Overview
ISO/TS 20660:2019 - Nanotechnologies: Antibacterial silver nanoparticles provides guidance for specifying the physicochemical characteristics and recommended measurement methods for silver nanoparticles (AgNPs) in powder or colloidal forms intended for antibacterial applications. The technical specification helps producers supply standardized characterization data to buyers and testing laboratories. It does not cover health and safety considerations during manufacture or use.
Key topics and requirements
- Essential vs additional characteristics: The specification separates characteristics producers shall measure (Table 1) and those they should measure (Table 2). Results must be reported in the units indicated in the standard.
- Core measured parameters:
- Average size and size distribution of primary particles - measured by SEM or TEM (image-based equivalent diameters; ISO 16700, ISO 10797).
- Zeta potential - electrophoretic measurement; report pH and ionic conditions (ISO 13099-2).
- Specific surface area - gas adsorption, BET method (ISO 9277; ISO 18757 for material-specific guidance).
- Total silver content - elemental analysis techniques (ICP-MS/ICP-OES/AAS; ISO 17294 series, ISO 11885, ISO 26845).
- Additional recommended measurements:
- Hydrodynamic size (DLS, PTA - ISO 22412, ISO 19430).
- Silver nanoparticle number concentration (spICP-MS, PTA, SAXS - ISO/TS 19590 and referenced methods).
- Metrology and comparability: The document stresses that some properties are method‑defined; results from different techniques may not be directly comparable. Powder samples often need dispersion before analysis; colloids can be measured directly.
- Supporting material: Annex A (measurement methods), Annex B (relationship between characteristics and antibacterial performance), Annex C (antibacterial performance test) guide implementation and interpretation.
Practical applications and users
Who benefits from ISO/TS 20660:2019:
- Manufacturers and suppliers of antibacterial silver nanoparticles - to provide consistent product specifications to customers.
- Quality control and analytical laboratories - to select and report appropriate characterization methods.
- Product developers and formulators - to correlate AgNP physicochemical traits with antibacterial performance.
- Purchasers and specification writers - to compare batches and suppliers based on standardized tests.
- Regulatory and conformity assessment teams - for harmonized reporting (note: the standard does not replace health/safety regulatory requirements).
Practical uses:
- Creating product datasheets with validated AgNP characteristics.
- Designing acceptance criteria for incoming nanoparticle batches.
- Supporting performance claims by linking measured properties (size, surface area, ion content) to antibacterial behavior (see Annex B).
Related standards
Referenced normative documents include ISO 26824, ISO/TS 80004-1/2 and measurement standards such as ISO 16700, ISO 10797, ISO 13099-2, ISO 9277, ISO 17294, ISO 22412, ISO/TS 19590, among others. These provide method details and terminology for AgNP characterization.