An analytical toolbox to verify the presence, quantity and origin of recycled cotton fibres in textile garments

The textile industry is one of the most polluting industries. To reduce its environmental impact, the entire supply chain must transition from a linear to a circular economy, making textile recycling at end-of-life critical. Stimulated by new regulations, the industry is increasingly incorporating recycled – mainly mechanically – cotton fibres into new garments. However, producing garments with recycled fibres is costlier than using virgin fibres. Currently, there is no independent way to assess the quantity of mechanically recycled cotton claimed by producers. As a result, “greenwashing” is frequently encountered. In this study, an analytical toolbox was developed to enable independent verification of the claimed mechanically recycled cotton content in garments. For the toolbox three analysis methods were developed. Microscopy can be used to qualitatively confirm the presence of mechanically recycled cotton fibres. Measuring the fibre length distribution allows the amount of recycled fibres to be determined semi-quantitatively. Degree of polymerisation (DP) measurements can be used to distinguish the pre- and/or post-consumer origin of the recycled fibres. Once further enriched and developed into a standard, the toolbox will be an asset in reducing greenwashing and boosting the use of recycled fibres.