Mondelez Global says it’s voluntarily recalling some of its Ritz Cracker products over potential risk of salmonella.

The Hanover, New Jersey-based company says it’s recalling 16 varieties of Ritz Cracker Sandwiches and Ritz Bits products in the U.S. The products contain whey powder, which its supplier has recalled due to the potential presence of salmonella.

Mondelez says no illnesses have been reported yet. Symptoms of salmonella include fever, nausea, vomiting and diarrhea. It can cause serious and sometimes fatal infections in the young, elderly or those with weakened immune systems.