RoHS is the shortened term for the "Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment," or commonly "Restriction of Hazardous Substances." It is a directive adopted by member countries of the European Union in 2004 controlling the the use of six hazardous materials in the manufacturing of electronic equipment. It is closely linked with the Waste Electrical and Electronic Equipment Directive, also known as WEEE.
The substances covered by RoHS are lead, cadmium, mercury and hexavalent chromium metals, as well as polybrominated biphenyl and polybrominated diphenyl ether flame retardants. They are controlled because they are dangerous to manufacturer employees and recyclers--they are also considered polluting to the environment if not disposed of properly. To be in compliance with RoHS, products must not exceed set amounts of any of these substances in their composition.
Concentrations of RoHS Substances
Products which exceed set amounts of the chemicals covered in RoHS are not in compliance with European law. Lead, mercury, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers must not exceed a maximum concentration level of 0.10 percent. Cadmium is prohibited from exceeding a maximum concentration of 0.01 percent.
Examples of Products Containing RoHS Substances
Some products which typically contain RoHS restricted substances include: solders, PVC cable covers for electronic equipment, pigments, paints, fuses, glass, washers, switches, lamps and light bulbs. Even if a product does not contain excessive amounts of a RoHS substance overall, a single component within the product can cause the product to fail compliance standards by testing too high.
RoHS Compliance Testing
Companies which specialize in testing products for RoHS compliance levels use X-ray fluorescence spectrometers in their analysis. They work by sending out an intense X-ray beam and exciting atoms within the target. X-rays are reflected back from the sample along a spectrum of wavelengths characteristic of the types of atoms present in the sample, giving the tester a reading of the amount of each material in a product.
Non-compliance to RoHS standards or failing to comply with requests for documentation can result in serious fines, sanctions or prosecution. Penalties vary from country to country, but can include steep fines and products being denied for export. In Ireland, Poland and several other countries, non-compliance with RoHS can be punishable by a prison term.