EN 14683:2019 Medical face masks. Requirements and test methods
This European Standard specifies construction, design, performance requirements and test methods for medical face masks intended to limit the transmission of infective agents from staff to patients during surgical procedures and other medical settings with similar requirements.
A medical face mask with an appropriate microbial barrier can also be effective in reducing the emission of infective agents from the nose and mouth of an asymptomatic carrier or a patient with clinical symptoms. This European Standard is not applicable to masks intended exclusively for the personal protection of staff.
Bacterial & Viral Filtration Efficiency (BFE/VFE)
The Bacterial Filtration Efficiency (BFE) test is performed on filtration materials and devices that are designed to provide protection against biological aerosols, such as face masks, surgical gowns, caps, and air filters. This test is used for FDA 510(k) submissions for surgical masks, is required by EN 14683, and complies with EN14683.
EN 14683:2019 MEDICAL FACE MASKS – REQUIREMENTS AND TEST METHODS
|EN 14683:2019 Barrier Levels|
|Barrier Testing||Type I||Type II||Type III|
ASTM F2101, EN 14683
Synthetic Blood ASTM
|Not required||Pass at ≥ 16.0 kPa (>120 mmHg)|
|<40 Pa/cm2||<60 Pa/cm2|
16 CFR Part 1610
|See European Medical Directive (2007/47/EC, MDD 93/42/EEC)|
|Complete an evaluation according to ISO 10993|
Bacterial Filtration Efficiency (BFE)
The Bacterial Filtration Efficiency test determines the filtration efficiency by comparing the bacterial control counts to test article effluent counts. The test is conducted using Staphylococcus aureus as the challenge organism. After the filtration media is preconditioned, a liquid suspension of S. aureus is aerosolized and delivered to the filtration media at a constant flow rate of 28.3 liters per minute (LPM) or 1 cubic foot per minute (CFM).
The aerosol droplets are drawn through a six-stage Andersen sampler for collection. The number of bacterial aerosol droplets contacting the filter media is determined by conducting challenge controls without filter medium in the test system. Challenge controls are maintained at 1700 – 3000 colony-forming units (CFU) with a mean particle size (MPS) of 3.0 ± 0.3 µm. This allows filtration efficiencies to be reported up to >99.9%.
The BFE test offers a number of advantages over other filtration efficiency tests. It has been used with little or no modification for years and provides a standard reference for comparison of filtration materials. The mean particle size can be tightly controlled and is sized using a six-stage viable-particle Andersen sampler, permitting stage-by-stage analysis. The BFE procedure is reproducible, and provides a more severe challenge to most filtration devices than would be expected in normal use. Large numbers of material can be evaluated in a relatively short time.
BFE testing is commonly performed along with the Differential Pressure (Delta P) test.
For housed filters, we recommend the Increased Challenge method. This procedure uses a higher concentration of challenge to be delivered to each test material. Filtration efficiency measurements can be determined up to >99.9999%.
Viral Filtration Efficiency (VFE)
The Viral Filtration Efficiency (VFE) test follows the same procedure as BFE, except the challenge organism used is the bacteriophase phiX174.
Challenge controls are maintained at 1100-3300 plaque-forming units (PFU) with a mean particle size (MPS) of 3.0 ± 0.3 µm. This allows filtration efficiencies to be reported up to >99.9%.