The ZDHC Leather Wastewater Guidelines are a list of conventional and Manufacturing Restricted Substances List parameters, and their limits specific to wastewater discharged from leather manufacturing processes The ZDHC Foundation, which is working to reduce the textile and clothing industry's chemical footprint, has expanded the scope of its wastewater guidelines to include leather. The ZDHC Leather Wastewater Guidelines Addendum has been created as an addition to the current ZDHC Wastewater Guidelines Version 1.1. They set a single unified expectation for sampling, testing and reporting of industrial wastewater and sludge resulting from leather processing. They were developed in collaboration with a wide range of stakeholders from the leather industry including manufacturers, brands, chemical suppliers, and laboratories, ZDHC says.