Salinas-area Classic Salads has voluntarily recalled up to 30,000 packages of baby spinach and spring mix products in the past week after lab tests showed they might be contaminated with salmonella.

No illnesses related to consumption of the produce — grown in the Salinas Valley and sold almost entirely to food service customers like restaurants and hotels — have been reported.

Company officials recalled the product, distributed nationwide and in Canada, hours after the sampling of a finished product on July 27 tested positive for salmonella, said Classic Salads sales manager Lex Camany.

The decision will cost the processor-shipper more than $500,000. Officials could have waited until Monday to get confirmation that the test was accurate and then recall the produce, but they decided not to take any chances, said Camany.

The big question that remains unanswered is where the salmonella bacteria came from. Camany said the company is in contact with research scientists and consultants and is "expeditiously researching how this could have happened."