Towards a generic procedure for the detection of relevant contaminants from waste electric and electronic equipment (WEEE) in plastic food-contact materials: a review and selection of key parameters

Abstract

Recently, traces of brominated flame retardants (BFRs) have been detected in black plastic foodcontact materials (FCMs), indicating the presence of recycled plastics, mainly coming from waste electric and electronic equipment (WEEE) as BFRs are one of the main additives in electric applications. In order to evaluate efficiently and preliminary in situ the presence of WEEE in plastic FCMs, a generic procedure for the evaluation of WEEE presence in plastic FCMs by using defined parameters having each an associated importance level has been proposed. This can be achieved by combining parameters like overall bromine (Br) and antimony (Sb) content; additive and reactive BFR, rare earth element (REE) and WEEE-relevant elemental content and additionally polymer purity. In most of the cases, the WEEE contamination could be confirmed by combining X-ray fluorescence (XRF) spectrometry and thermal desorption/pyrolysis gas chromatography-mass spectrometry (GC-MS) at first. The Sb and REE content did not give a full confirmation as to the source of contamination, however for Sb the opposite counts: Sb was joined with elevated Br signals. Therefore, Br at first followed by Sb were used as WEEE precursors as both elements are used as synergetic flame-retardant systems. WEEE-specific REEs could be used for small WEEE (sWEEE) confirmation; however, this parameter should be interpreted with care. The polymer purity by Fourier-transform infrared spectrometer (FTIR) and pyrolysis GC-MS in many cases could not confirm WEEE-specific contamination; however, it can be used for purity measurements and for the suspicion of the usage of recycled fractions (WEEE and non-WEEE) as a third-line confirmation. To the best of our knowledge, the addition of WEEE waste to plastic FCMs is illegal; however, due to lack on screening mechanisms, there is still the breakthrough of such articles onto the market, and, therefore, our generic procedure enables the quick and effective screening of suspicious samples. ARTICLE HISTORY

Recycling Plastics from WEEE: A Review of the Environmental and Human Health Challenges Associated with Brominated Flame Retardants

“…The study confirms the indication that black polymer FCAs manufactured using recycled WEEE plastic circulate in the European market. Two years later, the same author published in [ 47 ] a study linked to that of 2015, aimed at proposing a method based on levels of significance for an efficient in situ assessment of the presence of WEEE plastics in FCA plastics by determining Br and Sb (level 1), BFRs (level 2) and WEEE-related elements and additionally the purity of the polymers (level 3).…”

Rare earth elements in plastics

“…The presence of REEs in recycled electrical and electronic plastic (but evidently not in new electronic plastic) is likely to arise through contamination of the material from traces of non-plastic components as shreds and dust (Marra et al, 2018). Many REEs are particularly concentrated in small devices such hard drives, phones and iPods (Buechler et al, 2020), with specific uses including Ce, Dy, La and Y in LEDs, Ce, La and Y in fluorescent powders, Ce, La, Nd and Pr in rechargeable batteries and Nd and Pr in magnets (Puype et al, 2017). In contrast, Er and Tm appear to be encountered least in e-waste, with analysis of a range of pulverised and digested electronic devices and components failing to return detectable or quantifiable concentrations of these REEs (Buechler et al, 2020).…”

“…The most common markers of electrical and electronic plastic that are often evident in recycled products are various brominated flame retardants, with or without the flame suppression synergist, Sb2O3 (Turner, 2018;Filella et al, 2020). However, Puype and co-workers (Puype et al, 2015;Puype et al, 2017;Guzzonato et al, 2019) have proposed that rare earth elements (REEs) may also be used as a proxy for recycled electrical and electronic plastic and for more precise information on the origin of the original product. REEs, comprising the fifteen lanthanide elements (La through to Lu), plus Sc and Y, have a variety of critical applications in modern electronic equipment because of their magnetic, phosphorescent and electrochemical properties (Balaram, 2019).…”

Evaluation of the presence of potential hazardous substances from plastic and textile fibre recycling

“…For instance, brominated and phosphorous flame retardants and phthalates have been found in children toys from recycling (Chen et al, 2009: Ionas et al, 2014: Lee et al, 2014. Flame retardants have also been measured in samples of black plastic FCMs and household products from the European market (Samsonek and Puype, 2013: Puype et al, 2015: Puype et al, 2017. Flame retardants are commonly divided into four groups in accordance to the main chemical constituent used, i.e.…”