Final Filtration
A 0.1 micron absolute-rated final filter cartridge or capsule, prevents suspended solids, particulate matter and bacteria from exiting a lab water purification system along with the purified water. The absolute rating means that nothing larger than 0.1 micron in diameter can pass through the filter.
This is essentially how beer and other liquids are "cold sterilized". The typical final filter capsule is manufactured per GMP standards from USP Class IV materials with no glues or surfactants, and is autoclavable, bubble point testable, and non-pyrogenic.