In 2010, the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) changed its standard for relative humidity in the operating room. The previous recommendation was for a range of 30 to 60 percent; the revision drops the lower range to 20 percent. This position paper issued jointly by the American Hospital Association, the Health Industry Distributors Association, and the Association of periOperative Registered Nurses, among others, raises concerns about this change because of the sensitivity of certain electro-medical equipment to dry air conditions. A series of questions that a hospital or ambulatory surgery center might use to analyze the issues related to dropping to 20 percent humidity are included.
Source: Relative humidity levels in the operating room: Joint communication to healthcare delivery organizations. (2015, Jan.). Retrieved from http://aorn.org/-/media/aorn/guidelines/position-statements/posstat-endorsed-relative-humidity-joint-communicaiton.pdf