HEPA filters are classified into different grades based on their efficiency and performance characteristics. These grades are designated by the acronym “HEPA”; followed by a letter to indicate the filter’s efficiency level. The most common HEPA filter grades include:

HEPA-Type or HEPA-Like: These filters are not true HEPA filters but are often labeled as such. They may have lower efficiency and are not certified to meet the stringent standards of true HEPA filters. They can capture larger particles but may not effectively filter out smaller particles like allergens and
viruses.

True HEPA (HEPA H13 and H14): True HEPA filters are the highest quality and most efficient filters. They are certified to meet specific standards for particle removal. HEPA H13 filters must capture at least 99.95% of particles down to 0.3 micrometers in size, while HEPA H14 filters must capture at least 99.995% of particles of the same size. These filters are commonly used in medical settings, cleanrooms, and other environments where maintaining extremely high air quality is crucial.

HEPA E10 to E12: These filters are used in various industrial applications where high-efficiency particle capture is important. E10 filters capture at least 85% of particles down to 0.3 micrometers, E11 filters capture at least 95%, and E12 filters capture at least 99.5%.

The efficiency of a HEPA filter is only one factor to consider. Proper maintenance, regular filter replacement, and the overall design of the air purification system also play important roles in achieving optimal air quality.