The RoHS Directive restricts the use of six specific hazardous substances in EEE: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE). These substances are known to have a range of negative impacts on human health and the environment, including causing cancer, damaging the nervous system, and causing birth defects.