Potential Adverse Impact of Lower Relative Humidity (RH) in Operating Rooms (ORs)
15-27-Hospital, CAH & ASC
• Information on OR RH is provided for Ambulatory Surgical Centers (ASCs) & Supplemental Information for Hospitals & Critical
Access Hospitals (CAHs) Using the Categorical Waiver of Life Safety Code (LSC) Anesthetizing Location RH Requirements
• The Association for the Advancement of Medical Instrumentation (AAMI) coordinated the release on January 5, 2015 of a Joint
Communication of multiple healthcare-related organizations on how a RH of <30% in ORs may affect the performance of some sterile
supplies and electro-medical equipment.
• S&C 13-25-LSC & ASC permits hospitals and CAHs to use a LSC categorical waiver to establish an RH level <35% in anesthetizing
locations. Before electing or continuing to use this categorical waiver, hospitals and CAHs are expected to ensure that the
humidity levels in their ORs are compatible with the manufacturers’ instructions for use (IFUs) for the supplies and equipment
used in that setting.
• ASCs do not require a categorical waiver in order to use a lower RH level in their ORs but also need to ensure they comply
with the IFUs for their OR supplies and equipment.