Sinks with one or two compartment are primarily used as prep sinks in which fruit and vegetable products are washed before serving. Single-bowl sinks can also be used as mop sinks, but you cannot use a single sink as both a mop and prep sink; the risk of food contamination is too high. Sinks with three and four bowls are used to wash large pots or pans that will not fit into the washer. Health codes also require that at least a three-bowl sink be present in every commercial kitchen, in case the dishwasher breaks down.