RoHS is a mandatory standard established by the European Union legislation (Restriction of Hazardous Substances). 

The standard has been officially implemented on July 1, 2006, mainly used to regulate the material and process standards of electronic and electrical products, so that it is more conducive to human health and environmental protection. The purpose of the standard is to eliminate lead, mercury, cadmium, hexvalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers in electrical and electronic products (note: the correct Chinese name of PBDE refers to polybrominated diphenyl ethers, polybrominated diphenyl ethers is wrong) a total of 6 substances, and focus on the content of cadmium cannot exceed 0.01%.