Face Mask BFE and PFE Testing: What the Numbers Actually Mean

Q: How to Verify a Supplier’s Test Report

Anyone can print “BFE ≥ 98%” on a box; the report behind it matters. Four checks catch weak documentation. Who ran the test? Prefer independent labs with ISO/IEC 17025 accreditation over in-house testing. Which standard and edition? The report should cite the exact methods and edition — ASTM F2100, F2101, F2299. Is the sample traceable? The report should name the product, the lot, and the test date — not a “similar” mask. Do the numbers line up? Label claims should match the report within rounding; 98% on a label against 95% on the report is a red flag.

Q: Is the difference between 98% and 99% BFE significant?

Not in any practical sense. Both clear the 98% threshold, and the gap between two independently tested materials sits within normal variation. More important: the number comes from a compliant ASTM F2101 test — and the mask fits.

Q: Can a Level 3 mask replace an N95 respirator?

No. ASTM F2100 Level 3 describes mask material performance; NIOSH certification under 42 CFR Part 84 covers respirators, including fit testing. Where respirators are required, source and fit-test them separately.

Q: How do I read a mask test report quickly?

Find the four numbers — BFE, PFE with its particle size, differential pressure, fluid resistance — then confirm the standard, edition, lab, and lot. If any are missing, request the full report before ordering.

August 16, 2026

Quick Facts: BFE and PFE at a Glance

BFE — bacterial filtration efficiency, per ASTM F2101. Minimum: 95% (Level 1), 98% (Levels 2–3).
PFE — particulate filtration efficiency, per ASTM F2299 (0.1 µm latex particles). Minimum: 95% (Level 1), 98% (Levels 2–3).
ASTM F2100 — the umbrella standard combining BFE, PFE, breathability, and fluid resistance into Levels 1–3.
Level 3 is not an N95. ASTM F2100 tests material; NIOSH tests respirators and fit under 42 CFR Part 84.

Every box of medical face masks carries numbers — BFE 98%, PFE 98%, ASTM F2100 Level 3 — but those figures rarely mean what they seem to. This guide is for procurement and compliance officers who read mask test reports. By the end, you will know what each number measures and how to spot a report that does not back its label.

What BFE Actually Measures

BFE stands for bacterial filtration efficiency: the share of bacteria-sized particles a mask material captures in a standard aerosol challenge.

The test follows ASTM F2101. A Staphylococcus aureus suspension is aerosolized and drawn through the material; the bacteria that pass through are counted against the challenge. A BFE of 98% means the material captured 98% of them.

Two limits matter. BFE is a material property, not a measure of fit or edge leakage, and it does not predict real-world droplet capture. ASTM F2100 minimums: 95% for Level 1, 98% for Levels 2–3.

CliniEco 3-ply ASTM Level 1 procedural face masks, 50-pack

What PFE Actually Measures

PFE stands for particulate filtration efficiency. Where BFE uses bacteria, PFE uses 0.1 micrometre latex spheres, per ASTM F2299, to test submicron particle capture.

The 0.1 µm size matters: it is far smaller than most respiratory droplets, so a material that filters 0.1 µm particles generally captures larger ones. PFE ≥98% at 0.1 µm is the most common Level 2 and 3 claim.

One caveat: PFE is measured on flat samples at a fixed flow rate — not on a face.

The Full ASTM F2100 Requirements by Level

Property	Level 1	Level 2	Level 3
BFE — ASTM F2101	≥ 95%	≥ 98%	≥ 98%
PFE @ 0.1 µm — ASTM F2299	≥ 95%	≥ 98%	≥ 98%
Differential pressure (breathability)	< 4.0 mm H₂O/cm²	< 5.0 mm H₂O/cm²	< 5.0 mm H₂O/cm²
Synthetic blood penetration resistance	80 mmHg	120 mmHg	160 mmHg

Per ASTM F2100-19 / F2100-20, Standard Specification for Medical Face Mask Materials.

Three details stand out. Level 1 to 2 is a filtration jump: BFE and PFE go from 95% to 98%. Level 2 to 3 is a fluid-resistance jump: filtration holds while blood resistance climbs to 160 mmHg. Breathability also tightens, which keeps Level 1 the standard choice for long shifts.

CliniEco 3-ply medical face mask bulk clinic pack, 50 masks per box

What These Numbers Mean for Procurement

Level 3 is not an N95. Both involve similar numbers but answer different questions. ASTM F2100 measures how well the mask material filters a measured aerosol; NIOSH certification under 42 CFR Part 84 tests the complete respirator, including fit on a panel of subjects. A Level 3 mask has no fit-testing requirement.

Three rules for comparing supplier reports:

Compare like with like. An ASTM F2101 BFE is comparable only to another ASTM F2101 result — not to an in-house “modified” method.
Check the particle size. PFE at 0.1 µm is not comparable to PFE at 3.0 µm; the smaller challenge is harder.
Check the standard version. ASTM F2100-19 and -20 differ from older editions; a superseded citation deserves a question.

How to Verify a Supplier’s Test Report

Anyone can print “BFE ≥ 98%” on a box; the report behind it matters. Four checks catch weak documentation.

Who ran the test? Prefer independent labs with ISO/IEC 17025 accreditation over in-house testing.
Which standard and edition? The report should cite the exact methods and edition — ASTM F2100, F2101, F2299.
Is the sample traceable? The report should name the product, the lot, and the test date — not a “similar” mask.
Do the numbers line up? Label claims should match the report within rounding; 98% on a label against 95% on the report is a red flag.

Related reading

Frequently Asked Questions

Is the difference between 98% and 99% BFE significant?

Not in any practical sense. Both clear the 98% threshold, and the gap between two independently tested materials sits within normal variation. More important: the number comes from a compliant ASTM F2101 test — and the mask fits.

Can a Level 3 mask replace an N95 respirator?

No. ASTM F2100 Level 3 describes mask material performance; NIOSH certification under 42 CFR Part 84 covers respirators, including fit testing. Where respirators are required, source and fit-test them separately.

How do I read a mask test report quickly?

Find the four numbers — BFE, PFE with its particle size, differential pressure, fluid resistance — then confirm the standard, edition, lab, and lot. If any are missing, request the full report before ordering.

Reading the Numbers Is Only Half the Job

Choosing a mask starts with reading its numbers correctly — and ends with a supplier who backs every figure with a dated, third-party report. CliniEco publishes the filtration data behind its masks and stocks ASTM Level 3 masks, Level 1 procedural masks, and bulk clinic packs. Talk to our team to match the right level to the right setting.