Foreword

Development and use of screening methods to determine chromium (VI) and brominated flame retardants in electrical and electronic equipment

The RoHS Directive
In order to limit the long-term human and environmental impact of hazardous substances, the EU has adopted the RoHS Directive which prohibits the marketing of electrical and electronic products containing more than 0.1% lead, mercury, hexavalent chromium, polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) by weight or more than 0.01% cadmium by weight. In this connection the substances comprised are collectively referred to as "RoHS substances".

So far the Directive does not comprise medical equipment, measuring and control equipment and major industrial equipment, and a large number of exemptions have furthermore been granted for applications where substitution is impracticable, or where the negative environmental or health impacts caused by substitution are likely to outweigh the benefits thereof. However, on 16 December 2008, the Commission submitted a proposal to the member states for a recast of the Directive to include medical equipment as well as measuring and control equipment.

The RoHS Directive entered into force on 1 July 2006, and in Denmark the Directive has been implemented by the Executive Order on the restriction of import and sale of electrical and electronic equipment containing certain hazardous substances, Executive Order No. 873 of 11/08/2006.

The RoHS substances have traditionally been used for a large number of purposes, and as electrical and electronic equipment is made up of multiple components, each of which is subject to the RoHS requirements, determining whether a product is compliant with the provisions of the Directive is an extensive task.

The content of lead, cadmium and mercury in individual materials can be determined easily and non-destructively using an X-ray Fluorescence Spectrometry (XRF) screening method. For hexavalent chromium and the two groups of brominated flame retardants, PBDEs and PBBs, the XRF method is not immediately applicable, and there has consequently been a need for the development of relatively simple and cheap screening methods.

Development of a screening method for hexavalent chromium
As part of the drawing up of this guidance, a simple screening method has been developed that can be used to get an indication of whether the products contain hexavalent chromium. The accuracy and reliability of the method has been reviewed in connection with the development work, and this forms the basis of the description of the method in this guidance.

Development of screening method for PBDEs and PBBs
We have also attempted to develop a screening method for PBDEs and PBBs based on thin-layer chromatography. The development work is described in Annex 1 to this guidance. We have succeeded in developing a screening method to determine PBDEs in ABS plastic using thin-layer chromatography. For other types of plastic, extraction of the substances from the plastic materials is very difficult and requires methods that are not suitable for use outside analysis laboratories. As a result, the screening method developed will only cover a small part of the PBDE applications in electrical and electronic products. Due to the limited field of application, the assessment is that the method is not feasible as a general screening method.

Purpose of this guidance
The overall purpose of this guidance is to help importers, producers and control authorities in their inspections of electrical and electronic products by describing the most likely occurrences of the substances as well as low-cost screening methods to determine hexavalent chromium.

Contractors
The screening methods and guidance have been drawn up by the Danish Technological Institute and COWI A/S and are subsidised under the Enterprise Scheme of the Ministry of the Environment.

Reservations
The screening methods described can only be used for indication purposes and cannot replace actual laboratory analyses performed according to current standards. In cases where the screening analysis results may give rise to third-party economic costs, verification by an accredited laboratory is therefore recommended. Information on the applications of chromium(VI), PBDEs and PBBs in electrical products reflect the knowledge available to the authors at the time of writing, but the possibility that some applications of the substances have not been included in the description cannot be excluded.