As an accredited test laboratory with over 1.000 staff worldwide, Hohenstein belongs to one of 18 institutes run by the OEKO-Tex® company and specialises in testing for toxic substances in textile products and textile components. Established two years ago, the ECO PASSPORT by OEKO-TEX® certification serves to examine textile chemicals used as aids in production. The article details the certification process using the example of Total’s Lissolfix coning oil.