Overview
ISO 23641:2021 specifies a laboratory method for determining the antibacterial effectiveness of open‑cell flexible cellular polymeric materials (for example, antibacterial‑treated foams used in sponges, mattresses, pillows and upholstery). The procedure is designed so the test inoculum efficiently contacts the internal open‑cell surfaces of flexible foams, enabling reliable measurement of antibacterial activity for intermediate and final products. The document includes test strains, reagents, equipment, sterilization, incubation, viable‑count measurement and reporting requirements.
Key Topics
- Scope and purpose: method for open‑cell flexible cellular polymeric materials to evaluate antibacterial treatment performance.
- Test organisms: both Staphylococcus aureus and Escherichia coli are required test species (specified strains are listed in the standard).
- Antibacterial activity: expressed as the log difference in viable cell counts between treated and untreated material; activity ≥ 2.0 is judged significant.
- Test procedure elements:
- Preparation and sterilization of specimens and apparatus (dry‑heat and high‑pressure steam sterilization are detailed; autoclave condition given as (121 ± 2) °C and (103 ± 5) kPa).
- Media and reagents (nutrient media, PBS‑type buffers, surfactant such as polysorbate 80).
- Incubation and agitation (example shaker settings provided: ~150 ± 10 rpm with ~30 ± 5 mm amplitude).
- Viable cell counting and result expression (pour plate method is included as an annex).
- Equipment guidance: incubator, autoclave, biological safety cabinet, sterilized cups and shaker specifications are described to ensure repeatability.
- Safety note: users should be familiar with microbiology and apply appropriate biosafety practices.
Applications
- Product quality and claims verification: manufacturers of antibacterial‑treated open‑cell foams (kitchen sponges, mattress pads, cushions) can use ISO 23641 to substantiate antibacterial performance.
- Third‑party testing and certification: independent laboratories and test houses can adopt the method for product evaluation and compliance testing.
- R&D and supplier control: materials scientists and quality teams can use the standard during development, production control and supplier acceptance testing.
Who should use this standard
- Foam and polymer manufacturers, product designers, quality assurance teams, microbiology testing laboratories, regulatory compliance officers, and procurement professionals assessing antibacterial claims.
Related standards
- ISO 1923 - Cellular plastics and rubbers - Determination of linear dimensions.
- ISO/IEC Directives - referenced for editorial and procedural context.
Keywords: ISO 23641:2021, antibacterial effectiveness, flexible cellular polymeric materials, open‑cell foam testing, Staphylococcus aureus, Escherichia coli, antibacterial activity, foam antibacterial test.