HEPA filters remove waste gases from the air.

• A. True
• B. False
• C. Not sure
• D. Not applicable

Answer: (B)

HEPA filters are designed to remove particulates from the air, not gases. They capture solid particles and many microbes as air passes through the filter via mechanisms like diffusion, interception, and impaction. Gases and vapors, such as ammonia, CO2, or volatile organic compounds, pass through the filter because their molecules are too small and are not adsorbed by the filter fibers.

To remove waste gases, you need adsorption or chemical absorption media, such as activated carbon, or other gas scrubbers in the ventilation system. In a lab setting, HEPA filtration helps keep the air free of particulates and microbes, but gas removal requires additional filtration stages designed for gases.