Final answer:
A dental assistant wiping a handpiece instead of sterilizing it violates OSHA guidelines, which require proper sterilization between patients to prevent cross-contamination.
Step-by-step explanation:
If you observe a dental assistant wiping a handpiece instead of sterilizing it, the code being violated is OSHA (Occupational Safety and Health Administration). Wiping is not an acceptable method of sterilization for dental instruments as it does not eliminate all microbial life, which is essential to prevent cross-contamination and to ensure patient safety. Sterilization procedures are a critical aspect of infection control in dental care, and all dental health practitioners are obliged to follow the guidelines established by organizations such as the Centers for Disease Control and Prevention (CDC) and OSHA which require the use of autoclaves or other sterilization devices on handpieces and other dental instruments between patients.