Table 1.
Comparison of filtration test methods.
| Test | Source | Aerosol | Particle | Particle | Particle | Aerosol | Flow Rate | Test | Max | Sample Type |
|---|---|---|---|---|---|---|---|---|---|---|
| Method | Documents | Type | Size | Charge | Concentration | Detector | (Face Velocity) | Time | Efficiency | (Size) |
| NIOSH NaCl | 42 CFR part 84 | NaCl | 0.075 µm CMD (GSD <1.86) | Neutralized | <200 mg/m3 | Light Scattering photometer | 85 L/min (Face velocity varies between respirators) | Maximum penetration | 99.999% | Respirator (Entire mask) |
| FDA-PFE | 1) FDA Guidance Document (SM 501(k)112) ASTM F 1215-89 (withdrawn)173) ASTM F2100144) ASTM F299912 | Polystyrene latex spheres (FDAGuidance Document) | 0.1 µm(FDA Guidance Document) | Unneutralized(FDA Guidance Document) | Generate 107 - 108 particles/m3 and dilute as needed(ASTM F2299) | Optical particle counter(ASTM F2299) | Face velocity- 0.5–25 cm/sec(ASTMF2299) | 1-5 minInitial efficiency(ASTM F2299) | 99.9%;Increase aerosol concentration to achieve greater efficiencies(ASTM F2299) | Surgical mask (Entire mask)(FDA Guidance Document) |
| ASTM-PFE | ASTM F229912 | Latex spheres | 0.1 to 5.0 µm (Mono-disperse aerosol; MPS | Neutralized | Generate 107 - 108 particles/m3 and dilute as needed | Optical particle counter | Face velocity- 0.5–25 cm/sec | 1–5 min Initial efficiency | 99.9%, Increase aerosol concentration to achieve greater efficiencies | Surgical mask (Mask material) (50–150 mm diameter circle) |
| FDA-BFE | 1) FDA Guidance Document (SM 501(k))112) ASTM F2100143) ASTM F210113 | Staphylo-coccus aureus (ASTM F2101) | 3.0 ± 0.3 µm(MPS)(ASTM F2101) | Undefined(ASTM F2101) | 2200 ± 500 viable particles per test (ASTM F2101) | Six-Stage Viable Particle Cascade Impactor (ASTMF2101) | 28.3 L/min(Face velocity not defined) (ASTM F2101) | 2 min aerosol exposure per test (ASTM 2101) | 99.9% (ASTM F2101) | Surgical mask (Entire mask) (FDA Guidance Document) |
| ASTM-BFE | ASTM F210113 | Staphylo-coccus aureus bacteria | 3.0 ± 0.3 µm MPS | Undefined | 2200 ± 500 viable particles per test | Six-Stage Viable Particle Cascade Impactor | 28.3 L/min (Face velocity not defined) | 2 min aerosol exposure per test | 99.9% | Surgical mask (Mask material) (Test material area not defined; but should be reported) |
| VFE | Not a Standard test method | PhiX174 virus | 3.0 ± 0.3 µm MPS (adapted from ASTM F2101) | Undefined | 1700 – 2000 plaque forming units per test (adapted from ASTM F2101) | Six-Stage Viable Particle Cascade Impactor (adapted from ASTM F2101) | 28.3 L/min (Face velocity < 4.7 cm/sec) (per Nelson Labs) | Not Defined | 99.9% (adapted from ASTM F2101) | Entire mask or 10 × 10 cm mask material (per Nelson Labs) |