All Dyson Airblade™ hand dryers are fitted with sealed HEPA filters as standard. Meaning they are capable of catching 99.97% of particles, down to 0.3 microns, including bacteria and viruses. HEPA is defined as a filter that captures 99.97% of particles down to 0.3 microns and is tested using standard IEST-RP-CC001.6. Standard EN1822-5 further tests filters for capture of 99.95% of particles of the most penetrating size, usually around 0.1 microns. Dyson HEPA filters pass both of these tests ensuring that users can be confident they are drying their hands with HEPA purified air. Filters that do not meet these stringent test standards can be less effective at removing potentially harmful particles from the environment.