Capacitors can contain hazardous chemicals such as polychlorinated biphenyls (PCBs), lead, cadmium, and other heavy metals. PCBs were historically used in capacitors as a dielectric fluid due to their excellent insulating properties. Although their use has been largely phased out, older capacitors may still contain PCBs, posing a risk during disposal. Additionally, modern capacitors may use electrolytes that are corrosive or toxic if released.
