Fine filters are the second-stage defense, capturing microscopic particles (like fine dust and pollen) that larger filters miss. They ensure a high level of air purity and protect sensitive HEPA filters downstream.

EPA (Efficient Particulate Air) filters are classified by European standards (E10-E12) and are highly efficient, capturing 85% to 99.5% of the most penetrating micro-particles (MPPS). They offer excellent filtration and are often used in general HVAC and less critical clean air applications.