The RoHS directive restricts the use of six hazardous materials in the manufacture of various types of electrical and electronic equipment (lead, mercury, cadmium, chromium hexavalent, polybrominated biphenyl (PBDE) and bis(2-ethylhexyl) phthalate). This approval sets maximum limits for the amount of these substances that may be present in electrical and electronic equipment. It is closely related to the Waste Electrical and Electronic Equipment Directive.