Environmental consequences of Cadmium
NiCd batteries contain cadmium, which is a toxic heavy metal and therefore requires special care during battery disposal. In the United States, part of the price of a NiCd battery is a fee for its proper disposal at the end of its service lifetime. In the European Union, the Restriction of Hazardous Substances Directive (RoHS) bans the use of cadmium in electrical and electronic equipment products since July 2006. The sale of nickel-cadmium batteries has now been banned within the European Union except for medical use; alarm systems; emergency lighting and portable power tools. This last category is to be reviewed after 4 years.
Cadmium, being a heavy metal, can cause substantial pollution when landfilled or incinerated. Because of this, many countries now operate recycling programs to capture and reprocess old NiCd batteries.