Comparison of EN 1822, ISO 29463, and IEST-RP-CC003.4: Testing, Classification, Particle Size Considerations, and Application Scope

EN 1822, ISO 29463, and IEST-RP-CC003.4 are three key standards for classifying and testing HEPA (High-Efficiency Particulate Air) and ULPA (Ultra-Low Penetration Air) filters. While they share similarities, they differ significantly in testing methods, particle size considerations, classification, and application scope. Below is a comprehensive comparison.

1. Overview of the Standards

Standard	Issuing Organization	Primary Region of Use	Application
EN 1822	European Committee for Standardization (CEN)	Europe	Factory testing and classification of HEPA/ULPA filters
ISO 29463	International Organization for Standardization (ISO)	Global	International equivalent to EN 1822, with extended classifications
IEST-RP-CC003.4	Institute of Environmental Sciences and Technology (IEST)	North America	Field testing and classification of cleanroom-installed filters

✅ Key Differences:

• EN 1822 is mainly used in Europe, whereas ISO 29463 is an international standard applicable globally.

• IEST-RP-CC003.4 is widely used in North America, particularly for testing installed filters in cleanrooms.

• EN 1822 and ISO 29463 focus on factory testing, while IEST-RP-CC003.4 is more relevant for operational verification of filters in real environments.

2. Filter Classification Systems

Each standard has different classification criteria for HEPA and ULPA filters:

EN 1822	E10 - E12 (EPA), H13 - H14 (HEPA), U15 - U17 (ULPA)	Based on MPPS (Most Penetrating Particle Size) efficiency	Manufacturing, pharmaceuticals, cleanrooms
ISO 29463	ISO 15E - ISO 75U	Based on MPPS efficiency (Similar to EN 1822 but with extended subcategories)	Global HEPA/ULPA applications
IEST-RP-CC003.4	Type A - F, J, K, F, G	Based on 0.3 µm and smaller particle efficiency	Cleanroom and installed filter testing

✅ Key Differences:

• EN 1822 and ISO 29463 classify filters based on MPPS efficiency, which is more precise for filter evaluation.

• IEST-RP-CC003.4 uses 0.3 µm efficiency as the primary classification method, which does not account for MPPS variations.

• ISO 29463 extends the classification of HEPA/ULPA filters beyond EN 1822, making it a more globally adaptable standard.

3. Particle Size Considerations in Testing

Each standard uses different particle sizes to evaluate filter performance:

Standard	Test Particle Size Range	Key Particle Size Focus
EN 1822	0.1 - 0.3 µm	MPPS (Most Penetrating Particle Size), typically 0.12 - 0.22 µm
ISO 29463	0.1 - 0.3 µm	MPPS (Similar to EN 1822), more refined efficiency levels
IEST-RP-CC003.4	0.1 - 0.5 µm	Primarily 0.3 µm, with some ULPA filters tested at 0.1 µm

✅ Key Differences:

• EN 1822 and ISO 29463 focus on MPPS, ensuring filters are tested at the most challenging particle size range.

• IEST-RP-CC003.4 primarily relies on 0.3 µm efficiency, which does not always represent the most penetrating particle size.

4. Testing Methods

(1) Flat Sheet Media Test (For Raw Filter Media)

Standard	Is It Required?	Test Method
EN 1822	Yes	MPPS efficiency measurement using test media
ISO 29463	Yes	MPPS efficiency measurement, similar to EN 1822
IEST-RP-CC003.4	No	Does not include raw media testing

✅ Key Differences:

• EN 1822 and ISO 29463 require raw filter media testing, ensuring consistency before final filter assembly.

• IEST-RP-CC003.4 does not require this test, as it focuses on installed filters in cleanrooms.

(2) Overall Filter Efficiency Testing

Standard	Method	Efficiency Measurement
EN 1822	MPPS Efficiency Test	Efficiency at MPPS (typically 0.12 - 0.22 µm)
ISO 29463	MPPS Efficiency Test	Efficiency at MPPS (similar to EN 1822)
IEST-RP-CC003.4	0.3 µm Aerosol Efficiency Test	Efficiency at 0.3 µm (or smaller for ULPA)

✅ Key Differences:

• EN 1822 and ISO 29463 test efficiency at MPPS, ensuring a worst-case penetration evaluation.

• IEST-RP-CC003.4 measures efficiency at 0.3 µm, which may not always be the worst-case penetration size.

5. Application Scope

Standard	Primary Use Case	Industries
EN 1822	Factory testing and classification of new HEPA/ULPA filters	Pharmaceuticals, healthcare, microelectronics, cleanrooms
ISO 29463	Global equivalent of EN 1822, used in both factory and broader international applications	HVAC, manufacturing, semiconductor, healthcare
IEST-RP-CC003.4	On-site/field testing for already installed filters in cleanrooms	Aerospace, semiconductors, cleanrooms, pharmaceutical production

✅ Key Differences:

• EN 1822 is primarily used for factory testing before filters are installed.

• ISO 29463 expands upon EN 1822 and is designed to be globally applicable.

• IEST-RP-CC003.4 is designed for field validation and testing of installed filters, making it more practical for ongoing cleanroom maintenance.

6. Summary of Key Differences

Feature	EN 1822	ISO 29463	IEST-RP-CC003.4
Region of Use	Europe	Global	North America
Classification System	E10-U17	ISO 15E-75U	Type A-F, J, K, F, G
Particle Size Tested	0.1 - 0.3 µm	0.1 - 0.3 µm	0.1 - 0.5 µm
Efficiency Testing Method	MPPS	MPPS	0.3 µm (or smaller for ULPA)
Primary Focus	Factory filter classification	Global HEPA/ULPA classification	Field testing for installed filters
Application	Cleanrooms, pharmaceuticals, microelectronics	Global HVAC, manufacturing, medical	Aerospace, semiconductor, cleanrooms

✅ Conclusion:

• EN 1822 is the European standard primarily used for factory filter classification.

• ISO 29463 extends EN 1822 and is used internationally for HEPA/ULPA filter evaluation.

• IEST-RP-CC003.4 is mainly used in North America for field testing of installed cleanroom filters.

• If selecting a new filter for manufacturing or cleanroom applications, EN 1822 or ISO 29463 should be followed. If verifying installed filters, IEST-RP-CC003.4 is more relevant.