The extensive use and discharge of chemicals is one of the main factors leading to serious environmental pollution in the textiles and apparel industry. The chemical footprint (ChF) is a toxicity-based chemical management method that is used to quantitatively evaluate the potential toxic effects of chemical pollutants discharged during the production of textiles and apparel products on human health and environmental safety. Compared with the traditional quantity-based method, this method needs to simulate the entire process of chemicals from discharge to impact, involving a series of steps of fate, exposure and effect, which greatly increases the difficulty of modeling. A scientific question is whether it is worth spending so much effort to quantify the toxicity of chemicals. Taking the warp-dyeing phase of denim jeans as an example, this paper calculated the ChFs for both human and ecological toxicities of textile chemicals based on the USEtox model, and compared them with the values of discharge quantities. The results reveal that there is a certain inconsistency between the discharge quantity and toxicity of chemical substances. Relying solely on the amount of chemicals discharged can sometimes lead to misjudgments, emphasizing the importance of controlling the toxicity of chemicals.