Unno is a chemical safety label. UNNO is the United Nations dangerous goods number and the abbreviation of dangerous goods recommended by the United Nations Committee of Experts on the Transport of Dangerous Goods. The quantity of dangerous goods in China is CNNO.

According to the national standard "Chemical Safety Labels", the safety label uses a combination of words, graphic symbols and codes to indicate the dangers and safety precautions of chemicals.

Safety labels are pasted, hung and sprayed on packages or containers by production enterprises before the goods leave the factory. If the package is replaced, it will be re-pasted, hung and sprayed by the replacement unit.

Labels of containers or packages containing dangerous chemicals can only be removed after treatment and complete elimination of their dangers.