Final answer:
TCS food has been contaminated if it remains in the temperature danger zone for extended periods of time.
Step-by-step explanation:
TCS (Time/Temperature Control for Safety) food has been contaminated if it remains in the temperature danger zone for extended periods of time. The temperature danger zone for food is between 4 and 60 degrees Celsius (40 and 140 degrees Fahrenheit), as bacteria multiply most rapidly in this range. If perishable food remains within the temperature danger zone for more than two hours, it may become dangerous to eat due to rapid bacterial growth.