What is the requirement for under-sink storage?

Any examples are for illustrative purposes only. 

The Joint Commission standards do not specifically prohibit all under-sink storage, but a risk assessment is to be performed to determine the organization's accepted practices, with a resulting policy established and disseminated to staff for implementation. The survey process will assess the policy for effectiveness and verify through tracer activity that the policy is being followed. 

The risk assessment shall establish if anything stored under a sink could be damaged by a sink plumbing leak or the moist environment, and under-sink storage of those items shall be prohibited by the resulting policy. CDC guidelines do not support the storage of medical or surgical supplies under a sink. Other examples include reagent and chemicals that could have an adverse reaction if exposed to water/sewer/moisture, cleaned patient care equipment, etc. Trash bins or cleaning supplies located under sinks would typically not be an issue. 

The organization should also determine if their local health department or state licensing/health organization has any prohibitions.