Which of the following is a way food handlers can cause a foodborne illness?

Failing to wash hands after restroom use is a significant way food handlers can cause a foodborne illness. When food handlers do not properly wash their hands after using the restroom, they can transfer harmful bacteria and viruses to food, surfaces, or utensils. This lack of hygiene can lead to contamination of food products, thereby increasing the risk of foodborne illnesses. Proper handwashing is crucial to eliminate pathogens that may be present on hands, especially after using the restroom—one of the most critical times for hygiene in food preparation environments.

The other options listed represent practices that promote food safety and hygiene, such as following handwashing techniques, using gloves, and wearing clean uniforms, which help minimize the risk of foodborne illnesses.