What does the certificate state? The certification system ECO PASSPORT is designed for manufacturers of process chemicals and chemical compounds. The leather and textile chemicals certified in accordance with the ECO PASSPORT have been tested for harmful substances in critical concentrations as listed in the ECO PASSPORT standard. The label also gives transparent proof of which articles meet the criteria for ecologically responsible textile and leather manufacture. Once per year, OEKO-TEX® updates the banned substances and limit values and expands them to include new scientific findings or statutory requirements.