When people discard their waste electrical and electronic equipment (WEEE), different materials become available for recycling and reuse. In terms of volume, the most important of these materials are steel, aluminium and copper as well as plastics. Recovering these and some other metals is rather uncomplicated. Valorizing the plastic fraction, on the other hand, is more challenging because the different plastics need to be sorted by type.
Another main challenge to WEEE plastic recycling that have to be addressed is they often contain additives, some of which are hazardous to human health and the environment. The most problematic plastic additives are Brominated Flame Retardants (BFRs) and additives based on heavy metals. Plastics containing such hazardous substances need to be removed and disposed of in appropriate ways.
The most common plastic in WEEE is the ABS (acrylonitrile butadiene styrene), representing over 20% of the total materials. In addition, the actual share of ABS is higher because the second major engineering plastic is a combination of ABS and PC (polycarbonate), also known as ABS-PC which are used in mobile phone bodies. The other commodity plastics identified include PP (polypropylene) and PS (polystyrene) etc.
Some plastics for instance are used for very specific purposes and can be identified because of this. A transparent plastic sheet obtained through the dismantling of a flat screen, for example, is almost certainly made from PMMA plastic. Other plastics are commonly used in some devices, but rarely in others, and some can be found in almost any device.
WEEE plastic recycling can reduce dependence on landfill, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions. Plastic recycling rates lag behind those of other recoverable materials, such as aluminium, glass and paper. Almost all plastic is non-biodegradable and without recycling, spreads across the environment where it causes plastic pollution where it enters the oceans, damaging oceanic ecosystem and forming ocean garbage patches.
The recovery and recycling of WEEE plastics has important environmental benefits both through the substitution of virgin plastics in products and because higher recycling rates result in less plastic waste ending up in the environment and in lower carbon dioxide emissions.
