EN 1822 / HEPA / ULPA / MPPS
EN 1822 is the core European standard, developed by CEN, for testing and classifying HEPA/ULPA high-efficiency filters. It grades filters from H13 to U15 by MPPS (Most Penetrating Particle Size), and pairs this with the scan method (leak test) to ensure zero leakage — making it widely used in high-cleanliness fields such as cleanrooms, medical facilities, and microelectronics.
EN 1822 is the core standard, developed by the European Committee for Standardization (CEN), for testing and classifying High-Efficiency Particulate Air (HEPA) and Ultra-Low Penetration Air (ULPA) filters. The standard is primarily applied in fields with extremely high air-cleanliness requirements — such as cleanrooms, medical facilities, the pharmaceutical industry, and microelectronics manufacturing.
I. Latest Edition: EN 1822:2009
The standard is divided into the following five parts:
- EN 1822-1: Classification, performance testing, and marking
- EN 1822-2: Aerosol generation, measuring equipment, and particle-counting statistics
- EN 1822-3: Testing of flat-sheet filter media
- EN 1822-4: Leakage testing (scan method)
- EN 1822-5: Efficiency testing of filter elements
II. Core Content
1. Filtration Efficiency and Classification
- HEPA/ULPA filters are divided into different grades according to their filtration efficiency (e.g., H13, H14, U15).
- MPPS (Most Penetrating Particle Size): The standard requires testing the filter’s filtration efficiency against particles at the most penetrating particle size within the 0.1–0.3 µm range.
- Basis for classification:
①HEPA: efficiency ≥ 99.95% (H13) or ≥ 99.995% (H14).
②ULPA: efficiency ≥ 99.9995% (U15) and above.
2. Leakage Testing
- The scan method is used to detect any local defects or leakage in the filter.
- The maximum permissible penetration at a leak point must not exceed a certain multiple of the filter’s integral test efficiency (for example, for an H14 filter, the leak point must not exceed 0.025%).
3. Test Method
- An aerosol (such as DEHS or PAO) is used as the test medium.
- A particle counter measures the upstream and downstream particle concentrations, and the filtration efficiency is calculated from the two values.
III. Application Fields
- Medical industry: operating rooms, aseptic pharmaceutical workshops.
- Electronics manufacturing: chip production, precision-instrument assembly.
- Nuclear energy and biosafety: protection against radioactive particles or pathogens.
- Aerospace: high-cleanliness environment control.
IV. Relationship with Other Standards
- ISO 29463: an analogous standard published by the International Organization for Standardization (ISO); its test methods are partially compatible with those of EN 1822.
- IEST RP-CC034: a guideline of the U.S. Institute of Environmental Sciences and Technology (IEST), often used to supplement EN 1822.
