Grease traps are based on the principle that FOGs float in water and solid particles sink. The trap’s baffles slow down the inflow of wastewater. This allows the unit to settle and separate oils, water, and food particles. FOGs are prevented from flowing through the outlet by a trap and retained in the unit, along with food particles. This allows for cleaner water to flow through. Regular servicing is required to remove the waste and keep it from building up.