Nearly every restaurant chain now gives its employees guidelines for food safety. These guidelines cover everything from proper hand washing to the proper order for cleaning surfaces in the restaurant. They also cover cooking times and temperatures, which would have lessened the severity of the 1993 Jack in the Box outbreak. Some chains employ people whose only jobs are to clean and inspect their restaurants, or the chains purchase inspection services from other companies. Mass-production is central to fast food. It allows restaurants to receive and store a large amount of food, then cook and serve it as needed on orders.