Which of the following is a chemical contaminant?

A chemical contaminant refers to harmful substances that can inadvertently enter food and cause health issues. In this case, copper utensils are considered a chemical contaminant because they can leach copper into food, especially when cooking acidic foods. This leaching can lead to copper toxicity in individuals consuming food prepared with these utensils.

On the other hand, vegetable oil, whole grains, and natural spices are generally safe and do not pose a chemical contamination risk when used properly in food preparation. Vegetable oil is a staple cooking ingredient, whole grains are a nutritious food source, and natural spices enhance flavor without introducing harmful chemicals. Thus, it is important to be cautious about the materials used in food preparation to prevent potential chemical contamination.