Quantification and evaluation of chemical footprint of woollen textiles

The chemical pollutants discharged in the production processes of textile products cause severe impact on the environment. The chemical footprint (ChF) methodology provides a new way to quantify the toxicity impacts caused by chemical pollutants. ChF does well in identifying priority chemical pollutants and helping enterprises to select greener chemicals to reduce the environment impacts. In this study, the ChF of woollen yarn were assessed with the data that collected from the production processes. The results showed that the ChF of dyeing process (4.10E+06 l) accounted for the largest proportion, because a large number of auxiliaries were used in the dyeing process to prevent uneven dyeing and colour difference, followed by scouring (7.79E+05 l) and finishing (8.11E+03 l). Among all the discharged chemical pollutants, polyoxyethylene nonyl phenyl ether (1.37E+06 l) caused the most ecotoxicity severe impact on the environment due to its high bioaccumulation and high toxicity to ecosystem, followed by sulfuric acid (1.03E+06 l). Sodium chloride and hydrogen peroxide were the two substances that caused the least environmental load. The overall uncertainty caused by toxicity prediction data accounting for 20.2% of the total ChF, and the uncertainty of the scouring process was the most. The results are referable for wool textiles producers to enhance the textile chemicals management.