it is voluntarily recalling romaine lettuce that was shipped to 19 states, Puerto Rico and Canada over fears about possible E. coli contamination.

Salinas-based Tanimura & Antle said the recall is limited to a single lot of its Field Fresh Wrapped Single Head Romaine that was available at retail stores starting Aug. 2. The lettuce is packed in a plastic bag with the UPC number 0-27918-20314-9, and it may have a “best by” date of Aug. 19.

The company said some 2,095 cases were potentially affected. Of those, 1,969 cases were shipped to Puerto Rico and the following states: Alabama, Arkansas, Arizona, California, Georgia, Kansas, Kentucky, Maryland, North Carolina, New Mexico, Nevada, New York, New Jersey, Pennsylvania, South Carolina, Tennessee, Texas, Virginia and Washington.

The product was packed with either 12 or 18 heads per case.

The recall was being conducted in consultation with Food and Drug Administration, and was based on the testing of a random sample by the Canadian Food Inspection Agency. There have been no reported illnesses associated with consumption of this product.