BS EN ISO 20743:2021: Antibacterial Activity Testing of Textile Products
The BS EN ISO 20743:2021 standard outlines a test method to determine the antibacterial activity of textile products incorporating an antibacterial finish to prevent or mitigate the growth of bacteria. It applies to cloth, clothing materials, bedding, home furnishings, and nonwovens.

Scope of BS EN ISO 20743:2021
ISO 20743:2021 (formerly BS EN ISO 20743:2013) is an internationally recognised standard for evaluating the antibacterial efficacy of textile products treated with antibacterial finishes. It covers a wide range of textile applications — from clothing and bedding through to home furnishings and nonwoven materials.
How the BS EN ISO 20743:2021 Test Works
- Inoculation: Bacteria (Staphylococcus aureus or Klebsiella pneumoniae) are inoculated onto both treated (test) and untreated (control) fabric samples. Other bacterial strains can be requested depending on the product’s intended application.
- Incubation: Samples are incubated for a set duration — typically 18 to 24 hours — under controlled conditions to allow bacterial growth on the untreated control.
- Enumeration: After incubation, viable bacteria are extracted from both the test and control fabrics and enumerated using standard microbiological methods.
- Antibacterial Activity Calculation: The antibacterial activity of the textile product is calculated according to the criteria defined in the standard — expressed as a log reduction in viable bacteria on the treated fabric compared to the untreated control.
Sample Submission & Turnaround
Turnaround Time
4 Weeks
From receipt of samples
Quote
Custom
Based on number of samples and bacterial strains
We will provide a quote based on the number of samples and the number of bacterial strains you wish to test. Contact us to discuss your requirements and get started.
Third-Party Validation
On passing this test, the product can be labelled as having been tested by Airmid Healthgroup to BS EN ISO 20743:2021 (formerly BS EN ISO 20743:2013) — supporting any claim relating to the test and data received. Independent third-party validation strengthens consumer confidence and supports regulatory and marketing submissions globally.
Request a Quote for BS EN ISO 20743:2021 Testing
Contact Airmid Healthgroup to discuss your antibacterial textile testing requirements and receive a tailored quote.
Frequently Asked Questions
What is BS EN ISO 20743:2021 and what does it measure?
BS EN ISO 20743:2021 is an international standard that specifies the method for testing the antibacterial activity of textile products with antibacterial finishes. It measures the reduction in viable bacteria on a treated fabric compared to an untreated control after a defined incubation period — providing a quantified log reduction value to support antibacterial product claims.
What is the difference between BS EN ISO 20743:2021 and AATCC 100?
Both standards evaluate the antibacterial activity of treated textiles but use slightly different methodologies and are recognised in different markets. ISO 20743:2021 is the internationally recognised standard used widely in Europe and Asia. AATCC 100 is more commonly referenced in the US market. Airmid can advise which standard — or combination of standards — is most appropriate for your product and target markets.
Can bacteria other than Staphylococcus aureus and Klebsiella pneumoniae be used?
Yes. While the standard specifies Staphylococcus aureus and Klebsiella pneumoniae as the primary test organisms, Airmid can accommodate testing against other bacterial strains upon request — particularly where the manufacturer needs data relevant to a specific intended application such as healthcare or sportswear.
What textile products can be tested to BS EN ISO 20743:2021?
The standard covers a broad range of textile products including clothing fabrics, bedding, home furnishings, nonwovens, and any other textile incorporating an antibacterial finish. If you are unsure whether your product is in scope, contact our team for a quick assessment.
What will I receive after BS EN ISO 20743:2021 testing?
You will receive a full test report detailing the methodology, bacterial enumeration data, calculated antibacterial activity values, and conclusions — along with the right to label your product as independently tested by Airmid Healthgroup to BS EN ISO 20743:2021. This supports antibacterial claims in marketing materials and regulatory submissions.
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