What is the minimum number of air changes per hour required in an occupied laboratory?

The minimum number of air changes per hour required in an occupied laboratory is set at 8 to ensure adequate ventilation. This standard is crucial for maintaining air quality, as laboratories often handle volatile substances and flammable materials that can produce harmful fumes. The increased air exchange rate helps to dilute and remove potentially hazardous contaminants from the air, thereby reducing the risk of exposure to toxic gases or vapors. Additionally, the 8 air changes per hour guideline is designed to maintain a safe environment for personnel working in the laboratory while also complying with regulations set by health and safety organizations.

While lower air change rates may be appropriate for less hazardous environments, laboratories require a higher level of ventilation to accommodate the unique risks associated with chemical usage and to support safe work practices.