In the sterile processing area, what is the minimum number of air exchanges per hour recommended?

• A. Four
• B. Six
• C. Eight
• D. Twelve

Answer: (C)

Air changes per hour (ACH) measure how often the room’s air is replaced in an hour. In a sterile processing area, enough ventilation is needed to dilute and remove aerosols and dust generated during decontamination and instrument processing, helping to keep the environment and the sterile items clean. The minimum recommended is eight ACH because it provides sufficient dilution to reduce contaminant concentrations without being excessively energy-intensive. Fewer changes (four or six) would allow contaminants to linger, increasing risk to sterile items and staff. More changes (twelve) might be used in higher-risk areas, but eight is the established minimum for SPD as the baseline standard.