ULPA filters trap more particles and are smaller than HEPA filters. ULPA filters are 99 to 99.999% effective in removing submicron particles of 0.12 microns in diameter or more, while HEPA filters are 99 to 97% effective in removing particles of 0.3 microns in diameter or more. HEPA filters remain the recommended standard for those responsible for minimizing airborne dust and pathogens during construction in healthcare environments. This reduction is due to the fact that air first passes through the HEPA filter and passes through the UV-C process.
With a similar design compared to a HEPA filter, ultra-low particle air filters (ULPA) have a dense network of randomly arranged fibers. Both HEPA and ULPA filters consist of countless tiny, randomly arranged threads of borosilicate glass microfibers. Today, HEPA and ULPA filters are designed to capture airborne particles and work in a similar way. According to the EPA, a HEPA filter must remove at least 99.97% of the largest particles, at least 0.3 microns in size.
The worst-case particle size is 0.3 micrometers, and that fact helped determine the design parameters of the HEPA filter. HEPA filters are designed for most industrial, military, and government applications, especially in types of manufacturing where airborne particles are constant. Both HEPA and ULPA filters are designed to trap very small contaminant particles from an air stream by forcing air through a fine mesh. Many consider HEPA air purifiers to be the best option, but there is a filter that technically blocks more contaminants carried through the air.
Therefore, the most important thing is to follow the infection control precautions described in the ICRA matrix, such as correctly installing temporary barriers, creating a negative air environment with HEPA-equipped filtration machines, and cleaning with vacuum cleaners with a HEPA filter. HEPA air filters are especially good at removing particles such as mold, pet dander, dust, and other allergens. However, chemicals found in the air, such as VOCs and mists from bacteria and viruses, are too small for HEPA filters to trap and can pass directly to through them.