If you want to understand the quality benchmarks for medical masks, you must familiarize yourself with ASTM F2100-21.

ASTM standards are vital to the medical mask industry because they provide strict production guidelines to ensure masks effectively protect wearers from infection. The most critical standard is ASTM F2100, which specifies performance requirements for three different levels of medical masks: Level 1, Level 2, and Level 3. To be legally and safely recognized as a true medical device, a product must successfully pass these rigorous filtration and fluid barrier tests.

ASTM F2100 Performance Requirements at a Glance

The ASTM F2100 standard is widely used in the United States and other countries as the primary guideline for evaluating the performance of medical masks, including those used against the SARS-CoV-2 virus. It offers three levels of protection based on intended use:

Protection Level	Fluid Resistance	BFE / PFE Filtration	Delta P (Breathability)	Ideal Medical Scenarios
Level 1	80 mmHg	≥ 95%	< 5.0 mm H2O/cm²	Low-risk (e.g., basic exams, visitor use)
Level 2	120 mmHg	≥ 98%	< 6.0 mm H2O/cm²	Moderate-risk (e.g., dental procedures)
Level 3	160 mmHg	≥ 98%	< 6.0 mm H2O/cm²	High-risk (e.g., surgeries, trauma care)

Clinical Scenarios: Choosing the Right Protection Level

Matching the right mask to the right clinical environment is the foundation of infection control. Here is when to deploy each ASTM level:

When should you use an ASTM Level 1 mask?

ASTM Level 1 masks provide basic protection and are designed to resist fluid splashes at venous pressure (80 mmHg).

• Ideal Scenarios: Low-risk situations such as standard patient consultations, hospital visitor use, or basic respiratory etiquette in public spaces.

• Key Features: Made from lightweight materials, they offer the highest breathability (lowest Delta P) among medical masks. While they protect against larger respiratory droplets, they are not suited for environments with a high risk of blood or fluid splatter.

When should you use an ASTM Level 2 mask?

ASTM Level 2 masks feature an enhanced barrier construction compared to Level 1 options, designed to resist fluid splashes at arterial pressure (120 mmHg).

• Ideal Scenarios: Moderate-risk environments, such as dental procedures, routine clinical examinations, and minor surgeries.

• Key Features: They maintain a minimum 98% efficiency for both Bacterial Filtration (BFE) and Sub-micron Particulate Filtration (PFE at 0.1 μm). While offering superior protection, they remain optimized for breathability, making them a versatile choice for extended clinical wear.

When should you use an ASTM Level 3 mask?

ASTM Level 3 masks are engineered for high-risk clinical environments where heavy exposure to blood, body fluids, surgical smoke, or aerosols is anticipated.

• Ideal Scenarios: Complex procedures like orthopedic surgeries, trauma care, and environments utilizing high-pressure irrigation.

• Key Features: Featuring a robust, multi-layered construction, these masks provide the maximum barrier protection available (160 mmHg fluid resistance). They maintain a minimum 98% BFE and PFE. While they have a slightly higher breathing resistance, they are the indispensable choice for maximum clinical safety.

Additional Information Regarding ASTM Standards

To achieve certification for a specific performance level, masks must undergo a comprehensive battery of tests designed to quantify their efficacy in protecting the wearer against various airborne contaminants. Among these, the most critical is the Filtration Efficiency test, which evaluates the mask’s capacity to intercept submicron particles from the air. Generally, a mask demonstrating a filtration efficiency of 95% or higher is classified as “medical-grade.”

While the ASTM F2100 standard is primarily engineered for medical face masks, its framework is also applicable to other categories of Personal Protective Equipment (PPE), such as respirators.

In a broader sense, any PPE intended to provide respiratory protection—including defense against dust, smoke, or chemical vapors—should, at a minimum, satisfy the baseline filtration efficiency requirements established within these standardized protocols.

FDA Regulations and Policies Regarding Face Masks

The U.S. Food and Drug Administration (FDA) regulates face masks, medical masks, and surgical masks, classifying them as Class II medical devices. Face masks are designed to protect the wearer from airborne particulates, bacteria, and viruses. Medical masks are intended to protect the wearer from body fluids, including blood, saliva, and mucus. Surgical masks are specifically designed to protect the wearer from surgical instruments and other items that may be contaminated with blood or body fluids.

When hospital administrators evaluate what ppe required means for their specific wards, they rely heavily on how the FDA distinguishes between everyday face masks (like basic cloth or dust masks) and true clinical surgical masks. The key difference? Only true surgical masks are subjected to strict fluid resistance testing, proving they can actually block the dangerous splash of bodily fluids.

How Do ASTM Standards Regulate Mask Performance?

ASTM evaluates mask performance by measuring two primary factors: filtration efficiency and breathability. Filtration efficiency refers to the percentage of particulate matter successfully filtered out by the mask. Breathability refers to the volume of air that can pass through the mask material.

• Filtration Efficiency Testing: Particulates of a standard size are used, and the mask is secured onto a mannequin head. The mannequin is then placed within an aerosol environment to measure the percentage of filtered particles.

• Breathability Testing: A mannequin head is placed inside a sealed chamber, and air is forced through the mask. The volume of air that successfully passes through is then measured.

ASTM has established specific standards for different types of masks. These standards dictate the acceptable materials for mask manufacturing, performance requirements, and precise testing methodologies.

Are Surgical Masks Considered Medical Devices?

Yes. In accordance with the U.S. Code of Federal Regulations 21 CFR 878.4040, surgical masks are classified as Class II medical devices. Both the testing procedures and the materials used must comply with ASTM International standards. Medical masks can be manufactured from a variety of materials, including polypropylene or other synthetic fibers, driven by strict functional requirements.

ASTM Standards and Technical Terminology Explained

(Note: For the European Union market, please refer to corresponding literature on EN 14683.) To truly understand a mask’s specification sheet, you must understand the following testing domains:

1. BFE (Bacterial Filtration Efficiency)

BFE measures a mask’s ability to filter out bacteria.

• Test Method: Exposing the mask to an aerosol containing Staphylococcus aureus.

• Particle Size: 0.6–0.8 microns on average.

• Standard: A minimum of 95% for Level 1, and ≥ 98% for Levels 2 and 3. (Note: ASTM does not recommend the modified Greene & Vesley method for conformity assessment).

2. Particulate Filtration Efficiency (PFE)

PFE measures a mask’s capacity to filter sub-micron particles, serving as a critical indicator for viral and aerosol filtration efficacy.

• Particle Size: Ranges from 0.1 to 5.0 microns.

• Pro-Tip: When comparing test results, always check the specific particle size used. A mask claiming “99% efficiency” against a 5.0-micron particle is vastly different from one tested at 0.1 microns.

When comparing test results, it is crucial to observe the specific particle size used, as larger particles can skew PFE ratings.

3. Fluid Resistance

This denotes a mask’s ability to minimize the transfer of liquid from the outer layer to the inner layer upon exposure to splashes or sprays. Tested using synthetic blood, the pressure values correlate with human blood pressure metrics:

• 80 mmHg = Venous pressure (Level 1)

• 120 mmHg = Arterial pressure (Level 2)

• 160 mmHg = Correlates with high pressures potentially encountered during trauma or high-pressure irrigation procedures, such as orthopedic surgeries (Level 3)

4. Differential Pressure (ΔP)

Delta P is an objective measure of airflow resistance, directly correlating to breathability and comfort.

• Metric: Expressed in millimeters of water per square centimeter (mm H2O/cm²).

• The Trade-off: A lower Delta P value indicates better breathability. Current ASTM standards require a Delta P of < 5.0 for Level 1, and < 6.0 for Levels 2 and 3. Highly protective masks are naturally slightly warmer to wear during long shifts.

5. Flame Spread

Given that hospital environments frequently contain sources of heat, oxygen, and fuel, ASTM standards mandate flame spread testing. All medical masks must be able to withstand exposure to a burning flame for a minimum of three seconds.

6. ISO Certification

In addition to passing the aforementioned tests, all medical masks must undergo skin sensitivity and cytotoxicity testing (ISO 10993-5, -10) to ensure safety, as the manufacturing materials come into direct and prolonged contact with human skin.

Conclusion

Compliance is the Baseline, Protection is the Goal

Understanding the ASTM F2100-21 standard is no longer just for quality assurance specialists—it is essential knowledge for any healthcare administrator, procurement officer, and frontline professional. A medical mask is not merely a piece of fabric; it is a highly engineered Class II medical device designed to break the chain of infection and defend against microscopic threats.

By aligning your PPE choices with the correct ASTM performance levels, you optimize both safety and budget:

Level 1: Your go-to for low-risk, everyday clinical interactions and high breathability.

Level 2: The balanced choice for moderate-risk tasks and dental procedures.

Level 3: The ultimate barrier for high-risk, fluid-intensive surgical environments.

Ultimately, choosing the right medical face mask means prioritizing the health of the wearers. When lives are on the line, there is no room for guesswork. Always verify the BFE, PFE, and fluid resistance ratings, and ensure your facility is stocked with certified, tested medical-grade protection.

References:

• ASTM F2100 – Standard Specification for Performance of Materials Used in Medical Face Masks. (n.d.). ASTM International. Retrieved August 18, 2021, from https://www.astm.org/Standards/F2100.htm

• Bacterial and Viral Filtration Efficiency (BFE/VFE) Tests. (n.d.). Nelson Labs. Retrieved August 18, 2021, from https://www.nelsonlabs.com/testing/bacterial-viral-filtration-efficiency-bfe-vfe/

• Particle Filtration Efficiency (PFE) Testing | Nelson Labs. (n.d.). Nelson Labs. Retrieved August 18, 2021, from https://www.nelsonlabs.com/testing/particle-filtration-efficiency-pfe/