The Oeko-Tex Standard 100 is a globally uniform testing and certification system for textile raw materials, intermediate and end products at all stages of production. The test for harmful substances comprise substances which are prohibited or regulated by law, chemicals which are known to be harmful to health, and parameters which are included as a precautionary measure to safeguard health. Manufacturers are entitled to mark successfully tested products or article groups with the Oeko-Tex label. A certificate which is issued, applies for one year and can be renewed as often as required.