ROHS is a mandatory standard established by European Union legislation, with its full name being the Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment. This standard officially came into effect on July 1, 2006, primarily aimed at regulating the materials and process standards of electronic and electrical products to better protect human health and the environment. The purpose of the standard is to eliminate six substances—lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (PBDEs)—in electrical and electronic products, with a key stipulation that the lead content must not exceed 0.1%.