Jaime, the morning prep cook at a local restaurant, was preparing shredded cheese to be used on pizza. His procedure included cutting the cheese into small blocks and then shredding the cheese by hand. He prepared several 4-gallon containers and left the containers out at room temperature (70°F, 21°C) until use. Three of the four containers were used on pizzas later that day. The next day, the fourth container of cheese was used. On both days, the pizzas were cooked in an oven set to 500°F (260°C). Four days later, several people came back to the restaurant and said that they had become ill a few hours after eating pizza there. Only people who ate pizza on the second day appeared to become ill.  1. What foodborne hazard may have been associated with this foodborne illness?
2. How could this have been prevented?