Final answer:
When hot TCS food on a self-service bar drops below the safe temperature of 135°F after 2 hours, the food worker should discard it immediately to prevent foodborne illnesses.
Step-by-step explanation:
When hot TCS (Time/Temperature Control for Safety) food is placed on a self-service bar, it should be kept at or above 135°F (57°C) to maintain its safe temperature and prevent bacterial growth. However, if the hot TCS food drops to 120°F (49°C) after 2 hours of service, this is considered a failure of temperature control.
In this case, the food worker should discard the hot TCS food immediately. Perishable foods left between 40°F (4°C) and 140°F (60°C) for more than 2 hours can become dangerous to eat due to rapid bacterial growth, increasing the risk of foodborne illnesses. It is important to follow proper temperature control measures to ensure food safety.