FILTRATION FOR RESPIRATORY PROTECTION: STANDARDS AND TSI® SOLUTIONS

Masks and Respirators: Navigating Standards and Testing Equipment

The global demand for respiratory protection and barrier devices has increased significantly during the COVID-19 pandemic, leading to higher production volumes and new market entries. Testing standards for these devices are evolving, adding complexity for manufacturers and users.

While respirator testing has remained relatively stable, testing for other device types has seen changes. Barrier face coverings, commonly known as facemasks used in public spaces, now have a formal testing standard (ASTM F3502). The US testing standard for medical masks (ASTM F2100) was undergoing revision as of Q2 2021.

Understanding which testing standards apply to specific devices and the necessary tools for testing can be challenging in this dynamic environment.

This document aims to guide users in identifying TSI® solutions for testing various respiratory protection and barrier devices against their appropriate standards. Table 1 summarizes device types, relevant standards, and recommended TSI® solutions, along with guidance on accessories and consumables.

Note: Barrier face coverings are distinct from respirators and medical masks.

Image description: The image displays several types of respiratory protection devices, including a white N95-style filtering facepiece respirator, a grey elastomeric respirator with a cartridge, and various disposable masks, some white and some blue.

Table 1: TSI® Filter Testing Solutions and Recommended Accessories

² Designs and appearances may vary within each category. Images are for guidance only.

³ TSI provides guidance, but compliance with standards and regulations is the customer's responsibility. This document is for educational purposes and not a legal reference.

TSI® Solution for Respiratory Filter Testing

The Model 8130A Automated Filter Tester is a globally recognized solution for respirator testing. Its capabilities are also well-suited for barrier face covering testing, as required by ASTM F3502, due to the similarity in testing requirements.

Figure 1 description: The Model 8130A Automated Filter Tester is shown. The left image displays the front view of the unit. The right image presents a schematic of the tester's internal components, illustrating the flow path of aerosols through the system, including the pneumatic cylinder, filter holder, upstream and downstream photometers, aerosol generator, mixing chamber, neutralizer, pressure transducer, flow control valve, and vacuum pump.

The Model 8130A generates a polydisperse NaCl or oil challenge aerosol, detected by two solid-state photometers. These photometers offer excellent sensitivity and dynamic range, enabling measurement of large mass concentrations required for respirator loading tests (see Note A). The 8130A supports flow rates from 10 to 110 L/min and can measure total filtration efficiencies up to 99.9999% during initial penetration and loading tests. Differential pressure can also be measured independently or as part of the filtration test.

Table 2: Available Generator Configurations for the Model 8130A Automated Filter Tester

Various generator configurations are available. Table 2 assists in selecting the appropriate Model 8130A part number for specific testing needs. Refer to Note M for guidance on expanding the capabilities of an existing Model 8130A, such as enabling EN testing.

Detailed Notes on Standards and Testing

Note A: Respirators and Loading

As respirators accumulate particles, their performance changes. A "loading" test is conducted to evaluate performance during significant particle accumulation. Loading tests are required by some, but not all, respiratory protection and barrier device testing standards. Specific loading test parameters are defined by the standard being followed.

Note B: Additional Requirements for Some Devices

• For medical masks: Compliance requires meeting ASTM F2100 and additional US Food and Drug Administration (FDA) requirements. The FDA Guidance Document (Surgical Masks – Premarket Notification [510(k)] Submissions, Section 8) specifies testing with 0.1 µm polystyrene latex spheres (PSL) aerosol, which must be non-neutralized.
• For surgical respirators: In the US, this category must be tested to both the 42 CFR part 84 standard and the ASTM F2100 standard. They are exempt from ASTM F2100's particle filtration efficiency and differential pressure portions if these were covered in the 42 CFR part 84 tests. All other ASTM F2100 requirements must still be met.

Note C: Barrier Face Coverings

ASTM F3502-21, released in February 2021, is the standard for testing barrier face coverings. It specifies performance requirements for particle filtration efficiency and breathability (pressure drop). The particle filtration efficiency test in F3502 is a modified version of 42 CFR part 84 subpart K, using NaCl aerosol for initial efficiency only.

The TSI® Model 8130A meets all technical requirements for testing barrier face coverings under this new standard. European standards are also in development (e.g., CEN CWA 17553, AFNOR SPEC S76-001). Consult the application note on ASTM F3502-21 (Ref. #5) or contact TSI® for more information on barrier face covering testing.

Note D: EN 14683

For medical face masks in the EU, EN 14683 is the relevant standard. It requires a bacterial filtration efficiency (BFE) test and a differential pressure (dP) test (Annex C), but not a particulate filtration efficiency (PFE) test. TSI® does not offer solutions for BFE testing. Contact TSI® to discuss performing the EN 14683 dP test on the Model 8130A.

Note E: EN 13274-7

The filter penetration test has been removed from EN 149:2001+A1:2009 and the draft revision of EN143:2000/A1:2006. It is now referenced by EN 13274-7:2019: “Respiratory Protective Devices – Methods of Test – Part 7: Determination of Particle Filter Penetration.” Refer to the TSI® application note "Testing to EN13274-7:2019 with 8130A-EN” (Ref. #1).

Note F: Scope of Guidance Relative to 42 CFR Part 84

TSI® provides the Model 8130A automated filter tester for filter efficiency and pressure drop measurements of respirators. Other measurements required by 42 CFR part 84 are outside the scope of TSI's solutions. 42 CFR part 84 details testing methods for various respirator designs. Users are responsible for understanding the standard's requirements, including aerosol composition and tester settings.

Note G: ASTM F2100 is Currently Under Review

ASTM F2100 is a parent method referencing other procedures, including ASTM F2299 for filtration efficiency using monodisperse polystyrene latex spheres (PSL). A proposed revision may replace F2299 with the method detailed in ASTM F3502.

Regardless of ASTM F2100 revisions, the US FDA has final authority on testing medical masks and surgical respirators. FDA requirements may differ from subsequent ASTM F2100 revisions.

Note H: 8130A vs. 8130A-EN

These models differ in aerosol generator and minor hardware. Key differences relevant to standards include:

• 42 CFR 84 and GB2626: The 8130A is fully compliant.
• ASTM F3502: The 8130A includes the necessary aerosol generator (PN 8118A; see Note L) for ASTM F3502-21 testing.
• EN 13274-7: The Model 8130A-EN can test to EN 13274-7 (referenced by EN 149) using oil aerosol; see Ref. #1.

Refer to Table 2 for testers compliant with both 42 CFR part 84 and EN 13274-7 upon delivery. Note M provides guidance on expanding existing tester capabilities.

Note I: Data Capture Methods for 8130A

Four data capture methods are available for the 8130A. Choose the most suitable:

• Serial printer: available from TSI®.
• Serial data logger: requires a standard serial cable (third-party purchase).
• Modbus TCP (setup and penetration tests only): available from TSI®.
• HTTP streaming (raw data dump only): contact TSI® for details.

Note J: Custom Filter Holders

The standard 8130A filter holder is for flat sheet media (100 cm²). Custom holders or adapters may be needed for specific device types, such as cartridges or small chambers for respirators. The end user is responsible for designing and sourcing these.

Note K: Network Monitoring of the 8130A

SpiderControl™ is third-party software allowing remote viewing of the 8130A front panel via a networked computer. Touchscreen functions are accessible, but physical buttons for chuck operation are not. This requires a regular Ethernet cable and a host computer, connected directly or via a network.

Note L: Individual Aerosol Generators

Aerosol generators listed in Table 2 can also be purchased individually. This is useful for converting an 8130A to an 8130A-EN (see Note M and Note H). Part numbers for individual generators are in Table 3.

Table 3: Part Numbers for Individual Aerosol Generators

*ASTM F3502 requires salt aerosol; the 8118A is the only generator suitable for this testing.

Note M: Expanding Tester Capabilities

To expand a current tester's capabilities:

• To enable EN-compliant testing on an 8130A: Order relevant EN aerosol generator(s) (Note L) and a conversion kit (PN 8130A-P1233) containing EN-specific pressure gauge and rotameter for hardware modifications. Ensure familiarity with EN standards and required aerosol compositions.
• To enable ASTM F3502 testing on an 8130A-EN: Order the salt generator PN 8118A (see Note L).
• To enable 42 CFR part 84 testing on an 8130A-EN: Order relevant aerosol generator(s) (Note L). Ensure familiarity with 42 CFR part 84 standards and required aerosol compositions.

References

• 1. "Testing to EN13274-7:2019 with 8130A-EN”. TSI® application note AFT-006, A4 and US.
• 2. "42 CFR part 84 Standard.” TSI® application note AFT-001, US.
• 3. "42 CFR part 84 Testing Modes.” TSI® application note AFT-002, US.
• 4. 42 CFR part 84: Approval of respiratory protective devices. Link
• 5. "TSI Tools for Measuring Submicron Particle Filtration of Barrier Face Coverings to ASTM F3502”. TSI® application note AFT-008, A4 and US.
• 6. ASTM F3502: Standard specification for barrier face coverings. Link
• 7. "TSI Tools for Measuring Submicron Particle Filtration of Medical Masks and Respirators to ASTM F2100". TSI® application note AFT-007, A4 and US.
• 8. ASTM F2100: Standard specification for performance of materials used in medical face masks. Link
• 9. CertiTest® Automated Filter Tester Model 8130A specification sheet. A4 and US.
• 10. Model 8130A Automated Filter Tester, description of Field Service Agreement.
• 11. "Determination of Particulate Filter Efficiency Level for N95 Series Filters Against Solid Particulates for Non-Powered, Air-Purifying Respirators” Link

Contact Information

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Application Note AFT-009 Rev. A-(A4) ©2021 TSI Incorporated. Printed in U.S.A.