General Filter  Filter Test Reference and Classification Filter Test  Operating
Type Type Characteristics
Eurovent 4/5 average BS EN779 average
arrestance arrestance
Coarse dust or
primary filter		 EU1 <65 G1 <65 Average value for
arrestance of large
particles using
synthetic dust		 Low efficiency 
EU2 65<80 G2 65<80
Low static pressure drop
EU3 80<90 G3 80<90
EU4 >90 G4 >90
1m2 media area in typical filter unit
Eurovent 4/5 average BS EN779 average
efficiency %  efficiency % 
Fine dust or
secondary filter
EU5 40<60 F5 40<60 Average percentage
value for atmospheric
dust spot efficiency
using atmospheric air		 Medium and higher
efficiencies 
EU6 60<80 F6 60<80
EU7 80<90 F7 80<90
Higher Static
pressure drop
EU8 90<95 F8 90<95
EU9 >95 F9 >95
6m2 + media area in
typical filter unit
Eurovent 4/4 average BS EN779 average
efficiency minimum MPPS% 
High efficiency range
of filters
Higher efficiency
particulate air filter
semi HEPA &
HEPA		 EU10 95<99.9 H10 85 Eurovent 4/4
Sodium chloride test
0.6 micron
EU11 99.9<99.97 H11 95
EU12 99.97<99.99 H12 99.5
EU13
99.99<99.999
 H13 99.95
High static pressure
drop
H14 99.995
EN 1822
Oil mist
aerosol MPPS
300mm filter unit up
to 15m2 media area
Ultra Low
penetration air filter		 U15 99.9995 EN 1822  Highest range of
particulate filters
U16 99.99995
U17 99.999995 Oil mist
aerosol MPPS
High static pressure drop
ULPA
Various designs to suit
specific applications
MPPS - Most Penetrating Particle Size