The Joint Commission recommends maintaining operating room relative humidity at what range?

• A. 50-55%
• B. 30-40%
• C. 60-70%
• D. 40-50%

Answer: (A)

Maintaining the operating room environment with a moderate humidity level supports infection control, equipment safety, and staff comfort. A mid-range humidity—around half of saturation—creates a balance: it reduces static electricity that can affect sensitive equipment and spark near electrical devices, while avoiding excess moisture that could cause condensation, promote microbial growth, or compromise sterile packaging. This level also helps prevent dryness that can irritate staff and damage materials. The Joint Commission supports monitoring and sustaining environmental conditions in the OR within a controlled, middle-range humidity to prevent fluctuations that could impact patient safety. So the recommended target is a mid-range humidity, roughly around fifty percent, give or take a bit.