Filter Classes According EN 779 and EN 1822

Categorization of Filter Classes and Particle Sizes

Particle Size	Examples	Filter Class	Typical Applications
Coarse dust, particle size > 10 µm	-insects -textile fibres and hairs -sand -fly ash -spores, pollen -cement dust	G 1 G 2	-simple applications (e.g. insect screens for compact machinery)
Coarse dust, particle size > 10 µm	-insects -textile fibres and hairs -sand -fly ash -spores, pollen -cement dust	G 3 G 4	-pre-filters and circulation filters for civil defense shelters -exhaust filters for spray painting booths, kitchens, etc. -inlet air filters for air conditioners and compact machines (e.g. window air conditioners, ventilators) -pre-filters for Filter Classes M6 to F8
Fine dust, particle size 1 – 10 µm	-pollen -spores -cement dust -fly ash -bacteria and germs on host particles	M 5	-outside-air inlet filters for rooms with low purity requirements (e.g. factories, warehouse facilities, garages)
Fine dust, particle size 1 – 10 µm	-pollen -spores -cement dust -fly ash -bacteria and germs on host particles	M 5 M 6 F 7	-pre-filters and circulation filters in central ventilation stations -final filters for air conditioning of sales rooms, department stores, offices and certain production plants -pre-filters for Filter Classes F9 to E11
Fine dust, particle size 1 – 10 µm	-oil fumes and agglomerated soot -tobacco smoke -metallic-oxide smoke	F 7 F 8 F 9	-final filters for air conditioning of offices, production plants, control centres, hospitals, EDP centres -pre-filters for filter classes E11 to H13 and activated carbon
Suspended particulates, particle size < 1 µm	-germs, bacteria, viruses -tobacco smoke -metallic-oxide smoke	E 10 E 11 E 12	-final filters for rooms with high and highest purity requirements (e.g. for laboratories, for foods processing, pharmaceutical, fine mechanical, optical or electronics plants or medical facilities)
Suspended particulates, particle size < 1 µm	-germs, bacteria, viruses -tobacco smoke -metallic-oxide smoke	E 11	-final filters for clean rooms, Classes 100,000 or 10,000
Suspended particulates, particle size < 1 µm	-oil fumes and soot in nascent state -radioactive suspended particulates	E 12 H 13	-final filters for clean rooms, Classes 10,000 or 100 -final filters in civil defense shelters -exhaust air filters in nuclear plants
Suspended particulates, particle size < 1 µm	-aerosols	H 14 U 15 U 16	-final filters for clean rooms, Classes 10 or 1

Classification of Coarse and Fine Filters according EN 779:2002

Filter Class	Final Test Pressure Drop	Average Arrestance(Am) of ASHRAE test dust	Average Efficiency(Em) of 0.4 µm particles
	Pa
G1	250	50% ≤ Am < 65%	–
G2	250	65% ≤ Am < 80%	–
G3	250	80% ≤ Am < 90%	–
G4	250	90% ≤ Am	–
F5	450	–	40% ≤ Em < 60%
F6	450	–	60% ≤ Em < 80%
F7	450	–	80% ≤ Em < 90%
F8	450	–	90% ≤ Em < 95%
F9	450	–	95% ≤ Em

Classification of Coarse, Medium and Fine filters according EN 779:2012

Filter Class	Final Test Pressure Drop	Average Arrestance (Am) of ASHRAE test dust	Average Efficiency (Em) of 0.4 µm particles	Minimum Efficiency* of 0.4 µm particles
	Pa
G1	250	50% ≤ Am < 65%	–	–
G2	250	65% ≤ Am < 80%	–	–
G3	250	80% ≤ Am < 90%	–	–
G4	250	90% ≤ Am	–	–
M5	450	–	40% ≤ Em < 60%	–
M6	450	–	60% ≤ Em < 80%	–
F7	450	–	80% ≤ Em < 90%	35%
F8	450	–	90% ≤ Em < 95%	55%
F9	450	–	95% ≤ Em	70%

*Minimum efficiency is the lowest efficiency among the initial efficiency, discharged efficiency and the lowest efficiency throughout the loading procedure of the test.

The characteristics of atmospheric dust vary widely in comparison with those of the synthetic loading dust used in the tests. Because of this the test results according EN 779 do not provide a basis for predicting either operational performance or life. Depending on their design, filters can be operated under actual site conditions to higher final pressure drops than those given here.

Classification of High Efficiency Filters EPA and HEPA according EN 1822:2009

Filter Class	Overall Value	Local Value
Efficiency	Penetration	Efficiency	Penetration
E 10	≥85%	≤15%	–	–
E 11	≥95%	≤5%	–	–
E 12	≥99.5%	≤0.5%	–	–
H 13	≥99.95%	≤0.05%	≥99.75%	≤0.25%
H 14	≥99.995%	≤0.005%	≥99.975%	≤0.025%
U 15	≥99.999 5%	≤0.000 5%	≥99.997 5%	≤0.002 5%
U 16	≥99.999 95%	≤0.000 05%	≥99.999 75%	≤0.000 25%
U 17	≥99.999 995%	≤0.000 005%	≥99.999 9%	≤0.000 1%

Classification according ISO 29463:2011

Filter Class	Overall Value	Local Value
Efficiency	Penetration	Efficiency	Penetration
ISO 15 E	≥95%	≤5%	–	–
ISO 20 E	≥99%	≤1%	–	–
ISO 25 E	≥99.5%	≤0.5%	–	–
ISO 30 E	≥99.90%	≤0.1%	–	–
ISO 35 H	≥99.95%	≤0.05%	≥99.75%	≤0.25%
ISO 40 Hd	≥99.99%	≤0.01%	≥99.95%	≤0.05%
ISO 45 Hd	≥99.995%	≤0.005%	≥99.975%	≤0.025%
ISO 50 U	≥99.999%	≤0.001%	≥99.995%	≤0.005%
ISO 55 U	≥99.999 5%	≤0.000 5%	≥99.997 5%	≤0.002 5%
ISO 60 U	≥99.999 9%	≤0.000 1%	≥99.999 5%	≤0.000 5%
ISO 65 U	≥99.999 95%	≤0.000 05%	≥99.999 75%	≤0.000 25%
ISO 70 U	≥99.999 99%	≤0.000 01%	≥99.999 9%	≤0.000 1%
ISO 75 U	≥99.999 995%	≤0.000 005%	≥99.999 9%	≤0.000 1%