International Metric System (SI), RoHS and WEEE
Other common units can be derived from the base units. Most of the units that are used in electricity are derived ones. Example: Ohm, Volt, Hertz. Exception: Electric Current (ampere)
RoHS, also known as Lead-Free, stands for Restriction of Hazardous Substances. RoHS Directive 2002/95/EC restricts the use of six hazardous materials found in electrical and electronic products. All applicable products in the EU market after July 1, 2006 must pass RoHS compliance. RoHS impacts the entire electronics industry.
stands for Waste from Electrical and Electronic Equipment
. WEEE Directive 2002/96/EC mandates the treatment, recovery and recycling of electric and electronic equipment (90% ends up in landfills). All applicable products in the EU market after August 13, 2006
must pass WEEE compliance and carry the "Wheelie Bin" sticker.