Alternatives to materials proscribed by the RoHS Directive

Introduction

The materials proscribed by the RoHS Directive are lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and two brominated diphenyl ethers.

Within the electrical and electronics industries, most concern has been voiced over the proscription of lead, since it is used in the solders that are a fundamental requirement for the assembly of nearly all products.

Whilst there are considerable technical challenges in moving to Lead-Free, the alternative materials and processes that can be used are both well established and, in some cases, have been used for many years.

Also, the places where lead is likely to be found in the electrical and electronics manufacturing process are reasonably well known and thus there are unlikely to be too many concerns about lead appearing unexpectedly.

This is not necessarily the case with the other materials that have been proscribed and, for example, cadmium and hexavalent chromium can be found in a wide range of applications that may become increasingly less obvious and obscure as you move up through the supply chain. For example, cadmium might be used as a pigment in a thermoplastic polymer, which in turn might be used as a cable sheathing in a wiring loom of a particular sub-assembly that is incorporated into an electronic module. It is therefore vitally important that all members of the electronics supply chain are aware of the possible places where proscribed materials may be found and that suitable alternatives are identified which comply with the legislation.

Alternatives for:

Lead

Mercury

Cadmium

Hexavalent Chromium

Polybrominated diphenyl ethers and polybrominated biphenyls

Summary