This document establishes a qualitative-quantitative analytical evaluation (i.e. determination) of microplastics to be able to define their:      particle number;      morphology (morphological characteristics);      dimensional distribution;      the type, chemical origin or nature of polymers and their colour, if present. This document is applicable to the determination of microplastics (from the textile sector) collected in various matrices (for example textile process wastewater, clothes washing water, textile process air emissions, textile process solid waste). This document specifies expression of results in terms of estimated surface area and mass of microplastics (MPs) per unit sample. It enables the expression of the results of the quantification of microplastics (MPs) from various sources, including samples related to the production, processing, treatment and use of textiles (raw material, manufacturing process, sample like wastewater from washing clothes, air, and industrial process water). This document applies to textile sector samples of matrices of different physical states (solid, liquid or aeriform), for example:      solid samples from textile production processes;      water samples from the textile production process and/or from the washing of clothing (e.g. garments or other textiles, ISO 4484-1 or ISO 4484-3 can be applied in order to prepare a liquid to be tested);      air samples to test the air quality in the workplace of textile companies. This document, being able to provide information such as size, shape, surface and mass (estimated), enables the transfer of useful information for ecotoxicological assessments to specialists.