Cinnamon products were suspected of being a health hazard because they contain the substance coumarin. The Federal Institute for Risk Assessment has derived a tolerable daily intake level. This amount can be absorbed over one's lifetime without any risk to health. It is 0.1 milligram of kumarin per kilogram of body weight per day. If this value is exceeded for short periods, it poses no danger to health. Coumarin is poorly water soluble. Since Chinese medicine predominantly uses water as an extracting agent, the amount of coumarin in the decoction or granules is rather small. Therefore, there is no risk in taking Chinese medicines. Nevertheless, no high doses of Cassia cinnamon products should be given to small children, pregnant women and patients with imparied liver function.