Clothing dyes have a huge impact on the environment, especially around the factories that produce clothing. They discharge a toxin called nonylphenol, which is deadly to aquatic life. However, nonylphenol doesn’t just affect the water. It stays in clothing until it is washed multiple times. While the EU has banned imports containing clothing with nonylphenol, the US has not.
Dyeing clothes also uses enormous amounts of fresh water, more than half a trillion gallons of water all together. The dye water is discharged (often untreated) into nearby rivers, which feeds into the sea, eventually making its way worldwide.
An example of clothing dye affecting the environment is the Citarum River, the largest and longest river in West Java, Indonesia. It is considered one of the most polluted rivers in the world, partially due to the textile factories in Indonesia. When the textile boom began in Indonesia, there was not much monitoring of its infrastructure, and so clothing manufacturers would just dump their chemicals into the river. This turned Citarum into nothing but an open sewer containing lead, mercury, arsenic, and many other toxic chemicals. This affected aquatic life and human life.
There is a new type of waterless dye, but it has not been deployed at most manufacturing facilities. Facilities may also be reluctant to adopt it because it is expensive to install and only works on certain fabrics.