| When designing your products it is important that you consider your use of materials carefully. The following points can be addressed. Reduce the Amount of Materials Used Reducing the amount of materials used in production not only reduces environmental impact, but also reduces costs. Minimise your use of resources, for example by: Defining realistic requirements for stiffness and strengthOptimising part dimensions (eg. using finite element analysis)Considering alternatives to thick-walled sections, such as ribbed structures, bosses, supports and hollow structures using gas-assisted injection moulding.Reduce the Number of Different Materials Used Minimising the number of different materials used in a product can reduce manufacturing costs (through economies of scale) as well as increase the potential for materials recycling at end of life. Use Materials with Less Impact The environmental impact of your product can be reduced by using materials that: use less energy in refining and extraction; are less toxic; are more abundant and/or; are more easily recycled. Different materials display these properties to different degrees and you may find that you need to make trade-offs. For example, metals are highly recyclable compared to plastics, but are heavier and require more energy to produce and transport. When designing Electronic and Electrical Equipment (EEE) you should take the following general points into consideration: Metals Consider using metals to help meet recyclability requirements under WEEE. Costs can be reduced by making components and sub-assemblies thinner, smaller, lighter or less numerous.Be aware that the recycling of some metals can be hindered by the occurrence of impurities. Try to find alternative solutions for incompatible combinations, or design your product in a way that eases separation of the pure metals.Plastics Choose plastics that can be recycled: thermoplastics (e.g. PET, PS) and polyolefines (e.g. HDPE, LDPE and PP) can be, but thermosetting plastics cannot.Try to use the same plastic polymer throughout your product. If this is not possible, you should select combinations of polymers which are compatible for recycling.Any plastics should be marked with the material category and date of manufacture to optimise recycling opportunities.Try to avoid using PVC and other halogen containing polymers. PVC is being phased out of the design of many products because of concerns regarding health.Consider the design of the injection moulding process. Some design features (eg sharp corners) and process steps (eg heating profiles) can degrade polymers and reduce the quality of the plastic for recycling.Hazardous substances Many EEE products are subject to the RoHS Directive. Producers should use lead-free solder and eliminate the use of brominated flame retardants.In general, it is advisable to avoid all hazardous materials. Where this is not practical, the materials should be clearly marked and easy to separate. For example, group any hazardous materials or components in one area of a printed circuit board, and if feasible design for easy snap off.Some organisations have lists of undesired substances. Consider if your product contains some of these, and if it does, can the use of the substance be avoided?Renewables Investigate the use of materials from renewable or sustainable resources. Make Use of Recycled Materials Wherever possible try and use recycled materials. Many are no longer inferior in aesthetic or mechanical properties. The implementation of the WEEE Directive will mean that recycled materials should be more widely available in the future. Creating more demand for recyclate will also further reduce its cost. Further Sources of Support The EcoSMEs LCA tool, eVerdEE can help you to make product-comparisons based on your choice of materials. The Danish eco-design guide for EEE provides useful guidance on the relative properties of different materials. The online dismantling exercise, developed by Envirowise outlines issues regarding material choice in more detail. Envirowise also offer free sustainable design reviews for SMEs. These can be booked by phoning the Environment and Energy Helpline on 0800 585794 and asking for a DesignTrack visit. | 
