ROHS stands for 1, the abbreviation of RoHS: restriction of hazard substance, RoHS directive to restrict the use of certain harmful substances in electronic and electrical equipment (hereinafter referred to as RoHS directive) 2. As explained by the first layer 3. RoHS directive restricts the use of the following six hazardous substances 1. Examples of lead (Pb) using this substance: solder, glass and PVC stabilizer 2. Examples of mercury (Hg) using this substance: thermostats, sensors and switches. Light bulb 3. Examples of cadmium (Cd) using this substance: switch, spring, connector, housing and PCB, contact, battery 4. Examples of hexavalent chromium (Cr6) using this substance: metal corrosion coating 5. Examples of PBBs using this substance: flame retardants, polychlorinated biphenyls, connectors, plastic casings. Polybrominated diphenyl ethers (PBDE) using this substance. PCB, connector, plastic case 4, ]RoHS-specified upper limit of six harmful substances: cadmium: less than 1000ppm lead: less than 1000ppm steel alloy: less than 3500ppm aluminum alloy: less than 4,000 ppm copper alloy: less than 1000ppm hexavalent chromium: less than/kloc-. 6.RoHS is aimed at all electrical and electronic products that may contain the above six harmful substances in the production process and raw materials, mainly including: white goods, such as refrigerators, washing machines, microwave ovens, air conditioners, vacuum cleaners, water heaters, etc. Black household appliances, such as audio-visual products, DVDs, CDs, TV receivers, IT products, digital products, communication products, etc. Power tools, electric electronic toys and medical electrical equipment