From EN 779 to ISO 16890
For years Europe used EN 779, which split filters into coarse classes G1-G4 and fine classes F5-F9, plus HEPA H classes under EN 1822. Since 2018, ISO 16890 reports efficiency against defined particle sizes (ePM1, ePM2.5, ePM10, Coarse), which maps closely onto the old letter bands.
Coarse / Primary – G1 to G4
| Class | Average arrestance | Typical use |
|---|---|---|
| G1 | ≤ 65% | Pre-filter, coarse dust |
| G2 | 65-80% | General ventilation pre-filter |
| G3 | 80-90% | Make-up air, paint booths |
| G4 | ≥ 90% | Standard HVAC pre-filter |
Fine / Medium – F5 to F9
| Class | ISO 16890 band | Typical use |
|---|---|---|
| F5 | ePM10 50% | Commercial HVAC final / pre-HEPA |
| F6 | ePM10 60-80% | Schools, offices |
| F7 | ePM2.5 50-70% | Hospitals, labs, food |
| F8 | ePM2.5 70-90% | Pharma, clean support |
| F9 | ePM1 ≥ 90% | Pre-HEPA, critical HVAC |
HEPA / ULPA – H10 to H14, U15 to U17
EN 1822 rates HEPA/ULPA by efficiency at the Most Penetrating Particle Size (MPPS, ~0.1-0.3 µm):
| Class | MPPS efficiency | Use |
|---|---|---|
| H10 | 85% | Clean workstations |
| H11 | 95% | Cleanrooms ISO 7-8 |
| H12 | 99.5% | Cleanrooms ISO 6 |
| H13 | 99.95% | ORs, ISO 5, aseptic |
| H14 | 99.995% | ISO 5, critical aseptic |
| U15-U17 | 99.9995%+ (≥0.12 µm) | ULPA, ISO 3-4 |
Which Label Do You Read?
Specify by the band your standard requires. If a tender cites ISO 16890, ask for ePM1/ePM2.5/ePM10 percentages; if it cites EN 779/EN 1822, use the G/F/H letters above.
