According to ventilation standards in an operating room (OR), how many air exchanges are recommended per hour?

• A. 10 air exchanges
• B. 15 air exchanges
• C. 20 air exchanges
• D. 25 air exchanges

Answer: (B)

Fifteen air exchanges per hour is the standard rate used in operating rooms to keep the environment clean and safe. This measure shows how many times the entire room air is replaced each hour, which helps dilute and remove contaminants such as surgical smoke, dust, and microbial load from the sterile field. Setting a minimum of fifteen exchanges balances effective ventilation with practical concerns like energy use and temperature control. While some facilities may operate at higher rates for specific procedures or design reasons, fifteen is the commonly recommended minimum to support infection control and air quality in the OR.