Environmental Engineering Controls in Operating Rooms: A Qualitative Study of HVAC and Cleanroom Systems in Preventing Healthcare-Associated Infections

Introduction: Hospital-acquired infections (HAIs) remain a major challenge in healthcare facilities, particularly in high-risk areas such as operating rooms. Environmental engineering controls, including Heating, Ventilation, and Air Conditioning (HVAC) systems and cleanroom design, play a critical role in infection prevention and control (IPC). However, empirical insights from occupational health and safety (OHS) experts regarding technical implementation remain limited. Methods: This qualitative study employed a semi-structured, in-depth interview with a certified hospital environmental engineering and occupational health expert. Data were analyzed using thematic analysis to identify key environmental parameters and infection prevention mechanisms within hospital operating rooms. Results: The findings indicate that effective infection control depends on the integration of multiple environmental control parameters, including temperature regulation (18–23°C), relative humidity (≤60%), positive pressure differentials, fresh air supply (20–30%), air change rates (15–25 ACH), and laminar airflow distribution. The implementation of ISO-6/Cleanroom 1000 standards above the operating table, supported by HEPA filtration and hygienic Air Handling Units (AHU), was identified as essential to maintaining sterile and hygienic air conditions. Automated Environmental Monitoring Systems (EMS) and continuous 24-hour operational stability further ensure regulatory compliance and minimize microbial growth risks. Conclusion: HVAC and cleanroom systems constitute critical environmental control infrastructures rather than merely comfort-support systems in hospitals. Their proper design, monitoring, and continuous operation are fundamental to strengthening infection prevention strategies, reducing HAIs, and enhancing surgical patient safety outcomes.