Salinas, CA-based Classic Salads doesn’t yet know what led to a recent sample of the company’s product testing positive for Salmonella contamination, but the company is, according to The Produce News, attempting to get to the bottom of the problem.

According to Classic Salads Sales Manager Lex Camany, the company was alerted through a third-party audit conducted by Primus Labs to a presumptive positive test result at 2 p.m. Pacific Standard Time on Thursday, July 27. An hour later, it began voluntary recall procedures for the entire day’s harvest in question: the July 24 harvest of baby spinach and spring mix from various locations in the Salinas Valley, which was distributed to foodservice accounts in the United States and Canada.

Mr. Camany was further cited as saying the recall involved up to 30,000 packages of baby spinach and spring mix products and cost the company up to $500,000. Though the recall already was in place, Classic Salads sent out samples to a separate, independent lab on Friday, July 28 — the same day much of the product was landing at foodservice sites around the nation.

On Saturday, July 29, Primus returned a "negative" finding for Salmonella contamination from its samples. Then on Monday, July 31, the separate, independent lab enlisted by Classic Salads returned a "positive" finding for Salmonella contamination from one sample.

As of Aug. 8, there had been no reports of illnesses related to consumption of the produce. All baby spinach and spring mix in question was harvested from several locations in the Salinas Valley.

Classic Salads is certified by the American Institute of Baking and by the USDA through USDA’s Qualified Through Verification program. On July 26, the day before being alerted to the presumptive positive testing result, Classic Salads attained a Level 1 score – the highest given by organization. Since the recall, Classic Salads has been working with two more labs to try to determine the cause of the contamination.