VFE Viral Filtration Efficiency Test

VFE Virus Filtration Efficiency Test

The VFE test procedure is adapted from Military Standard MIL-M-36954C and ASTM F2101. test aerosol is Bacteriophage OX174. Bacteriophage is one of the smallest viral organisms. It has a diameter of 0.025-0.027 microns. The test is very similar to the BFE test, except for the use of a smaller organism. The VFE procedure has recently attracted attention due to avian flu and concerns with coronavirus.

VFE Test

It is harmonized in accordance with the following test method, harmonized with the Standard Test Method to Assess the Bacterial Filtration Efficiency (BFE) of Medical Facial Mask Materials Using Staphylococcus aureus's Biological Aerosol. This test is generally required to measure product performance or for FDA certification.

Viral Filtration Efficiency (VFE)

The Viral Filtration Efficiency (VFE) test follows the same procedure as BFE, except that the used organism of difficulty is bacteriophase phiX174.

Difficulty controls are maintained in 3.0-0.3 plaque-forming units (PFU) with an average particle size (MPS) of 1100 ± 3300 µm. This allows filtration efficiencies to be reported up to> 99,9%.

VFE testing is done to determine filtration efficiency by comparing viral control numbers with test substance waste numbers. A bacteriophage X 174 suspension was aerosolized using a nebulizer and fed to the test product at a constant flow rate. The aerosol droplets were drawn from the Andersen sampler, a six-stage live particle for collection. This method allows the transmission of test items to a repeatable difficulty. The VFE test procedure is adapted from ASTM F2101.

The entire test method for the Viral Filrration Effect is based on the following acceptance criteria.

VFE is not recognized as a standard test method, but has been adapted from the ASTM F2101 method by the EUROLAB Laboratory. This method was included in the test run because it is sometimes used by manufacturers in marketing literature and in FDA 95 applications and European standards for N510 FFRs with an antimicrobial / antiviral agent. Penetration is measured using bacteriophage phiX174 as the parent virus and Escherichia coli bacteria as the host. A suspension of phiX174 is aerosolized in a nebulizer and each test is performed with a difficulty level of 2-3.0 plaque forming units (PFU) with an MPS of 0.3 ± 1700 µm for 2700 minutes. A virus aerosol is not a single virus particle, but a virus-containing water droplet. MPS was calculated as shown for the BFE method. The un-neutralized aerosol sample was drawn through a test sample clamped on the top of the 6-step Andersen sampler with E. coli inoculated agar plates for collection. Flow rate was kept at 28.3 L / min. PFUs represent the number of viral aerosol particles or droplets. The total number of viral aerosols for test samples and positive controls without test sample are obtained as described for the BFE method. A virus-free negative control is performed in the airflow to determine the background challenge in the glass aerosol chamber prior to testing. Filtration efficiency is calculated using PFU similar to the method described for BFE. Similar to BFE, VFE results range from 1 to 99.9% as there are low (<1) and high (> 99.9) detection limits based on the test parameters used and how the calculations are made.

EUROLAB VFE Main Test Method

VFE testing is performed to determine the filtration efficiency of test products by comparing viral control numbers upstream with the downstream numbers of test products. A bacteriophage suspension (PX174 was aerosolized using a nebulizer and forced delivery to the test product at a constant flow rate and constant air pressure, kept in forced-forming, average particle size 1.1 - 3.3 x 10 ^ plaque forming units (PFU), aerosol droplets, six for collection It is drawn from the EUROLAB sampler, which is a progressive live particle. The VFE test procedure is adapted from ASTM F2101 and gives results to its customers in a verified method.

Tests are conducted in accordance with US FDA and European standards good manufacturing practices (GMP) regulations 21 CFR Parts 210, 211 and 820, meeting all test method acceptance criteria.

As EUROLAB Laboratory, we provide VFE testing services. These tests are carried out in masks, overalls, gowns and all processed fabrics.