When a common ingredient used in a bunch of ready-to-eat foods is recalled things snowball. One recall announcement turns quickly into multiple and leads to larger questions about overall systems.

Or as Don told Consumer Reports last week, ‘It’s the nature of our complex food system today. If a potentially contaminated bit of onion gets used in a burrito,’ he explains, ‘you have to recall the whole burrito.’

Since Oct. 16, there have been at least 13 recalls of ready-made foods, such as salads, sandwiches, wraps, pizza, and burritos, due to potential salmonella and listeriacontamination. All of these foods have been traced back to a single plant owned by McCain Foods, in Colton, Calif., which processes, cooks, and freezes vegetables for distribution to other food producers.

To date, almost 4 million pounds of food sold under many different brand names have been recalled, and the Food and Drug Administration says more recalled products may still be announced.

All of the products involved are now past their expiration dates, so they shouldn’t be on store shelves. In addition, according to a spokesperson from the USDA’s Food Safety and Inspection Service (FSIS): “FSIS routinely conducts recall effectiveness checks … to verify [that] recalling firms notify their customers of the recall and that steps are taken to make certain that the product is no longer available to consumers.” (In this case, “customers” refers to food companies that purchase vegetables from McCain.)

The FDA notes that some of the recalled products require cooking, which could potentially kill dangerous pathogens. However, many of the recalled items are considered “ready-to-eat” or RTE.

And that makes them risky, says James E. Rogers, Ph.D., director of food safety research and testing at Consumer Reports. Even if the product was intended for cooking at home, different food items need to be heated to different temperatures to guarantee bacteria will be killed. Consumers may not always know to heat the product thoroughly.

Additionally, Rogers notes that handling products that contain foodborne pathogens—even if heated thoroughly—could contaminate anything they come into contact with, like your hands. The safest bet is to throw them out.