Overview
Medical face masks play a critical role in healthcare by providing source control (helping contain the wearer’s respiratory secretions) and reducing exposure to infectious splashes and sprays during healthcare procedures. ASTM F2100 was developed to define performance expectations for medical face masks. This standard has evolved over time in response to advances in testing methods, regulatory expectations, and real‑world use, particularly during public health emergencies.
ASTM F2100 Updates
ASTM F2100-26 was recently implemented. This revision establishes requirements beyond material performance while maintaining the existing performance tests and classification levels. The update is an important step toward addressing the medical face mask as a finished product and aligns more closely with regulatory expectations for medical devices.
The following are significant updates included in ASTM F2100-26:
- New section for design requirements
- Expanded requirements for labeling
- New section with requirements for user instructions
- Updated expectations for conformity assessment
- Revised and retitled section for sampling and conditioning
Note: The performance levels and associated test methods remain unchanged.
The updates included in ASTM F2100-26 are explained below.
Expanded Scope: Design Requirements
One of the most notable changes in ASTM F2100-26 is the addition of a design requirements section. This includes design controls, such as the following:
- Minimum coverage of the nose and mouth
- Features intended to reduce leakage
- Nose-bridge requirements
- Mask-wearing systems (e.g., earloops or ties)
- Prohibition of valves or vents
- Allowance for integrated face shields
- Consideration of multiple sizes
Enhanced Labeling Requirements
ASTM F2100-26 also expands requirements for labeling. The former “Report” section has been renamed “Labeling” and now includes additional mandatory information beyond the performance-level graphic, manufacturer, product name, and lot number. New labeling requirements include the following:
- Date of manufacture
- Expiration date (if applicable)
- Size (if applicable)
- Statement of conformity to ASTM F2100
- Single-use indication
- Storage conditions
Requirements for User Instructions
In addition, a new section with requirements about user instructions has been added to ASTM F2100-26. Manufacturers must now provide instructions covering the following:
- Size selection (if applicable) and fit adjustment
- Donning and doffing instructions
- End-of-life indicators (e.g., expiration)
- Disposal instructions
- Product limitations
Updated Expectations for Conformity Assessment
ASTM F2100-26 updates the conformity assessment approach to require Model B controls under ASTM F3050, Guide to Conformity Assessment of Personal Protective Clothing and Equipment, rather than the previously referenced Model A, which represents the lowest level of conformity. For those unfamiliar with ASTM F3050: This standard provides a structured framework for demonstrating and communicating compliance to personal protective equipment (PPE) standards.
While a declaration of conformity is required under both models, Model B adds expectations for design, labeling, and user instructions, which are now included in ASTM F2100-26. Model B also requires the supplier to maintain a quality management system with ISO 9001 accreditation.
Sampling and Conditioning Updates
The “Sampling” section in ASTM F2100 has been revised and retitled “Samples, Specimens, and Conditioning.” The update clarifies that testing is expected to be performed on complete, finished medical face masks, rather than on materials alone. It also states conditioning requirements following referenced test methods.
Now that you are familiar with the updates in ASTM F2100-26, you can read on to learn about the evolution of the standard.
Evolution of ASTM F2100
It became clear over 25 years ago that a consistent standard for medical face masks was essential. What began as a material-focused specification has steadily matured into a comprehensive product standard. Below is a summary of the key milestones in the evolution of ASTM F2100.
2001
ASTM F2100 emerged to replace the long‑standing, retired U.S. Military Specification (MIL-M-36954) for surgical masks. Before this, even though the FDA regulated surgical masks as Class II medical devices, manufacturers relied on a mix of legacy military specifications, internal criteria, and individual test methods. ASTM F2100 was created to replace the outdated military specification with an industry, consensus-based standard focused on measurable performance, risk-based classification, and alignment with FDA regulatory expectations. ASTM F2100 became internationally relevant.
2003
The standard introduced guidance emphasizing that mask selection should be based on exposure risk. It also added the requirement for synthetic blood penetration testing to lower barrier levels—80 mmHg for general use (currently level 1) and 120 mmHg for sub-micron filtering (currently level 2). The existing fluid-resistant level (currently level 3) was increased from 120 mmHg to 160 mmHg.
2004
ASTM F1215 was replaced with ASTM F2299, as ASTM F1215 was withdrawn. While the testing methods remain unchanged, the title and terminology were revised to reflect materials used in medical face masks versus flat sheet filter media. The barrier-level characteristic terminology was updated from “general use” (currently level 1), “sub-micron filtering” (currently level 2), and “fluid resistant” (currently level 3) to “low” (currently level 1), “moderate” (currently level 2), and “high” (currently level 3) barrier.
2007
Minor updates were made to definitions for medical face masks and protective clothing. In 2011 the barrier levels were redefined as level 1, 2, and 3. A new requirement was added for level 1 masks to achieve ≥95% sub-micron filtration efficiency, which had not been previously required. Additionally, manufacturers were required to include a graphic representation of the mask’s performance level, improving transparency for end users.
2019
The retired MIL-M-36954C method for measuring differential pressure (Delta P) was replaced with EN 14683:2019 Annex C. This change was driven by improvements within EN 14683: 2019 to testing equipment and procedures, such as mechanical clamping and the use of mass flow meters, which reduced variability and leaks. As a result, the specifications were updated from <4.0mmH2O/cm2 (level 1) and <5.0mmH2O/cm2 (level 2, 3) to <5.0mmH2O/cm2 (level 1) and <6.0mmH2O/cm2 (level 2, 3) to align with the method improvements.
2020
This year’s revision clarified that ASTM F2100 does not address respiratory protection and reinforced the concept of source control. Definitions were expanded to include both surgical and procedure masks, and it was explicitly stated that medical face masks are not respirators. This clarification was particularly important during the COVID-19 pandemic, when mask usage surged and distinctions between mask types became critical for public understanding and regulatory compliance.
2021
Biocompatibility testing was added, requiring evaluation per ISO 10993 for long-term exposure. This change aligned with FDA requirements for Class II medical devices. A conformity assessment process was also introduced, mandating testing at ISO 17025-accredited labs and adherence to ASTM F3050 Model A. These additions aimed to strengthen oversight and ensure consistent product quality.
2023
This update replaced ASTM F2299 with the more stringent ASTM F3502 method for sub-micron filtration efficiency. This method uses NaCl particles and tighter controls, such as face velocity, to yield more accurate and comparable results across mask types. Because this new method produced lower filtration values for the same materials, the specification requirements were adjusted accordingly from ≥95% (level 1) and ≥98% (level 2, 3) to ≥80% and ≥85% (level 2, 3).
2025
EN 14683 Annex C was revised to correct a calculation error in the differential pressure method. The previous approach incorrectly divided by the test area, squaring the denominator. The updated method removed this step, aligning with the correct definition of differential pressure as force per unit area. Specification requirements were adjusted with this calculation update from <5.0mmH2O/cm2 (level 1) and <6.0mmH2O/cm2 (level 2, 3) to <24.5mmH2O/cm2 (level 1) and <29.4mmH2O/cm2 (level 2, 3).
2026
This was a major revision that converted the standard from a materials specification to a full product standard, establishing requirements beyond material performance. The new revision added design, labeling, user instructions, and additional conformity-assessment requirements, but the core performance testing and classification levels have stayed the same. This is a big step to address the entire product. Requirements and recommendations have been added to align more closely with regulatory expectations for medical devices.
Summary
Today, ASTM F2100-26 provides a comprehensive framework for medical face masks. Its evolution reflects lessons learned from decades of use in healthcare settings, advances in test methodology, and the critical role masks play in infection control. The transition from a material-focused specification to a product standard positions ASTM F2100 to better support manufacturers, regulators, and healthcare providers in ensuring safe and effective medical face masks.
At Nelson Labs we will be happy to assist you with your ASTM F2100-related projects. If you would like assistance, please contact us at [email protected].
