RoHS and RoHS Substances

What is RoHS?

Let understand what does RoHS compliant mean; RoHS is a directive that was legitimately accepted in July 2006 by the European Union (EU), for the purpose of defending both people and the environment from harmful chemicals found normally in electronics and electrical products.

Main aim of RoHS directive or RoHS standard is to reduce the hazardous elements that are faced in everyday life and which affects our ecosystem.

The use of the RoHS directive is not only related to apparatus manufactured in the European Union, it also relates to items imported in European Union.

RoHS full form

RoHS full form is, “Restriction of Hazardous Substances”.

What is RoHS 1 and RoHS 2?

RoHS 1

The RoHS 1 directive took effect on 1 July 2006, and is compulsory to be imposed and became a law in each EU member state.

This directive limits (with exclusions) the use of six hazardous materials in the manufacture of many types of electronic and electrical equipment and components.

It is thoroughly related with the Waste Electrical and Electronic Equipment Directive (WEEE) 2002/96/EC which sets collection, recycling and recovery objectives for electrical goods and is part of a statutory initiative to solve the difficulty of vast amounts of toxic or poisonous electronic waste.

RoHS is frequently states to the European Union standard, unless otherwise qualified.

RoHS 2

The RoHS 2 directive (2011/65/EU) is a development of the original directive and became law on 21 July 2011 and took effect 2 January 2013.

It talks about the same substances as the original directive while refining regulatory situations and legal simplicity.

It needs periodic re-evaluations that simplify regular expansion of its requirements to cover extra electronic and electrical equipment, cables and spare parts. The CE logo now designates compliance and RoHS 2 declaration of conformity.

RoHS logo

RoHS did not need any particular product marking i.e. RoHS logo, but many companies have implemented their own compliance marks to decrease confusion. Below are some examples of RoHS logo's;

RoHS Symbol

RoHS Symbol

RoHS Symbol

RoHS Symbol

RoHS Symbol

Chinese RoHS marking consist of a lower case "e" within a circle with arrows.

Chinese RoHS Symbol
Chinese RoHS Symbol

RoHS Substances

RoHS is frequently stated as the "lead-free directive", but it restricts the use of the following ten substances which is called as RoHS substances:

1) Lead (Pb) - Lead mainly used in the making of batteries, televisions and computer monitors. RoHS restricts on the use of lead to 1000ppm.

2) Mercury (Hg) - Mercury has been used in the production of fluorescent lamps, hig and low pressure mercury- vapor lamps, printed circuit boards, aluminum electroplating, thermostats and fuel cells. The RoHS directive restricts the use of mercury to 100ppm.

3) Cadmium (Cd) – Cadmium used as a stabilizer for some plastics, also used in cadmium/nickel batteries, electroplating, pigment production, for soldering, brazing alloys, alarm systems, automatic sprinklers and nuclear shielding. It has been restricted by RoHS to 100ppm.

4) Hexavalent chromium (Cr6+) - It is used in photography, paints, plastics and stainless steel products. It is restricted by RoHS to 1000ppm.

5) Polybrominated biphenyls (PBB) – It is used in flame- retardants, plastic foams, and certain plastics used in home electrical appliances. It is restricted by RoHS to 1000ppm.

6) Polybrominated diphenyl ether (PBDE) - They are used in household electronics, printed circuit boards and capacitors. It is restricted to 1000ppm.

7) Bis(2-ethylhexyl) phthalate (DEHP)

8) Butyl benzyl phthalate (BBP)

9) Dibutyl phthalate (DBP)

10) Diisobutyl phthalate (DIBP)

DEHP, BBP, DBP and DIBP were additional added as part of DIRECTIVE (EU) 2015/863 which was issued on 31 March 2015.

RoHS Certification or RoHS Implementation

  • The purpose of the RoHS regulations is to decrease the intensities of the hazardous substances within electronic equipment or component. 
  • It may be essential to carry out RoHS testing to confirm that products are free of the substances banned under the RoHS regulations.
  • With the throw or dumping of electronic instruments or components, it has been found the levels of hazardous substances in the environment have been increasing.
  • One of the main areas of the RoHS has been to decrease the level of lead. However as seen above there are many more substances other than lead also involved in the legislation.
  • In order to limit or control the levels of substances maximum acceptable levels are fixed for the substances.
  • Maximum concentrations of 0.1% by weight of similar material are set for all except Cadmium, which is more poisonous; the maximum level is set to 0.01%.
  • These limits do not applicable to a whole product; it is applicable to any element, component or substance that could be separated from it.
  • In an example this could apply to the solder used in a printed circuit board. It could similarly apply to the plastic insulation of a wire. In this way, the whole thing that is used in the manufacturing of a product must be RoHS compliant.
  • Manufacturers of electronic equipment have been to implement soldering processes that are lead free to deliver RoHS compliance.
  • It also sets limits of 5 ppm mercury and 20 ppm cadmium to batteries excluding those used in medical, emergency, or handy power-tool devices.
  • Producers of electronics and electrical equipment’s or components within the scope of the RoHS directive are liable for confirming that their products meet the requirements of the RoHS directive.
  • Moreover, the act of employing a product in the market is an affirmation by the producer that the product complies with the RoHS directive.
  • It is essential that producers can prove the compliance of any product that they place in the market by obtaining and maintaining necessary technical documentation.
  • The RoHS necessities relate to the end products that fall within the scope of the RoHS directive.
  • The components and sub-assemblies used within the end products are not precisely covered by the scope of the RoHS directive and so no need to comply with the directive.
  • Though, as a final product is made up of components and sub-assemblies it is expected that all components and group of components forming sub-assemblies in the final product must not contain any of the restricted substances above the defined maximum concentration limits.
  • To validate compliance, a manufacturer must show that all the components, materials, sub-assemblies that involved in the product are RoHS compliant.
  • To avoid costly testing of all components, the easiest way to do this is to get certification from that supplier.
  • Manufacturers are also estimated to execute certain compulsory analysis of components. Technical documents must be present as a part of the CE Marking procedure.

RoHS application

The RoHS directive relates to a extensive range of products. The scope of the directive relates to equipment that is defined in the WEEE directive. These include:
  • Large and small household applications or appliances
  • IT related equipments
  • Telecommunication related equipment
  • Equipment for consumer applications
  • Lighting equipment
  • Electronic and electrical tools
  • Toys and sports equipment
  • Semiconductor devices
  • Automatic vending machines
One of the main exceptions from the RoHS directive is the batteries, which are not involved in RoHS, in spite of the high levels of substances that would usually come under RoHS.

The RoHS Directive does not apply to the glass used in cathode ray tubes and fluorescent tubes. Mercury-vapor light bulbs are also not considered in RoHS.


The RoHS directive is intended for eliminating certain hazardous substances from electrical and electronic equipment’s or components. Producers of these equipment’s or components within the scope of the directive are liable for confirming that their products meet the necessities of the RoHS directive.
The RoHS necessities apply to the final products that fall within the range of the RoHS directive. Though, as an end product is made up of many components and sub-assemblies it is expected that all components and sub-assemblies must not cover any of the prohibited substances above the defined maximum concentration limits.

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