1.1 This test method is used to determine the microbial barrier properties of wound dressing. The test is designed to measure the ability of microorganisms to penetrate through a material (wound dressing) under specific conditions. This qualitative in vitro test will demonstrate results such as “Growth” or “No Growth” of the test organism on the agar surface after a specified contact time.

1.2 The test method includes an initial inoculum of 3.0 × 10⁶ ± 2.0 × 10⁶ CFU/mL and a contact time of 24 h to 72 h or per the wound dressing label claim. To show barrier properties, wound dressing should not allow the challenged organism to penetrate and reach the media surface.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 Testing is to be performed by individuals trained in microbiological techniques under appropriately controlled conditions to ensure the integrity of results and personnel safety.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

1.1 This test method is used to determine the microbial barrier properties of wound dressing. The test is designed to measure the ability of microorganisms to penetrate through a material (wound dressing) under specific conditions. This qualitative in vitro test will demonstrate results such as “Growth” or “No Growth” of the test organism on the agar surface after a specified contact time.

1.2 The test method includes an initial inoculum of 3.0 × 10⁶ ± 2.0 × 10⁶ CFU/mL and a contact time of 24 h to 72 h or per the wound dressing label claim. To show barrier properties, wound dressing should not allow the challenged organism to penetrate and reach the media surface.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 Testing is to be performed by individuals trained in microbiological techniques under appropriately controlled conditions to ensure the integrity of results and personnel safety.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

5.1 An ideal wound dressing absorbs wound exudates, reduces the bioburden within/on the dressing, and protects wounds from microbial penetration through the dressing. Microbial barrier effectiveness testing is performed to measure the ability of microorganisms to penetrate through a material under specific conditions.

5.2 The test may be used for solid wound dressings with or without the addition of antimicrobial agents where the manufacturer is claiming microbial barrier properties in their performance claim. Barriers can be physical (polyurethane) and/or chemical (antimicrobial barrier).

• 5.2.1 Five (5) commonly used solid wound dressings are (1) hydrogel, (2) hydrocolloid, (3) film, (4) foam, and (5) alginate. Liquid adhesives also protect the wound from being infected by microorganisms. Liquid adhesive dressings contain cyanoacrylate or polyacrylate, which polymerizes quickly to create a solid barrier and protect the wound from contamination.

5.3 This qualitative test method can be used to determine the microbial barrier properties of solid wound dressings including liquid adhesive.

• 5.3.1 The test represents an in vitro wound model by using a nutrient-rich medium to mimic the wound, the contact time will represent the maximum period of use for a single dressing application on the wound, and an incubation temperature of 37 °C ± 2 °C represents the human body temperature.

5.4 Results are documented as “Growth” or “No Growth.”

• 5.4.1 No growth underneath the dressing indicates the barrier properties of the wound dressing are effective at preventing microbial penetration through the dressing.
• 5.4.2 Growth underneath the dressing demonstrates that the challenge organism was able to penetrate the dressing and reach the media surface, indicating that microorganisms can reach the wound by penetrating through the dressing from the outside environment.