RoHS is a mandatory standard formulated by EU legislation. Its full name is the "Restriction of Hazardous Substances" directive, which aims to restrict the use of certain hazardous substances in electrical and electronic equipment. The standard officially came into effect on July 1, 2006. It is mainly used to standardize the material and process standards of electrical and electronic products to make them more conducive to human health and environmental protection. The purpose of this standard is to eliminate six substances in electrical and electronic products, namely lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (note: the correct Chinese name of PBDE refers to polybrominated diphenyl ethers, and the term "polybrominated diphenyl ethers" is an incorrect statement). And it specifically stipulates that the lead content should not exceed 0.1%.

RoHS Summary and Requirements:
Restricted Toxic Substances:

· Heavy Metals:

· Lead (Pb)

· Mercury (Hg)

· Cadmium (Cd)

· Chromium (VI) (Cr6+)

· Certain Brominated Flame Retardants:

· Polybrominated biphenyls (PBBs)

· Polybrominated diphenyl ethers (PBDEs)

The maximum limit indicators are:

· Cadmium: 0.01% (100 ppm)

· Lead, Mercury, Hexavalent Chromium, Polybrominated Biphenyls, Polybrominated Diphenyl Ethers: 0.1% (1000 ppm)

The RoHS directive restricts the use of the following six types of hazardous substances:

1. Lead (Pb). Examples of its use: solder, glass, PVC stabilizers.

2. Mercury (Hg) (Mercury). Examples of its use: thermostats, sensors, switches and relays, light bulbs.

3. Cadmium (Cd). Examples of its use: switches, springs, connectors, casings and PCBs, contacts, batteries.

4. Hexavalent Chromium (Cr6+). Examples of its use: metallic anti-corrosion coatings.

5. Polybrominated Biphenyls (PBBs). Examples of its use: flame retardants, PCBs, connectors, plastic casings.

6. Polybrominated Diphenyl Ethers (PBDEs). Examples of its use: flame retardants, PCBs, connectors, plastic casings.

Testing Principles:
According to the requirements of the EU WEEE & RoHS directives, CES splits products according to their materials and conducts tests for hazardous substances on different materials separately. Generally speaking:

· For metal materials, four harmful metal elements need to be tested, such as cadmium (Cd), lead (Pb), mercury (Hg), and hexavalent chromium (Cr6+).

· For plastic materials, in addition to checking these four harmful heavy metal elements, brominated flame retardants (polybrominated biphenyls (PBBs)/polybrominated diphenyl ethers (PBDEs)) also need to be tested.

· At the same time, packaging materials of different materials also need to be tested for heavy metals in packaging materials respectively (94/62/EEC).

The following are the upper limit concentrations of the six hazardous substances specified in RoHS:

· Cadmium: less than 100 ppm

· Lead: less than 1000 ppm; less than 3500 ppm in steel alloys; less than 4000 ppm in aluminum alloys; less than 40000 ppm in copper alloys

· Mercury: less than 1000 ppm

· Hexavalent Chromium: less than 1000 ppm

Reasons for Introducing RoHS
The first time it was noticed that electrical and electronic equipment contained heavy metals harmful to human health was in 2000 when the Netherlands found cadmium in the cables of a batch of game consoles sold on the market. In fact, in the production of electrical and electronic products, the solder widely used and the ink for packaging box printing both contain harmful heavy metals such as lead.

When RoHS is Implemented
The EU implemented RoHS on July 1, 2006. At that time, electrical and electronic products that use or contain heavy metals, as well as flame retardants such as polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) and exceed the limit values will not be allowed to enter the EU market.

Scope of Application of RoHS Certification
The 27 member states of the EU: France, Germany, Italy, the Netherlands, Belgium, Luxembourg, the United Kingdom, Denmark, Ireland, Greece, Spain, Portugal, Austria, Sweden, Finland, Cyprus, Hungary, the Czech Republic, Estonia, Latvia, Lithuania, Malta, Poland, Slovakia, Slovenia, Bulgaria, Romania.

Which Products are Specifically Involved in RoHS?
RoHS applies to all electrical and electronic products in which the above six hazardous substances may be contained during all production processes and in raw materials. It mainly includes: daily household appliances, such as refrigerators, washing machines, microwave ovens, air conditioners, vacuum cleaners, water heaters, etc.; black household appliances, such as audio and video products, DVDs, CDs, television receivers, IT products, digital products, communication products, etc.; power tools, electric and electronic toys, medical electrical equipment.

Current Progress of RoHS
Some large companies have already noticed RoHS and started to take countermeasures. For example, SONY's digital cameras have stated on the packaging box: This product uses lead-free soldering; it uses lead-free ink for printing.
In 2004, the Ministry of Information Industry also issued the "Administrative Measures for the Prevention and Control of Pollution of Electronic Information Products", the content of which is similar to RoHS. In October of the same year, the "Working Group on Standards for the Prevention and Control of Pollution of Electronic Information Products" was established to study and establish a standard system for the prevention and control of pollution of electronic information products that is in line with China's national conditions; to carry out standard research, formulation, and revision related to the prevention and control of pollution of electronic information products, especially to accelerate the formulation of basic standards such as materials, processes, terms, testing methods, and experimental methods urgently needed by the industry.
On July 1, 2011, the EU published the new version of the RoHS directive - Directive 2011/65/EU in the Official Journal (OJ).
As a directive well-known to Chinese electrical and electronic product manufacturing enterprises, its introduction process has been full of twists and turns. Due to significant differences among various parties during the revision process, this amendment, which was originally intended to be introduced in 2009, has been postponed again and again. In particular, regarding whether to expand the product scope and the scope of restricted substances, there have been intense debates within the EU, including the Commission, the European Parliament, the Council, the industry, and NGOs.
The main differences between 2011/65/EU and the original RoHS directive 2002/95/EU are as follows:

1. Expand the product scope: All electrical and electronic products are covered within the scope of the directive's regulation (including cables and spare parts). However, a certain transition period is given to the newly added Category 8 medical devices and Category 9 monitoring and control instruments (including industrial monitoring instruments). In addition, 20 exemptions are provided for these two categories of products (listed in Annex IV).

2. Clarify some definitions.

3. The scope of controlled substances has not been expanded, and the original limit requirements for the original six substances are still maintained. However, it is proposed that during future review processes, substances including DEHP should be prioritized for investigation, paving the way for the directive to expand the scope of controlled substances in the future.

4. Delete the provisions of "producer" and add the definitions of "manufacturer", "authorised representative", "importer", and "distributor", and clearly define their responsibilities.

5. Stipulate that products need to be affixed with the CE mark and related matters of the CE mark.
This directive will come into effect on the 20th day after its publication in the OJ, and member states need to transpose it into their national laws by January 2, 2013.
The publication of 2011/65/EU will have a certain impact on Chinese electrical and electronic product manufacturing enterprises. Especially, since medical device products and monitoring and control instrument products are included in the scope of regulation, the impact on the manufacturing enterprises of these two categories will be very significant.
In addition, since electrical and electronic products need to be affixed with the CE mark, it will also be a huge challenge for the industry to comply with the requirements of the directive.

Commonly Used RoHS Testing Methods

1. Anions: Ion Chromatography with Metrohm Inline Technology
After oxygen bomb combustion and pre-treatment with Metrohm Inline Technology, it directly enters the ion chromatograph for analysis.

2. Cations and Their Valence States:
They can be detected by Metrohm cation chromatography, ion selective electrode method, and atomic absorption method.
The valence states of cation elements can be analyzed by voltammetry polarography.

The pronunciation of RoHS: /rous/
The testing methods can refer to IEC62321:2008, "Determination procedures for the concentrations of six restricted substances in electrical and electronic products".
A. First, use XRF for non-destructive screening, which is fast, efficient, non-destructive, and low-cost. However, there are many interfering factors and relatively large errors.
B. After microwave digestion and acid digestion, use AAS or ICP-AES to determine the concentrations of Pb, Cd, and Hg.
C. After Soxhlet extraction, use GC-MS to determine the concentrations of polybrominated biphenyls, polybrominated diphenyl ethers, etc.
D. Use the spot test method or the boiling water extraction method to determine the concentration of colorless surface layer Cr6+, or use an ultraviolet-visible spectrophotometer to test according to EPA3060A.

RoHS Certification
RoHS is a mandatory standard formulated by EU legislation. Its full name is the "Restriction of Hazardous Substances" directive, which aims to restrict the use of certain hazardous substances in electrical and electronic equipment. The standard officially came into effect on July 1, 2006. It is mainly used to standardize the material and process standards of electrical and electronic products to make them more conducive to human health and environmental protection. The purpose of this standard is to eliminate six substances in electrical and electronic products, namely lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers. And it specifically stipulates that the lead content should not exceed 0.1%. The main sources of lead involved are as follows.

Basic Content of the EU RoHS and WEEE Directives
The European Parliament and the European Commission issued the "Waste Electrical and Electronic Equipment" directive (referred to as the "WEEE directive") and the "Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment" (referred to as the "RoHS directive") in their "Official Journal" on February 13, 2003.
The RoHS directive and the WEEE directive stipulate that there are ten categories and 102 types of products included in the management of hazardous substance restrictions and waste recycling management. The first seven categories of products are all the main electrical products exported by China. They include large household appliances, small household appliances, information and communication equipment, consumer products, lighting equipment, electrical and electronic tools, toys, leisure and sports equipment, medical equipment (excluding implanted or infected products), monitoring and control instruments, and vending machines.
On December 3, 2008, the EU issued the revised proposals for the WEEE directive (2002/96/EC) and the RoHS directive (2002/95/EC). The purpose of this proposal is to create a better regulatory environment, that is, simple, understandable, effective, and enforceable regulations. The main contents of the RoHS directive revision are as follows:

1. Change the legal terms and clarify the scope and definition of the directive.

2. Introduce the CE mark of the product and the EC declaration of conformity.

3. Incorporate medical devices, control and monitoring instruments into the scope of the RoHS directive in stages.

4. The six restricted hazardous substances have not changed, but four substances - hexabromocyclododecane (HBCDD), bis(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), and dibutyl phthalate (DBP) - are required to be evaluated preferentially to consider whether they will be included in the scope of restricted substances in the future.

RoHS Scope:
Only for products placed on the market as of July 1, 2006.