What is RoHS?

Originally, RoHS (“Restriction of Hazardous Substances”) was the term applied only to EU RoHS.  It is now a generic term for any country’s environmental safety directive having to do (primarily) with reductions in six common hazardous materials routinely found in electronic information products.


The original EU Restriction of Hazardous Substances Directive (EU RoHS) 2002/95/EC became European Law in February 2003. This directive restricts the use of six hazardous materials in the manufacture of various types of electronic and electrical equipment. Often called RoHS 2, DIRECTIVE 2011/65/EU went into effect January 2, 2013.

There are two important differences between RoHS 1 and RoHS 2:

  • RoHS 1 required Certificates of Compliance for the product, a kind of honor system. RoHS 2 added the requirement to have Technical Documentation that demonstrates compliance for every component in the product. This Technical Documentation must be produced for any “a reasoned request from a competent national authority”.
  • RoHS 2 is now part of CE, which in practice means enforcement is higher, and penalties greater than under RoHS 1. RoHS marking is no longer valid, as it is part of CE.

RoHS currently restricts the use of the following six substances in electrical and electronic equipment:

  • Lead
  • Mercury
  • Cadmium
  • Chromium VI (Also known as hexavalent chromium)
  • PBB
  • PBDE

PBB and PBDE are flame retardants used in some plastics.

These four phthalates will become restricted in 2019 and 2021, depending on product category:

  • DEHP
  • BBP
  • DBP
  • DIBP

While the environmental concerns vs. the economic impact continue, these banned substances can cause very serious health problems.

The maximum concentrations are 0.1% (except for Cadmium which is limited to 0.01%) by weight of homogeneous material. This means that the limits do not apply to the weight of the finished product, or even to a component, but to any single substance that could (theoretically) be separated mechanically – e.g. . the sheath on a cable, the tinning on a component lead etc).

As an example, a radio comprises a case, screws, washers, a circuit board, speakers etc. A circuit board comprises a bare PCB, ICs, resistors, switches etc. A switch comprises a case, a lever, a spring, contacts, pins etc. The contact might comprise a copper strip with a surface coating.

Everything that can be identified as a different material must meet the limit. So if it turns out that the switch’s contact coating was gold with 2300 ppm cadmium then the entire radio would fail the requirements of the directive.

Note that batteries are not included within the scope of EU RoHS, therefore Ni-Cd batteries are permitted despite the Cadmium. This is not true for China RoHS (more below).

RoHS applies to these products in the EU whether made there or imported.

For EU RoHS, many exemptions apply.  This is not true for China RoHS.

China RoHS

China RoHS requires stringent marking, and China-approved testing prior to product entry into China.

On November 6, 2006, China’s Ministry of Information signed three standards into law:

  • Marking: labeling and information disclosure
  • Levels: maximum concentration value
  • Testing: testing methods

EU RoHS compared to China RoHS:

  • EU RoHS compliance does not equal China RoHS compliance.
  • EU RoHS has no Marking requirements.  China RoHS Marking requirements are stringent.
  • Many components with EU RoHS certificates will still have hazardous materials which must be disclosed.
  • EU RoHS exempts many components from compliance.
  • China RoHS currently has no RoHS exemptions.


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