Which of these does NOT cause chemical contamination of food?

Chemical contamination of food occurs when harmful substances, including compounds from certain materials, come into contact with food items. The correct choice indicates a scenario that does not lead to such contamination.

Using the correct concentration of quaternary ammonium to sanitize dishes is essential for ensuring food safety. Quaternary ammonium compounds (quats) are commonly used as sanitizers in food service establishments because they effectively reduce harmful microorganisms without leaving harmful residues when used correctly. In contrast, other options involve materials known to react with food or release harmful chemicals. For instance, stirring tomato sauce in a copper pot can lead to copper leaching into the food, while serving orange juice in a brass cup can cause the juice to react with the metals, leading to potential chemical contamination. Pouring lemon juice into a pewter cup can present risks as well, as pewter may contain lead or other harmful metals that can leach into acidic foods.

By recognizing that the use of quaternary ammonium at the correct concentration does not introduce harmful chemicals into food, it becomes clear why this answer is the correct one.