By Richard Parker, MBA, CHFM, CLSS-HC, FASHE, FACHE
More than a decade ago, CMS allowed for a revision of the previous acceptable range for relative humidity (RH) in operating rooms (30-60%) by dropping the lower limit to 20% through the use of a categorical waiver.
On its surface, the lower threshold improved flexibility by requiring less humidification in arid regions and even in areas challenged by variable seasons. However, use of the categorical waiver requires that the organization:
- Document its adoption of the CMS categorical waiver in writing.
- Document a gap analysis for supplies and equipment used in the operating room when the manufacturer’s instructions for use (ISU) require a minimum 30% RH.
- Document the temperature and humidity on procedural days per organization policy.
The gap analysis is a significant task. Some organizations quickly identify equipment or supplies that rule out the waiver’s adoption. Low humidity reduces the shelf life of specific supplies (e.g., biological indicators, chemical indicators used for sterilization monitoring, electrocardiogram electrodes) and increases the risk of electrostatic discharge could damage or disrupt electromedical equipment and potentially ignite a fire. Often, manufacturer’s instructions for use mandate the 30-60% range, especially in cases of older equipment.
Many organizations abandon the exercise once they realize the challenges associated with the gap analysis and settle for a range of 30-60%. As manufacturers gradually test the new humidity range and organizations replace equipment, the feasibility of making the change will improve.
Meeting the Range
Organizations that opt to remain in the 30-60% RH range are expected to maintain that range. Temperature is inversely related to relative humidity so a lower (and perhaps more comfortable temperature) equals higher RH. Survey citations related to air pressure, temperature, and humidity are frequent and nearly 25% of those findings are in high-risk areas like ORs.
Ongoing documentation of temperature and humidity on procedural days is essential to compliance. A response plan for when these measure fall out of range will factor in:
- The amount of deviation.
- The duration of deviation.
- The time of day that deviation occurs, i.e., occupied vs. unoccupied hours.
Taken together, these data points contribute to a risk assessment that should inform your response plan. This plan should be developed using a multidisciplinary team approach, including representatives from perioperative services, infection control, engineering, sterile processing and risk management. Identifying the impact on patient safety, services and supplies when temperatures or humidity levels fall out of the acceptable range in surgical suites will significantly aid in developing an effective response.
Deemed organizations must adhere to the Centers for Medicare and Medicaid Services (CMS) ventilation requirements, which specify criteria for new or renovated facilities. These requirements are outlined in the 2012 edition of NFPA 99, which references table 7.1 of the 2008 edition of ASHRAE 170. This document allows temperature ranges to be exceeded under certain conditions. To use this exception, the organization must do so in accordance with an established policy that defines limited cases based on the surgeon, patient or procedure. It is not acceptable to consistently maintain temperatures outside the required ranges.
Once the surgical procedure performed under exception is completed, the temperature must return to within the normal range. Additionally, relative humidity levels are expected to remain below 60% even when the temperature is temporarily adjusted outside the established range. High humidity elevates the likelihood of surface mold and mildew growth, may heighten the risk of infection, and is a less comfortable environment for operating room staff.
– Richard L. Parker is associate director, physical environment and life safety at Accreditation Commission for Health Care Inc. where he provides guidance to customers and surveyors in the ASC and hospital programs. Prior to joining ACHC full-time, Richard was an accreditation surveyor and Executive Director of Facilities for a 615-bed hospital system in Arizona.
