A Comprehensive Introduction to Water Footprints

Production chaincottonCotton seedHulling/extraction0.160.470.510.33Cotton seed oilCotton seedcake1.071.00Cotton seed oil,refinedCotton plantHarvestingSeed-cotton0.630.18Ginning0.100.20Cotton linters0.350.820.050.10Garnetted stockCotton lint1.001.00Cotton, notcarded or combedCarding/Spinning0.950.99Cotton, carded orcombed (yarn)0.950.99Knitting/weaving0.050.10Grey fabricYarn wasteWet processingLegend0.350.82Product fractionValue fraction1.001.00FabricFinishing1.001.00Final textileA cotton shirt is made from cotton fabric, which is made from combed or cardedcotton, which is derived from cotton lint, which comes from seed cotton, which isharvested from the cotton field. Indeed, before the final cotton textile reaches tothe hands of a consumer it passes through a number of intermediate processes andproducts. First the seed cotton is processed into lint (we get only 350 kg of lintout of 1000 kg of seed cotton), then after carding, spinning and weaving we getgrey fabric (1000 kg of lint produces only 900 kg of grey fabric), then it goes tothe wet processing (bleaching and dying) and finishes as final printed cottontextile. It requires about 30 m3 per ton for bleaching, 140 m3 per ton for dyingand 190 m3 per ton for printing. The average water footprint of printed cotton(for example a pair of jeans weighing 1 kilogram) is 11000 litres per kilogram.12