How Does the Restriction of Hazardous Substances (RoHS) Directive Apply to Heating Plates?

The Restriction of Hazardous Substances Directive, or RoHS, limits the use of particular hazardous compounds in electrical and electronic equipment marketed in the EU. This directive also applies to heating plates with electronic controls. Compliance is obligatory for access to the market.

RoHS Directive - What is it?
The RoHS Directive (2011/65/EU, RoHS 2 and further changes in RoHS 3) intends to limit the concentration of certain hazardous compounds in electrical and electronic equipment so as to lessen the hazards associated with these materials for the environment and human health. The directive applies to all products sold in the EU and sets maximum permitted concentrations for banned chemicals.

RoHS limits the amount of the following substances in homogenous materials (components that cannot be mechanically separated):

Lead (Pb): not to exceed 0.1% by weight

Mercury (Hg): Max. 0.1 % by weight

Cadmium (Cd): Max. 0.01% by weight

Hexavalent chromium (Cr(VI)) Max 0.1% by weight

Polybrominated biphenyls (PBB): 0.1% by weight max

Polybrominated diphenyl ethers (PBDE) Max 0.1% by weight

The regulation limits certain compounds in components, materials and the end product, ensuring safe disposal and decreasing the potential for harm to consumers and the environment.

Heating Plates RoHS Compliant
RoHS compliance is required for the sale of heating plates with electrical parts such as resistance wires and electronic controls in the European market. The following are components which are subject to scrutiny under RoHS:

Heating Elements 
Resistance wire: The heating element in the plate which produces heat by passing electricity through it must not contain banned materials like lead and mercury.

Solder joints: The solder used for the installation of heating elements and control electronics should be lead free. Leaded solder is forbidden, particularly for usage in high temperature locations.

Plating: Any cadmium plating used for corrosion resistance or conductivity must be replaced by compliant alternatives. Cadmium plating is totally banned under RoHS.

Electronic Control Units
Controller boards and components : The PCB (Printed Circuit Board) and other components used in the temperature controlling systems of heating plates also need to be RoHS compliant. This includes making sure that there is no lead or any other banned compounds used in the soldering process.

Switches and connections: All electronic components in the control system such as switches and connectors must not contain banned substances over the maximum permissible limit.

Coatings (external)
RoHS rules must be respected for the external coatings of the heating plates, especially if they contain flame retardants. These materials such as Polybrominated Biphenyls (PBB) and Polybrominated Diphenyl Ethers (PBDE) are banned and need to be replaced with RoHS compatible alternatives.

Demonstration of Compliance
RoHS compliance is often demonstrated by a range of documents and testing:

Supplier declarations: Manufacturers require suppliers to provide declarations that materials used in components comply with RoHS requirements.

Material test reports: These reports confirm that certain materials and components contain no banned chemicals.

Technical file: The technical file has to be maintained including documents on the materials, conformity tests and product information.

CE Marking The CE mark on heating plates indicates the product is compliant with EU rules, including RoHS. CE mark is a declaration of conformity with all relevant European standards.

RoHS Limited Substances
Substance Maximum Concentration 
Lead (Pb) 0.1 % wt
Mercury (Hg) 0.1% by weight
Cadmium (Cd) 0.01 wt%
Hexavalent chromium (Cr(VI)) 0.1% by weight
Polybrominated biphenyls (PBB) 0.1% w/w
Polybrominated diphenyl ethers (PBDE) 0.1% by weight Exceptions and considerations
Most electrical and electronic equipment is covered by RoHS although there are several exclusions. For example, lead may still be utilised in some high temperature soldering applications such as those found in some types of heating equipment. These exemptions are narrow and must be well documented for compliance.

Summary
RoHS compliance is mandatory for heating plates sold in the EU market and is a sign of an increasing environmental conscience in production. Manufacturers must guarantee that heating plates and their components comply with the limits for prohibited substances as laid down in the RoHS Directive and be able to prove conformity by documentation and testing.

As regulatory requirements vary, firms must be aware of changes in RoHS and other environmental legislation. RoHS compliance is extremely important not just for market access but also for making a positive contribution to a safer and more sustainable manufacturing process. The manufacturers have to meet these criteria since regulatory compliance has become a key feature of global market access.