Restriction of Hazardous Substances
Various territories around the world have brought in legislation to limit the levels of some (polluting) substances that are used in electronic equipment. In the EU, the legislation became law in July 2006 and limits were set for lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers. This has meant the electronics industry has had to respond by producing RoHS-compliant components and materials. It is important during the design process to select these parts in order to ensure the completed assembly will itself be RoHS-compliant.
The main target market for the RoHS directive was the commercial electronics market with exemptions being allowed in a number of market sectors including medical and monitoring & control equipment. The RoHS2 directive came into force 2nd January 2013 and gradually increases the scope of the original RoHS directive to include all electrical and electronic equipment. From July 2014 category 8 medical devices and category 9 monitoring & control instruments were included. July 2016 sees the directive extended to category 8 in-vitro medical devices (not implants), while category 9 industrial monitoring and control instruments come under the scope in July 2017. Finally, in July 2019 it is extended to all electrical & electronic equipment except for those specifically excluded.
Batteries are not within the scope of the directive, and neither is equipment to support R&D activities.
One particular point to note is that it is necessary to include RoHS compliance in the declaration of conformity for a product when placing it on the market.