RoHS is a directive for Restriction of Hazardous Substances that was adopted by European Union in February 2003 and took effect from July 1, 2006. Having close linkages with the Waste Electrical and Electronic Equipment Directive (WEEE); it restricts the usage of 6 hazardous substances in electrical and electronic equipment. RoHS applies to all goods that are in Europe, manufactured or imported. But, the European Union members can have their own enforcement and implementation policies.

As per the directive though, the manufacturers of electrical and electronic equipment would need to keep the levels of the following six substances to the agreed limits:

1. Mercury (Hg) limited to less than or equal to 100 parts per million (ppm)
2. Lead (Pb) limited to less than 0.1% of the substance by weight at raw homogeneous materials level
3. Hexavalent chromium (Hex- Cr) limited to less than 0.01% of the substance by weight at raw homogeneous materials level
4. Cadmium (Cd) limited to less than 0.01% of the substance by weight at raw homogeneous materials level
5. Polybrominated biphenyl (PBB) flame retardants limited to less than 0.1% of the substance by weight at raw homogeneous materials level
6. Polybrominated diphenyl ether (PBDE) flame retardants limited to less than 0.1% of the substance by weight at raw homogeneous materials level

WEEE and RoHS deal with different parts of product life.

WEEE focuses at reducing the quantity of electrical and electronic waste being dumped in landfills and RoHS focuses at reduction of the quantity of hazardous materials used in manufacturing them. The WEEE has set targets for collection, treatment, recovery, recycle and disposal of electrical goods as a measure to deal with the increasing toxic e-waste. RoHS takes its scope from WEEE, as in spite of these measures, the toxic waste management problem would not be resolved unless the content of the 6 hazardous substances mentioned above is limited. Thus, the recycling process would still pose risks to health and environment.

There are 10 categories that fall under the scope of WEEE and hence in the scope of RoHS. But as of now categories 8 and 9 are exempt from RoHS. The categories are:

1. Large household appliances
2. Small household appliances
3. IT and telecommunications equipment
4. Consumer equipment
5. Lighting equipment
6. Electrical and electronic tools (with the exception of large-scale stationary industrial tools)
7. Toys, leisure and sports equipment
8. Medical devices (with the exception of all implanted and infected products)
9. Monitoring and control instruments
10. Automatic dispensers

The directive does not apply to some medical and military equipment in the EU, to fixed industrial plants & tools and applies only to the finished products. As per the directive, a lot of responsibility and onus has been shifted to the manufacturers for the compliance. The RoHS directive is not just a European issue, but similar requirements are being adopted elsewhere as well.

There is a China RoHS with similar restrictions, but its application and implementation is different from EU RoHS. EU RoHS is said to include all products unless specifically exempted whereas there would be a list of the products included in the China RoHS. The implementation of RoHS in China is with the Ministry of Information Industry (MII) and it took effect from 1 March, 2007. It requires only disclosure of all 6 EU RoHS substances. This is an initial step that would require manufacturers to have the requisite markings but after some time a catalogue is expected to be released where actual limits for hazardous substances will have to be complied with by the specified products.

RoHS directive has received criticism as well, in terms of the high cost of compliance and negative impact on product quality. There are also reports of increased usage of less environment friendly alternatives due to restrictions on use of lead.

Exemptions and requests and other issues pertaining to the gaps in compliance, enforcement and implementation of the directive are under consideration.