Bacteria Penetration Test: Microbial Strikethrough Testing for Textiles
The Bacteria Penetration Test determines the ability of a fabric to prevent the penetration of bacterial, fungal, and viral microorganisms — providing manufacturers of protective and medical textiles with independently validated data to support barrier performance claims.
Scope of the Bacteria Penetration Test

This test evaluates the effectiveness of textile materials as a physical barrier against the penetration of microorganisms — including bacteria, fungi, and viruses — under controlled airflow conditions. It is particularly relevant for manufacturers of medical textiles, protective garments, surgical drapes, and any textile product claiming microbial barrier performance.
Products That Can Be Tested
- Medical and surgical textiles
- Protective garments and gowns
- Nonwoven barrier fabrics
- Healthcare textiles and drapes
- Any textile product claiming microbial penetration resistance
How the Bacteria Penetration Test Works
- Sample Placement: The test sample is placed into the upper section of an impaction apparatus connected to a pump. A collecting vessel containing a diluting buffer is attached to the inner section of the unit.
- Inoculation: The samples are clamped to the upper section of the apparatus and a 100 µl inoculum of the microorganism of interest is distributed in small droplets across the surface of the test material.
- Airflow Application: The pump is switched on to apply airflow through the test material. Any microorganisms that pass through are impacted into a sterile collection buffer in the lower vessel.
- Sample Collection: Following a period of airflow at a specified rate and time, the pump is stopped and the collecting buffer is removed for analysis.
- Enumeration: The collecting buffer is serially diluted and plated on appropriate agar for enumeration of colony forming units (CFUs). For viral penetration testing, TCID₅₀ counts are performed to determine the level of viral penetration through the material.
Third-Party Validation
On passing this test, the product can be labelled as tested by Airmid Healthgroup in support of any claim relating to the test and data received — providing independent, third-party validated evidence of microbial barrier performance.
Turnaround Time
4 Weeks
From receipt of sample
Accreditation
ISO 17025
GLP-compliant, independently audited laboratory
Request a Quote for Bacteria Penetration Testing
Contact Airmid Healthgroup to discuss your microbial barrier testing requirements and receive a tailored quote.
Frequently Asked Questions
What is microbial strikethrough and why does it matter?
Microbial strikethrough refers to the passage of microorganisms — bacteria, viruses, or fungi — through a textile material. For medical, surgical, and protective textiles, preventing microbial penetration is critical to patient and healthcare worker safety. The Bacteria Penetration Test quantifies how effectively a fabric prevents this strikethrough under simulated use conditions.
Can viral penetration be assessed as well as bacterial?
Yes. For viral penetration testing, TCID₅₀ (Median Tissue Culture Infectious Dose) counts are performed on the collected buffer to determine the level of viral passage through the fabric — making this test applicable to both bacterial and viral barrier claims.
What microorganisms can be used in the test?
The test can be conducted using a range of bacteria, fungi, and viruses depending on the product’s intended application and claims. Contact Airmid’s team to discuss which microorganisms are most relevant for your specific product and target market.
What types of textiles can be tested?
Any textile product claiming microbial barrier performance can be assessed — including medical gowns and drapes, surgical textiles, nonwoven protective fabrics, healthcare textiles, and any other material where prevention of microbial penetration is a performance requirement.
What will I receive after bacteria penetration testing?
You will receive a full test report detailing the methodology, airflow conditions, microbial enumeration or TCID₅₀ data, and conclusions — ready to support microbial barrier claims in marketing materials, regulatory submissions, and certification applications.
Related Tests
- ISO 13125:2013 — Antifungal Activity of Photocatalytic Materials
- ISO 16212:2011 — Yeast and Mould Enumeration in Cosmetics
- ISO 27447:2019 — Ceramic Antimicrobial Surface Validation
- BS ISO 16869:2008
- BS EN 1040:2005
- BS EN 1275:2005 — Fungicidal or Yeasticidal Activity
- BS EN 1276:2009 — Bactericidal Activity of Chemical Disinfectants
- BS EN 1650:2008
- BS EN 1884:1999 — Feather and Down Bacterial Analysis
- BS EN 13610:2002 — Virucidal Claim Verification
- BS EN 13697:2015
- BS EN 13704:2018
- BS EN 13727:2003
- ASTM E2149-10
- ISO 13629-2:2014
- ASTM G21 — Resistance of Synthetic Polymeric Materials to Fungi
- JIS Z 2801 — Antimicrobial Activity of Plastics
- AATCC 100 — Fabric Testing and Claim Verification
- AATCC 174 — Antimicrobial Activity Assessment of New Carpets



