Overview
ISO 4484-3:2023 - Textiles and textile products - Microplastics from textile sources - Part 3 specifies a laboratory method to measure the mass of material (including fibre fragments and non-water-soluble debris) released from textile end products during domestic washing. The method collects material discharged from the outlet hose of a standard washing machine (as described in ISO 6330) using a filter bag, transfers the collected material to a membrane filter, and determines mass by gravimetric difference.
Key technical topics and requirements
- Scope and applicability: Applies to finished textile and home textile end products (e.g., fleece garments, shirts, trousers, blankets, curtains) that can be washed in a domestic machine. Not applicable to fabrics/cut textile products.
- Washing machine and program: Uses a standard domestic washing machine specified in ISO 6330; washing conditions follow care labelling per ISO 3758. The machine must meet requirements given in Annex B of ISO 4484-3.
- Collection system: A woven filter bag (aperture (10 ± 4) μm) is attached to the washing machine outlet hose to capture discharged material. Aperture size guidance and construction are in Annex A and Annex I.
- Sample size and repetitions: At least two test specimens per wash; the method is repeated for three sets (3 test runs). Annex G discusses specimen number effects.
- Gravimetric measurement: Collected material is transferred to a polycarbonate membrane filter (~47 mm diameter, 10 μm) (or stainless steel equivalent). Weighing uses a high-resolution analytical balance (0.1 mg resolution); oven drying at (105 ± 3) °C and conditioning per ISO 139 are specified. Mass is calculated by subtracting blank (filter + bottle) mass from loaded assembly.
- Controls and reporting: Includes an empty-wash control to assess machine cleanliness, procedures for multiple wash cycles, repeatability/reproducibility guidance, and detailed reporting requirements (Clause 12). Annexes cover detergent references, interlaboratory trials, and collection percentages.
Practical applications and users
Who uses ISO 4484-3:2023:
- Textile manufacturers and product designers - evaluate and reduce microfiber shedding during laundering.
- Independent testing laboratories and conformity assessment bodies - provide standardized, comparable gravimetric data on material release from finished products.
- Environmental researchers and policymakers - quantify microplastic mass emission from household laundering for exposure and policy studies.
- Brands and sustainability teams - support ecolabel claims, product improvement, and supply‑chain testing.
Benefits:
- Provides a repeatable, ISO‑aligned method for comparative measurements.
- Integrates with care-label guidance (ISO 3758) and domestic washing procedures (ISO 6330) for realistic conditions.
- Enables product development decisions to minimize microfiber release.
Related standards
- ISO 6330 - Domestic washing and drying procedures for textile testing
- ISO 3758 - Care labelling code using symbols
- ISO 139 - Standard atmospheres for conditioning and testing
- ISO 3696 - Water for analytical laboratory use
- ISO 4484-2 - Identification/quantification of components in collected materials
Keywords: ISO 4484-3:2023, microplastics from textile sources, domestic washing method, measurement of collected material mass, filter bag, textile testing, ISO 6330, care labelling ISO 3758, microfiber shedding.