In a self-service area, cross-contamination can occur when there are bacteria in a kitchen that are transmitted to the food by direct contact. Typically in the culinary, a knife or cutting board is the most common kitchen devices that appear to be tainted by cross contamination. In reality, it's not only bacteria that are transported or relocated from one location to another, but may also be a virus or toxin of some kind or even a cleaning product, so whatever it is, it is considered a cause of cross-contamination if it eventually comes into contact with somebody's food.
