RoHS and its Importance

RoHS stands for “restriction of hazardous substance“. The term was coined by European Union (EU) in the year 1998 after it noticed alarmingly large quantities of hazardous waste being dumped into landfill sites. The volumes of these wastes were likely to increase 3-5 times faster than the average municipal waste. This indicated a very fast growing source of environmental contamination. RoHs is often referred to as the “lead-free” legislation, but it restricts the use of the following six substances:

1.Lead (Pb):- LEAD is mostly used and thus requiring the most attention. This is also the case for the entire electronics industry. Any cable sold with the RoHS qualification should be manufactured as such: Lead - Significant use in terminal finish for connectors/components, PWB board finish and solder for

PWB assembly; use as UV/heat stabilizer in PVC cable jackets.

2.Mercury (Hg):- Not used.

3.Cadmium (Cd):- Very limited use as colorant for plastic materials.

4.Hexavalent Chromium (Cr6+):- Limited use as corrosion protection for retention hardware (e.g. screws, washers); limited use as conversion coating for metallic housings.

5.Polybrominated biphenyls (PBB):- Very limited use as flame retardant in plastic materials.

6.Polybrominated Diphenyl Ether (PBDE):- Very limited use as flame retardant in plastic materials.

Maximum allowed concentration values are:-

1.Up to 0.1 per cent by weight (1000 PPM) in standardized materials for lead, mercury, hexavalent chromium, PBBs and PBDEs.

2.Up to 0.1 per cent by weight (1000 PPM) in standardized materials for cadmium.

Note that not all electronic equipment fall within the scope of these regulations. For example, batteries are considered to be an ‘old area’ product and not currently covered by the regulations. Similarly, electronic equipment intended to product national security, or with a military purpose, is exempted.

To deal with this problem, the member states of the EU decided to create the waste electrical and electronics equipment (WEEE) directive, whose purpose is to:-

I.Improve manufacturers’ designs, to reduce the creation of waste.

II.Make manufacturers responsible for certain phases of waste management.

III.Create systems to improve treatment, refuse and recycling of WEEE.

IV.Promote separate collections of electronic waste.

In 1998, a draft proposal called EEE (Environmental of electrical & Electronics Equipment) was also introduced along the same lines. Now, as the implementation of this policy becomes imminent, this policy is generally referred to as the RoHS directive.

As the restricted materials are hazardous to the environment and dangerous in terms of occupational exposure during manufacturing and recycling, the EU countries adhere to the RoHS. All the applicable products in the EU market after July 1, 2006 must be RoHS compliant. Therefore any business that sells applicable electronics products, sub-assemblies or components directly to EU countries, or sells to resellers, distributors or integrators that, in turn, sell products to EU countries, is impacted if it utilizes any of the restricted materials.

Engineering Services