Purity testing on plant raw material and preparations obtained therefrom In the last twenty years the standards for plant raw material concerning their quality is rising continously. This concerns not only the content of the ingredients lie. active ingredients or groups of substances and the so called leading substances) but also the so called unusual impuritys. The following article specially deals with pesticide residues, heavy metalls, aflatoxines and microbial contamination to show how much work it is from buying, processing and selling the raw material to produce the final product. Furthermore it is explained which steps, controls and documents are required for cultivating a plant to guarantee a high quality of raw material. Options to improve or taking influence on the quality are shown.