From 2 January 2013, the use of cadmium is permitted in photoresistors for analogue optocouplers applied in professional audio equipment. This is the result of an exemption to the RoHS Directive adopted by the Commission, which otherwise prohibits the use of cadmium in electrical and electronic equipment. The Commission determined that the substitution of cadmium in those photoresistors is still technically impracticable. However, the exemption is limited in time, since the Commission considers that the research for cadmium-free technology is in progress and substitutes could become available by the end of 2013.
The full text of the exemption is available here: