Which of the following practices is essential for preventing foodborne illness?

Ensuring proper handwashing by staff is crucial for preventing foodborne illness because it helps eliminate pathogens that can be transferred to food during preparation and service. Food handlers are often in contact with raw ingredients, surfaces, and equipment that may harbor harmful microorganisms. Effective hand hygiene, including washing hands with soap and water at critical times—such as before handling food, after using the restroom, and after touching any potentially contaminated surfaces—significantly reduces the risk of contamination.

Other practices might not directly prevent the transmission of pathogens as effectively. For instance, allowing food to cool at room temperature can promote the growth of bacteria if food is not cooled promptly within safe temperature limits. Buffet-style serving methods can also pose a risk if proper hygiene measures are not enforced, as multiple people could inadvertently introduce pathogens. Serving only pre-packaged foods may reduce some risks, but it does not address the potential for contamination during preparation, serving, or handling of those packages. Thus, while all food safety practices have importance, handwashing is a fundamental step that directly impacts foodborne illness prevention.