POPs are organic chemicals that persist in the environment, build up in the food chain, and pose a risk to human health. Polybrominated diphenyl ethers (PBDEs), used as flame retardants in some plastic components, are classed as POPs. Although they have been regulated and restricted in manufacturing since 2008, products produced before this may have contained PBDEs but are only now arising in the waste stream.
In the UK, contaminated WEEE plastics must be treated to destroy the POPs chemicals – they cannot be recycled. So it is important to have a clear picture of the presence of these substances in WEEE and how they affect management of the waste stream.
First, using a technique called X-ray fluorescence, the study tested thousands of WEEE samples from nine UK processing facilities for the presence of brominated flame retardants. Secondly, they tested a subset of WEEE product categories for brominated compounds present in the plastics. This second phase used a technique called gas chromatography mass spectrometry (GCMS) analysis.
The testing found that POPs-PBDEs exceeded permitted levels in specific components: printed circuit boards, cables, cathode ray tube displays, flat panel displays, small mixed WEEE, and office equipment. These WEEE material types were subsequently classified as containing POPs and hazardous waste – and the Environment Agency has updated its existing guidance accordingly.
Further work is needed in a number of areas:
i) Fridge plastic – to assess the POPs and hazardous content of this plastic stream to ensure correct classification of waste, and ensure safe treatment of fridge waste.
ii) Bromine separation of WEEE plastics – to evaluate how well current processes separate potential POPs-containing plastics, and to provide a benchmark for future separation processes.
iii) Printer cartridges – to test for POPs and other hazardous substances.
iv) Alternative management options for POPs-containing plastic fraction – to establish feasibility of other advanced thermal treatment technologies for this material, such as gasification or pyrolysis.
v) Brominated compound extraction techniques – to optimise and benchmark extraction techniques in order to avoid under-reporting of data.
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Industry Council for Electronic Equipment Recycling (ICER) & Water Research Centre (WRC), March 2020. Summary, 9 pages; full report, 330 pages.Download