Toxicity, also known as biological harmfulness, generally refers to the relative ability of exogenous chemicals to cause direct or indirect damage when they contact or enter the living organism. Toxicity is closely related to the physical and chemical properties of the substance itself, as well as the dose, the way of contact and the time of contact. When assessing the risk of specific compounds in microspectrum medicine, the toxicity data of target compounds, such as NOEL, LOEL, LD50, etc., are determined by searching Toxline of the National Library of Medicine of the United States or SIDS of OECD of the European Union. For compounds without toxicity data, appropriate toxicity tests can be selected, NOEL and PDE can be calculated according to toxicity test results, and the limit can be calculated according to the maximum daily dosage of corresponding preparations. In summary, we combine the requirements of ICH, 1) to predict genotoxicity by software that conforms to the guidelines of ICHM7; 2) to retrieve existing databases of genotoxicity impurities; 3) to set reasonable limits based on relevant data.