Summary
Researchers from the Norwegian University of Science and Technology (NTNU) and SINTEF tracked a 110-gram pure white cotton T-shirt through its full chain—from production in Bangladesh to use in Norway, sorting in Lithuania, regeneration in India, and finally back to spinning in Bangladesh—and found that 44% of the raw cotton was discarded during spinning, dyeing, and cutting, never becoming clothing; under current conditions, the upper limit for recycling old clothes into new cotton is only 17%.

Key points

  • A white T-shirt requires 197 grams of raw cotton, while the final product weighs only 110 grams; 86 grams of cotton are lost in production, with the largest loss occurring at the spinning and carding stage (49 grams).
  • About 60% of Norway's waste textiles go directly into mixed household waste for incineration; of the 40% collected separately, only 1% to 3% remains in the country, with the rest exported.
  • Under a scenario of recycling factory waste, the fiber recovery rate could rise to 44%; if only the collection rate is raised from 40% to 90%, the recovery rate would still reach only 37%, with climate impact improving by only about 2%.

A research team from the Norwegian University of Science and Technology (NTNU) and SINTEF published a paper in the Journal of Circular Economy, using a size M, 110-gram, plain white cotton T-shirt with no print or trims as a sample to simulate its complete material flow from "birth" to "regeneration." Production was set in Bangladesh; after being shipped to Norway, it was worn 30 times and washed once every two wears, then discarded.

Following the real trade route, old clothes collected in Norway are first pre-sorted, then transported by truck and ferry to a sorting plant in Vilnius, Lithuania; the portion deemed recyclable is then shipped to a mechanical recycling plant in Panipat, India, and finally to a yarn factory in Bangladesh. The research team combined this logistics map with a life cycle assessment covering climate, freshwater pollution, water resources, and land use.

The data show that the first T-shirt's carbon emissions are about 3.5 kilograms of CO2 equivalent, with dyeing and finishing the largest single contributing stage. Making one shirt requires 197 grams of raw cotton, while the finished product is only 110 grams. The most consumption-intensive stage is the spinning mill: during carding, short fibers and impurities are removed, and about 49 grams of cotton are lost there. The dyeing factory loses about 17 grams, partly due to uneven dyeing and partly due to failed inspection; the sewing workshop's cutting scraps discard roughly the same amount again; the knitting stage loses very little, about 3 grams. In total, 86 grams of cotton that had already been grown, ginned, and delivered to the factory never became clothing.

This 44% production loss rate is far higher than the widely cited 12% in the Ellen MacArthur Foundation's 2017 report. The Norwegian team believes the lower figure comes from national statistics that never went deep inside factories, whereas their data come from recent surveys of factories in Bangladesh. The study also notes that factories overproduce to ensure delivery volumes, and the excess fabric becomes dead stock.

After old clothes enter Norwegian wardrobes, losses continue. About 60% of Norway's waste textiles go directly into household waste for incineration to generate energy; of the 40% collected separately by charities and recyclers, only 1% to 3% remains in the country, with the rest mainly exported to Eastern Europe for sorting and then flowing onward in ways that are difficult to track.

In the model, the sorting stage removes a small number of shirts, and shredding destroys about one-fifth of the remainder—mechanical recycling makes cotton fibers shorter and shorter. The 33 grams of cotton ultimately recovered must be blended with fresh cotton at a ratio of about 1:5 to spin a second shirt. The authors point out that a pure cotton T-shirt is already one of the easiest garments to recycle; items with zippers, prints, or polyester blends perform even worse.

The study also simulated policy scenarios. The EU Waste Framework Directive has required member states to collect textiles separately since January 2025, and Norway is also subject to it; under the baseline scenario, 40% of discarded shirts are collected. If only the collection rate is raised to 90%, the fiber recovery rate could rise to 37%, but the climate impact would improve by only about 2%. By contrast, if waste is cut at the factory end and reduced to the loss levels already achieved by some factories in Bangladesh, the model requires 23% less raw cotton, climate impact falls by about 10%, and water, land, and freshwater pollution indicators drop by 20% to 25%. In another scenario, recycling factory waste could raise the fiber recovery rate to 44%.

Johan Berg Pettersen, associate professor in NTNU's Industrial Ecology Programme and corresponding author, said that improving production efficiency can bring significant environmental benefits. Kristina Mæskes, senior researcher at SINTEF and co-author, noted that downstream measures cannot meet the EU's recycling targets, and that if the EU wants more recycled textiles, "countries must shift their efforts upstream in the value chain." The EU's Ecodesign for Sustainable Products Regulation requires textiles sold in Europe to be highly recyclable by 2030, but it currently does not address factory waste.

The authors acknowledge that 17% is an upper bound: in the model, all old clothes that pass sorting go directly to shredding, whereas in reality a considerable share is first resold or repaired and never reaches recyclers at all. The model also assumes 1:1 substitution of recycled cotton for new cotton, but mechanically recycled fibers are shorter and weaker, and today's spinning mills can tolerate at most about 30% recycled fiber in the blend. In addition, garment factories in Bangladesh currently have no legal obligation to sort or recycle cutting waste, and large amounts of waste circulate through informal markets that no one tracks. A 2024 report hosted by UNICEF for the Business & Human Rights Resource Centre found child labor in this informal recycling industry.

Sensitivity tests show that depending on the loss rate used, one shirt requires 158 to 265 grams of raw cotton, and production waste is always the largest single leakage point in the system. Fast-fashion jeans carry a heavy footprint because of their short lifespan, but the Norwegian team reached a different conclusion: for a pure white shirt, the biggest leak is in the factories of Bangladesh, long before anyone has a chance to donate it or wear it out—and Europe's textile policy has so far not looked there.

Source: Researchers followed one cotton T-shirt around the world and found most of it never became clothing - AOL · Originally published on 2026-10-04