A cooking device comprising a system for reducing or eliminating cross-contamination between food to be cooked in the cooking device and food cooking in the cooking device, the cooking device including a cooking chamber, a door for accessing and closing the cooking chamber, a plurality of mechanisms (5, 6, 6', 6", 6′′′) for receiving and holding a plurality of food product carriers/trays at a plurality of predetermined carrier/tray levels for cooking food, the system comprising: a controller having a memory; and a user interface including a display and user input device, characterized in that the system receives an identification of the food to be cooked, obtains an hygienic safe control time parameter, referred to as HSCT, for the food to be cooked, wherein the HSCT is a time assigned to a food product to be cooked that indicates the minimum remaining cooking time for a food product cooking on levels below the selected level of the food product to be cooked, obtains a remaining cooking time and a carrier/tray level for each food cooking in the cooking device; compares the hygienic safe control time parameter (HSCT) to each remaining cooking time; and identifies safe carrier/tray level(s) for accepting placement of the food to be cooked, wherein the system obtains an HSCT for the food to be cooked and obtains the remaining cooking time and the carrier/tray level for each food cooking in the cooking device from the memory where HSCTs for foods to be cooked and cooking times and carrier/tray levels for food cooking in the cooking device are stored, wherein the controller or an associated control compares the HSCT to each remaining cooking time; and identifies safe carrier/tray level(s) for accepting placement of the food to be cooked, wherein the system provides the indication of safe carrier/tray level(s) for accepting placement of the food to be cooked on the display. a controller having a memory; and a user interface including a display and user input device, characterized in that the system receives an identification of the food to be cooked, obtains an hygienic safe control time parameter, referred to as HSCT, for the food to be cooked, wherein the HSCT is a time assigned to a food product to be cooked that indicates the minimum remaining cooking time for a food product cooking on levels below the selected level of the food product to be cooked, obtains a remaining cooking time and a carrier/tray level for each food cooking in the cooking device; compares the hygienic safe control time parameter (HSCT) to each remaining cooking time; and identifies safe carrier/tray level(s) for accepting placement of the food to be cooked, receives an identification of the food to be cooked, obtains an hygienic safe control time parameter, referred to as HSCT, for the food to be cooked, wherein the HSCT is a time assigned to a food product to be cooked that indicates the minimum remaining cooking time for a food product cooking on levels below the selected level of the food product to be cooked, obtains a remaining cooking time and a carrier/tray level for each food cooking in the cooking device; compares the hygienic safe control time parameter (HSCT) to each remaining cooking time; and identifies safe carrier/tray level(s) for accepting placement of the food to be cooked, wherein the system obtains an HSCT for the food to be cooked and obtains the remaining cooking time and the carrier/tray level for each food cooking in the cooking device from the memory where HSCTs for foods to be cooked and cooking times and carrier/tray levels for food cooking in the cooking device are stored, wherein the controller or an associated control compares the HSCT to each remaining cooking time; and identifies safe carrier/tray level(s) for accepting placement of the food to be cooked, wherein the system provides the indication of safe carrier/tray level(s) for accepting placement of the food to be cooked on the display.