Ultra-low particulate air
ULPA is an acronym for "Ultra Low Particulate Air (filter)" An ULPA filter can remove from the air at least 99.999% of dust, pollen, mold, bacteria and any airborne particles with a size of 100 nanometres (0.1 µm) or larger.
- "IEST Recommended Practices". IEST. 2007-12-03. Retrieved 2008-01-14.