The CDC recommends that dental unit water-lines at least meet the:

The correct answer is that the CDC recommends that dental unit water lines at least meet the EPA standard for drinking water. This recommendation is based on the importance of ensuring that the water used in dental procedures is safe and free from harmful microorganisms. The EPA's standards are designed to protect public health by setting limits on the levels of contaminants in drinking water, which makes them appropriate for dental unit water lines as well.

Maintaining water quality in dental instruments and units is essential, as it helps prevent the risk of transmitting infections to patients. Ensuring that the water used in these settings meets or exceeds the EPA standards helps safeguard both patient and staff health.

Other options, while relevant to various aspects of health and safety, do not specifically address the standards for dental unit water lines in the same way as the EPA's regulations do. For instance, FDA standards are typically more focused on device safety and effectiveness rather than water safety, and OSHA regulations pertain to workplace safety and health rather than specific water quality standards. WHO recommendations, while important for global health, may not be tailored to dental settings in the same manner as the EPA's guidelines. Thus, the emphasis on meeting EPA standards underscores the priority of patient safety in dental practices.