ASTM F2101-25 PDF

Full title and description

Standard Test Method for Evaluating the Bacterial Filtration Efficiency (BFE) of Medical Face Mask Materials, Using a Biological Aerosol of Staphylococcus aureus — designation ASTM F2101-25. The method describes a laboratory procedure for generating a Staphylococcus aureus aerosol challenge and determining the ratio of upstream to downstream bacterial concentration to report percent bacterial filtration efficiency of mask materials.

Abstract

ASTM F2101-25 is a test method (not a performance specification) used to measure Bacterial Filtration Efficiency (BFE) of medical face mask materials. The test uses S. aureus as the biological challenge, a defined aerosol generation and sampling arrangement, and reports efficiency as the percentage reduction of viable bacteria passing through the specimen. The method is intended to evaluate material barrier performance (not mask fit or respirator certification) and can be used for gowns, drapes and other porous medical barrier materials where appropriate.

General information

• Status: Active (current standard, F2101-25).
• Publication date: January 1, 2025 (F2101-25; ASTM record shows update in early 2025).
• Publisher: ASTM International.
• ICS / categories: 11 — Health care technology; commonly classified under ICS 11.140 (Hospital equipment).
• Edition / version: F2101-25 (2025 edition).
• Number of pages: 7 pages (concise test method document).

Key bibliographic details (designation and DOI) and the short-format text are recorded in the ASTM registry for F2101-25.

Scope

This test method measures bacterial filtration efficiency (BFE) of medical face mask materials by comparing an upstream bacterial aerosol challenge to the downstream residual viable bacterial concentration. The procedure uses Staphylococcus aureus as the challenge organism, operates at a respiration-representative flow rate (1 ft3/min or 28.3 L/min) through a cascade impactor, and reports efficiencies up to the method limit (maximum determinable ~99.9%). The standard notes it does not address breathability, mask fit/seal (respirator certification), or all possible exposure conditions; users should select appropriate preconditioning if physical/chemical/thermal stresses are relevant.

Key topics and requirements

• Biological challenge organism: Staphylococcus aureus (clinical relevance and repeatable culture/assay procedures).
• Aerosol generation and challenge level control (typical challenge counts and nebulization technique specified in method).
• Test flow rate and sampling: 28.3 L/min (1 ft3/min) through the specimen and cascade impactor arrangement to collect viable particles downstream.
• Calculation and reporting of percent BFE (ratio of upstream to downstream viable counts; maximum measurable ~99.9%).
• Requirements for specimen conditioning or pretreatment if evaluating effects of storage, wetting, laundering, sterilization, or mechanical stress.
• Statistical reporting guidance for quality control (sample numbers, mean, standard deviation; reference sampling standards such as ANSI/ASQ Z1.4 or ISO 2859-1 where applicable).

The list above summarizes the principal technical elements specified in the method; the full text contains procedural details, acceptance of SI/inch‑pound units, and safety/responsibility notes.

Typical use and users

Typical users include medical mask and barrier-material manufacturers (for product development and quality control), third‑party testing laboratories, regulatory reviewers and standards committees, and healthcare product designers comparing material barrier performance. The method is often used together with other mask-related tests (PFE, differential pressure, synthetic blood penetration) when determining overall mask performance levels.

Related standards

ASTM F2101 is commonly used alongside: ASTM F2100 (Specification for Performance of Materials Used in Medical Face Masks), ASTM F2299 (Particulate Filtration Efficiency using latex spheres), ASTM F1862 (Resistance to Penetration by Synthetic Blood), EN 14683 (medical face masks — requirements and test methods), and relevant ISO standards for sampling and biocompatibility (ISO 2859‑1, ISO 10993 series). For conformity assessment and sampling guidance see ANSI/ASQ Z1.4 and ISO 2859‑1.

Keywords

Bacterial Filtration Efficiency; BFE; medical face mask materials; Staphylococcus aureus; aerosol challenge; cascade impactor; mask material testing; ASTM F2101-25; barrier performance.

FAQ

Q: What is this standard?

A: ASTM F2101-25 is a standardized laboratory test method for evaluating the bacterial filtration efficiency (BFE) of medical face mask materials using a biological aerosol of Staphylococcus aureus.

Q: What does it cover?

A: It specifies how to generate a S. aureus aerosol challenge, how to present that challenge to a material specimen, how to collect and count viable downstream organisms, and how to calculate and report percent BFE. It does not set pass/fail acceptance levels (those are specified by product specifications such as ASTM F2100) and it does not evaluate mask fit or respiratory certification.

Q: Who typically uses it?

A: Manufacturers, contract and independent test laboratories, regulatory reviewers, and standards/quality professionals use the method for product development, routine quality control, and as part of a battery of tests that inform mask performance claims.

Q: Is it current or superseded?

A: As of the 2025 designation it is the current active test method (ASTM F2101-25). Users should confirm the latest status via the ASTM registry for any updates or corrigenda.

Q: Is it part of a series?

A: F2101 is usually applied together with related ASTM and international standards that together characterize mask performance (for example ASTM F2100, F2299, F1862 and EN 14683). These documents together address barrier performance, particulate filtration, fluid resistance and flammability used to classify surgical/medical mask levels.

Q: What are the key keywords?

A: Key terms include Bacterial Filtration Efficiency (BFE), Staphylococcus aureus, aerosol challenge, medical face mask materials, cascade impactor, percent filtration efficiency, and test method.