Toddler Heru Cardi... 100% combed cotton interlock, OEKO-Tex Standard 100 certified fabric snap front for easy on/off ? What is OEKO-TEX? OEKO-TEX Standard 100 certified means that our fabrics have been tested and are free of over 300 chemicals and known irritants. It's a higher standard that is better for skin, better for the environment, and better for parents' peace of mind.