ASTM F2100 in Practice: BFE, PFE and Fluid Resistance Testing

Quick Summary: ASTM F2100 is the consensus standard that defines how medical face masks are classified in Canada and the United States, using four laboratory tests — bacterial filtration efficiency (BFE), particulate filtration efficiency (PFE), fluid resistance, and differential pressure (breathability). A mask's Level 1, 2, or 3 designation is not a marketing tier; it is the outcome of these standardized tests. For Canadian clinics that specify masks for clinical use, understanding what each test measures is the difference between buying a verified barrier and buying a face covering.

Why ASTM F2100 Is the Anchor Standard

Before a medical face mask can responsibly be described as "Level 2" or "Level 3," someone has to define what those levels mean. ASTM F2100 does that work. Published by ASTM International, it specifies the performance requirements and test methods for materials used in medical face masks, assigning them to three levels based on how they perform against a defined test battery. It is the standard that Health Canada-aligned procurement documents cite when they specify masks for clinical use in Canada, and it is the reference point that lets a buyer compare one mask to another on the same scale.

The value of F2100 is that it turns subjective words — "fluid-resistant," "breathable," "high-filtration" — into reproducible numbers. Two masks from two different manufacturers can be placed side by side and compared directly because both were pushed through the same four tests under the same conditions. Without that, "Level 3" is just a word on a box.

The Four Tests, One at a Time

Bacterial Filtration Efficiency (BFE)

BFE measures how well the mask material blocks bacteria-carrying particles, typically using a Staphylococcus aureus aerosol challenge under defined conditions (ASTM F2101 is the reference method). The result is expressed as a percentage — the fraction of bacteria-sized particles the material filters out. ASTM F2100 sets the BFE floor at ≥95% for Level 1 and ≥98% for Levels 2 and 3. BFE is the most commonly quoted metric on mask packaging, and for good reason: it speaks directly to the mask's ability to reduce droplet-transmitted particles, the primary concern in routine clinical droplet precautions.

Particulate Filtration Efficiency (PFE)

PFE tests against sub-micron particles — usually a polydisperse latex aerosol with a controlled particle size (often 0.1 micron) — rather than bacteria-sized droplets. This is a harder challenge because the particles are smaller and can slip through pathways that would trap larger droplets. Level 1 masks require a PFE of at least 95% at the specified particle size; Level 2 and Level 3 raise the bar to 98% or higher. The distinction matters in settings where fine aerosol is a concern, and it is why PFE, not BFE, is the more informative number when comparing masks for anything beyond basic droplet protection.

Fluid Resistance (Synthetic Blood Penetration)

This test, based on ASTM F1862, evaluates how well the mask's outer material resists penetration by a synthetic blood solution sprayed at a defined pressure (80 mmHg, 120 mmHg, or 160 mmHg depending on level). It simulates the splash of blood or body fluid that occurs during procedures. Level 1 is tested at 80 mmHg, Level 2 at 120 mmHg, Level 3 at 160 mmHg. This is the test that separates a "procedural" mask from a mask genuinely suited to a splash-risk environment — and the one most often overlooked when a buyer shops by BFE alone.

Differential Pressure (Breathability, Delta P)

Differential pressure (often written ΔP) measures airflow resistance in millimetres of water per square centimetre. A lower ΔP means the mask is easier to breathe through; a higher ΔP means more resistance. F2100 sets a ceiling on ΔP (typically under 4.0 mm H₂O/cm² for Level 1 and under 5.0 mm H₂O/cm² for Levels 2 and 3 at the flow rates specified) so that higher-filtration masks do not become unwearable. This is the comfort axis of the standard — a mask can pass all three barrier tests and still fail if it is too hard to breathe through for a full clinical shift.

What the Levels Actually Require

The logic threaded through the levels is cumulative: each step up mainly trades fluid resistance and slightly higher filtration for a modest increase in breathing resistance. A Level 1 mask is a reasonable general barrier for low-acuity contact; Level 3 is the choice when a procedure generates visible splatter. Most Canadian dental and ambulatory clinics operate comfortably at Level 2 or Level 3 depending on procedure mix, which is why masks labelled to a confirmed F2100 level are the procurement default over unclassified "3-ply" masks.

Reading the Label Without Being Misled

Because F2100 is a material standard, a common confusion is between "3-ply" and "Level 2/3." Ply count describes how many layers of material make up the mask; the ASTM level describes how the finished material performed on the test battery. A 3-ply mask can be Level 1, 2, or 3 — or, critically, unclassified if it was never tested. "3-ply" tells you nothing about filtration by itself. A mask sold with a ply count but no ASTM level, or with a declared level but no test evidence behind it, should be treated as unverified for clinical use.

The same caution applies to the difference between a surgical mask and a respirator. ASTM F2100 covers medical face masks, which fit loosely and provide barrier protection. N95 respirators are a different class, tested against a fit-tested filtration standard, and are not graded by F2100. Procurement teams that need respiratory protection should specify respirators separately; F2100 masks are the right tool for droplet and splash barriers in routine care.

The Regulatory Layer Above the Standard

ASTM F2100 tells you how the material performs; it does not, by itself, license the mask for sale as a medical device. In Canada, medical face masks supplied for clinical use fall under Health Canada's medical device framework, and a responsible Canadian distributor holds the appropriate establishment licensing. The ASTM level and the regulatory standing are two separate questions that belong on every procurement checklist.

This distinction explains a real pattern in the supply chain: a mask can carry a credible "Level 2" on its packaging and still not be legally supplied for medical use in Canada if the distributor is unlicensed. Conversely, a licensed distributor will typically make both its ASTM classification and its establishment licensing explicit, because clinical buyers ask for both. The same verification discipline shows up in the hospital epidemiology literature, for example in the Infection Control & Hospital Epidemiology journal's analyses of mask and respirator procurement. When you are comparing quotes, treat "ASTM F2100 Level X" and "licensed Canadian distribution" as two separate boxes that both need to be ticked.

The same separation applies to sourcing claims like "made in Canada," "hospital grade," or "medical grade." None of these is a standardized performance measure the way F2100 is. "Made in Canada" speaks to origin, not barrier; "hospital grade" is marketing language with no consensus definition; "medical grade" should point back to a device classification, not stand alone. A disciplined spec sheet anchors on the F2100 level as the performance truth, then layers regulatory standing and origin on a second, clearly-labelled tier. Sustainable-procurement groups such as Health Care Without Harm add a third tier for disposables: verified performance first, then waste and material considerations.

For a Canadian clinic building a defensible supply list, the summary is compact: require a declared ASTM F2100 level, verify the test report when the claim matters, confirm Health Canada standing, and match the level to the clinical exposure. Four checks, each independent, none substitutable for another.

Putting the Standard to Work in a Canadian Clinic

For a Canadian facility, the practical path is straightforward. First, define the exposure: general contact and examination work rarely needs more than Level 1, while dental hygiene, minor procedures, and anything generating splash call for Level 2 or Level 3. Then, require a declared ASTM F2100 level on every mask spec, and ask for the test report if the claim is not immediately credible. Finally, confirm the mask sits within Health Canada's medical device framework before it joins your supply list.

The Public Health Agency of Canada's routine practices and additional precautions guidance describes mask selection in exactly these risk-based terms, and it is the document a cautious procurement lead will want on file. The CDC's isolation precautions guideline frames the same risk-based mask selection, and facility-level compliance studies in the CDC Emerging Infectious Diseases journal show why documented standards beat box-label claims. Clause-level precision on the F2100 test methods is available directly from ASTM and ASTM F2101, the BFE reference method.

CliniEco Medical carries ASTM-classified masks across the level range, including the Level 3 three-ply mask for procedure-heavy settings and the Level 1 procedural mask for general use, with Aurelia Level 2 masks made in Canada for facilities that want a domestic-sourced option.

Frequently Asked Questions

What does ASTM F2100 actually test?

ASTM F2100 defines four performance criteria for medical face mask materials: bacterial filtration efficiency (BFE), particulate filtration efficiency (PFE), fluid resistance (synthetic blood penetration), and differential pressure (breathability). A mask's Level 1, 2, or 3 rating is assigned based on its results across all four tests.

Is a 3-ply mask the same as a Level 3 mask?

No. "3-ply" describes the number of material layers; the ASTM level describes how the mask performed on standardized filtration and fluid-resistance tests. A 3-ply mask can be Level 1, 2, or 3, or unclassified if it was never tested. Ply count by itself does not guarantee any filtration performance.

What level mask do dental clinics need?

Dental procedures routinely generate splash and aerosol, so dental settings typically specify Level 2 or Level 3 masks. Level 3 is indicated when the procedure produces visible splatter of blood or body fluid. The choice should follow the exposure risk, which is how the PHAC routine practices guidance frames mask selection.

What is the difference between BFE and PFE?

BFE measures filtration of bacteria-sized particles using a bacteria aerosol challenge, while PFE measures filtration of smaller sub-micron particles. PFE is the harder challenge and the more informative number when comparing masks for anything beyond basic droplet protection. Both are required under ASTM F2100.

Does ASTM F2100 apply to N95 respirators?

No. ASTM F2100 covers medical face masks, which fit loosely and provide barrier protection. N95 respirators are a separate class tested to a fit-tested filtration standard and are not graded by F2100. Facilities needing respiratory protection should specify respirators separately.

Where can Canadian clinics buy ASTM-classified masks?

CliniEco Medical supplies Level 3, Level 1, and Aurelia Level 2 masks made in Canada, with test documentation available for procurement review.

Are medical face masks regulated in Canada?

Yes. Medical face masks supplied for clinical use are regulated as medical devices in Canada. CliniEco Medical is a licensed medical device establishment (MDEL #35334). A verified mask will have both a declared ASTM F2100 level and a legitimate regulatory standing.

How do I choose between Level 1, 2, and 3?

Match the level to fluid-exposure risk: Level 1 for low-splash general contact, Level 2 for moderate splash, and Level 3 for heavy splash during procedures. The higher levels add fluid resistance (tested at 80, 120, and 160 mmHg respectively) at a modest cost in breathability, so select the lowest level that safely covers the actual task.

Choosing a mask is ultimately a risk-mapping exercise: identify the fluid exposure your procedures actually generate, then select the lowest F2100 level that covers it without needlessly sacrificing breathability or budget. A clinic that standardizes on Level 2 for routine care and reserves Level 3 for the splash-prone procedures gets the protection it needs without over-spending — and every mask on its shelf carries a documented reason for being there.

References

1. ASTM International — ASTM F2100 Standard Specification for Performance of Materials Used in Medical Face Masks, store.astm.org
2. ASTM International — ASTM F2101 Test Method for BFE, store.astm.org
3. ASTM International — ASTM F1862 Test Method for Resistance of Medical Face Masks to Penetration by Synthetic Blood, store.astm.org
4. Public Health Agency of Canada — Routine Practices and Additional Precautions, canada.ca
5. Health Canada — Medical Devices, canada.ca
6. Antimicrobial Resistance & Infection Control (Springer Open), link.springer.com
7. Journal of Hospital Infection (Elsevier), sciencedirect.com
8. American Journal of Infection Control (Elsevier), sciencedirect.com
9. CDC — Infection Control, cdc.gov
10. World Health Organization — Bulletin of the World Health Organization, who.int
11. Infection Control & Hospital Epidemiology (Cambridge), cambridge.org
12. CDC Emerging Infectious Diseases, wwwnc.cdc.gov
13. Journal of Polymers and the Environment (Springer), link.springer.com
14. Health Care Without Harm, noharm.org
15. CDC — Isolation Precautions Guideline, cdc.gov

Last updated: August 31, 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).