A key feature of a high-efficiency particulate air (HEPA) filter is its ability to trap at least 99.97% of airborne particles as small as 0.3 microns, including bacteria, viruses, and other airborne pathogens. This makes HEPA filters essential in medical settings for reducing the risk of airborne infections during surgical procedures and in immunocompromised patient environments. The effectiveness in filtering microscopic airborne pathogens distinguishes HEPA filters from regular air filters that only remove larger particles.

Reference: Medical-Surgical Nursing, 10th Edition.