Disposable face masks are classified into Type I, Type II, and Type IIR based on their filtration efficiency, fluid resistance, and intended use. These classifications are primarily defined under the EN 14683 standard (European) and have parallels in other standards like ASTM F2100 (U.S.). Below is a detailed breakdown:
1. Definitions and Key Characteristics
- Type I:
- Definition: Basic surgical mask designed for general public use or low-risk environments.
- Filtration Efficiency: Bacterial Filtration Efficiency (BFE) ≥ 95% .
- Fluid Resistance: None (not splash-resistant).
- Intended Use: Non-medical settings (e.g., public spaces) to limit disease spread by asymptomatic wearers .
- Type II:
- Definition: Higher-performance surgical mask for healthcare settings.
- Filtration Efficiency: BFE ≥ 98% .
- Fluid Resistance: None (lacks splash resistance).
- Intended Use: Moderate-risk medical environments (e.g., general hospital wards) .
- Type IIR:
- Definition: Enhanced surgical mask with fluid resistance for high-risk procedures.
- Filtration Efficiency: BFE ≥ 98% .
- Fluid Resistance: Resists synthetic blood splashes at ≥ 120 mm Hg pressure (per ISO 22609) .
- Intended Use: High-risk clinical settings (e.g., operating theaters, dentistry) where exposure to bodily fluids is likely .
2. Test Standards
All types must comply with EN 14683 (European standard), which includes:
- Bacterial Filtration Efficiency (BFE): Tested using Staphylococcus aureus aerosols .
- Breathability (Differential Pressure): Measures air resistance (Type II/IIR: <60 Pa/cm²) .
- Microbial Cleanliness: ≤30 colony-forming units (cfu/g) per ISO 11737-1 .
- Biocompatibility: Evaluated per ISO 10993-1 for skin contact safety .
- Additional for Type IIR:
- Splash Resistance: Tested per ISO 22609 (120 mm Hg fluid pressure) .
ASTM F2100 (U.S. standard) equivalents:
- Type II ≈ ASTM Level 2 (BFE ≥ 98%, fluid resistance 120 mm Hg) .
- Type IIR ≈ ASTM Level 3 (BFE ≥ 98%, fluid resistance 160 mm Hg) .
3. Applicable Differences
| Feature | Type I | Type II | Type IIR |
|---|---|---|---|
| BFE | ≥95% | ≥98% | ≥98% |
| Fluid Resistance | No | No | Yes (≥120 mm Hg) |
| Layers | 3-ply | 3-ply | 4-ply (extra fluid-resistant layer) |
| Primary Use | Public/low-risk | Healthcare/moderate-risk | High-risk (surgery, dentistry) |
| Regulatory Class | Class I medical device (EU) | Class I (EU) | Class I (EU), FDA-cleared as ASTM Level 2/3 |
4. Key Notes
- Type IIR is WHO-recommended for clinical environments due to its fluid resistance.
- ASTM vs. EN Standards: While EN 14683 focuses on medical masks, ASTM F2100 includes broader levels (1–3) with varying fluid resistance .
- Sterility: These masks are typically non-sterile unless specified for surgical use.
