Control of Heavy Metals
In September 2000, the European Union issued an END OF LIFE VEHICLE DIRECTIVE (ELV) (2000/53/EC) which is designed to ensure the recycling of scrap motor vehicles. To assist in this, the Directive limits the use of toxic heavy metals in motor vehicles. This covers lead, cadmium, mercury and hexavalent chromium. In metal finishing, cadmium was mostly phased out for vehicles by about 1996. Lead is only present in galvanising. Hexavalent chromium was the main constituent in passivate (conversion coatings) used on zinc plating and in inhibitors. The ELV originally allowed 2 gm of hexavalent chromium per motor vehicle (from July 2003). This was changed, however, in June 2002. A revision was made, abandoning the 2003 requirement and requiring a total ban in the use of hexavalent chromium for all motor vehicles (less than 3.5 tonnes in weight) sold after July 2007. The Directive allows a trace of hexavalent chromium, provided it is not introduced intentionally.
The effective banning of hexavalent chromium has caused important changes in the coatings used by the Finishing Industry. Hexavalent chromium was an effective, cheap, passivating material that had good self healing properties on damaged films. It could be used in weak solutions to give effective films with short immersion times.
The hexavalent chromium free replacements usually make use of trivalent chromium, which is regarded as a non-toxic compound of chromium. In some respects, this is not as effective as the previous materials, but techniques have been developed, often using added sealants to extend coating performance to be superior to the old systems. Details of these are given in the appropriate sections.
The Anochrome Group has been monitoring the environmental effects of its products for some time. All bought in materials, emissions, water used and waste products have to be assessed to minimise their environmental impacts wherever possible.
To assess the true Environmental Impact of a coating and its application, the environmental advantages of the coating must be investigated, as well as the disadvantage to the environment of obtaining the raw materials and application processes used.
A zinc coating on steel can more than double the useful life of a component – with larger increases for higher thicknesses.
The parameters considered to arrive at the environmental “scores” are below
1. Raw material production methods.
2. Coating processing techniques.
3. Water – solvent usage and treatment.
4. Energy usage.
5. Advantages, corrosion protection and other properties of the coating of coating.
6. Any disposal problems at end of life.
Introduction to RoHS
RoHS (Restriction of certain use of Hazardous Substances) is an EU Directive that restricts the use of 6 hazardous materials in the manufacture of electronic & electrical equipment (See affected products).
The legislation came into force on 1st July 2006
It is closely linked with, and takes its scope from, the WEEE(Waste Electrical and Electronic Equipment) Directive.
RoHS is having a fundamental impact on the electronics industry.
Legally it applies within the EU only, however RoHS is effectively becoming a world-wide standard due to the global nature of this industry.
Similar environmental legislation is also being considered in a number of countries outside the EU.
RoHS is not solely a technical manufacturing problem. It has major implications for other aspects of business including
• Product design
• Customer and supplier relations
• Logistics and supply chain management
• Large household appliances
• Small household appliances
• Telecommunications equipment
• Electrical and electronic tools
• Lighting equipment
• Consumer equipment
• Toys, leisure and sports equipment
• Automatic dispensers
The RoHS Directive takes its scope from the associated WEEE
(Waste Electrical and Electronic Equipment) Directive.
The RoHS Directive affects all the product types above plus:
•Medical devices (with the exception of implanted andinfected products)
•Monitoring and control instruments
The Anochrome Group is keeping itself informed of the Registration, Evaluation, Authorisation & Restriction of Chemicals legislation and will ensure its suppliers are kept aware of their responsibilities