Which of these actions is a violation of salon practice regulations?

Sharing tools among clients without disinfecting is a clear violation of salon practice regulations because it poses a significant risk of cross-contamination and the transmission of infectious diseases. Proper sanitation and hygiene practices are essential in any beauty or personal care setting to ensure the safety of clients and to maintain a professional standard of care.

Regulatory guidelines typically require that any tools or implements that come into contact with a client's skin or bodily fluids must be either single-use or properly disinfected before being used on another client. This is to prevent the possible spreading of bacteria, viruses, or other pathogens that could lead to infections.

In contrast, practicing on mannequins, maintaining a clean environment, and keeping licenses displayed are all actions that align with best practices in the industry. These actions promote professionalism, safety, and compliance with regulatory standards, contributing positively to the overall salon experience.