Restriction of Hazarous Substances (RoHS) is the banning of six hazardous substances. These substances are lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl and polybrominated biphenyl ethers.
These substances are limited to 1000 parts per million (0.1%), with the exception of cadmium, which is restricted to 100 parts per million (0.01%). For the printed circuit board industry, the restrictions on lead and polybrominates (used as flame retardants in plastics, i.e. epoxy resins) are far-reaching.
