What is RoHS?

The acronym RoHS (often pronounced “ro-hoss”) is popping up more and more these days in connection with the electrical and electronics industries, but do you know the meaning behind it? Standing for the Restriction of Hazardous Substances, RoHS is a directive that was officially adopted in July 2006 by the European Union, for the purpose of protecting both people and the environment from hazardous chemicals found in both electronics and electrical products.

Since July 1, 2006, all electrical and electronic products to be sold within the European Union are required to comply with the RoHS materials requirements. It’s likely that you’ve heard RoHS referred to as the “lead-free directive”, but it actually restricts the use of six different materials, and lists their allowable levels in parts per million (ppm):

• Lead: lead is primarily used in the production of batteries, televisions and computer monitors. RoHS restricts the use of lead to 1000ppm.
• Mercury: Mercury has been used in the manufacture of fluorescent lamps, mercury- vapor lamps, printed circuitry, aluminum electroplating, thermostats and fuel cells. The RoHS directive limits the use of mercury to 100ppm.
• Cadmium: Cadmium, which has been limited by RoHS to 100ppm, can act as a stabilizer for some plastics, and is used in cadmium/nickel batteries, electroplating, pigment production, solders, brazing alloys, alarm systems, automatic sprinklers and nuclear shielding.
• Hexavalent Chromium: Hexavalent chromium, which is used in photography, paints, plastics and stainless steel products, is limited by RoHS to a level of no more than 1000ppm.
• Polybrominated biphenyls (PBB): Polybrominated biphenyls, which are used in flame- retardants, plastic foams, and certain plastics used in home electrical appliances, have been limited by RoHS to 1000ppm.
• Polybrominated diphenyl ethers (PBDE): Polybrominated diphenyl ethers are used in household electronics, printed circuit boards and capacitors. RoHS limits the use of PBDE to 1000ppm.