Identification of impurities of phosphate and brominated flame retardants

In the last years, new flame retardants (FRs) have been identified for the first time in products and in environmental samples by using mainly liquid chromatography coupled to high resolution mass spectrometry. For example, 2,2-bis(chloromethyl)propane-1,3-diyl-tetrakis(2-chloroethyl)bis(phosphate), known commercially as “V6”,1 or a triazine-based flame retardant [2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, TTBP-TAZ]2 were recently reported. Not only FRs, but also their byproducts, impurities or degradation products have been very recently identified, such as those derived from tetrabromobisphenol-A (TBBP-A) or tetrabromobisphenol-S.3,4 The persistency and toxicity of these impurities or related compounds, as well as their presence in the environment is still largely unknown. We present and discuss here an overview of our results on the investigations of impurities and degradation products of FRs, namely from TTBP-TAZ2, RDP5, TBBPA and TBBPA-based products6 and the impurity diphenyl phosphate (DPHP) that derives from a variety of phosphorus flame retardants (PFRs

Identification of impurities of phosphate and brominated flame retardants

In the last years, new flame retardants (FRs) have been identified for the first time in products and in environmental samples by using mainly liquid chromatography coupled to high resolution mass spectrometry. For example, 2,2-bis(chloromethyl)propane-1,3-diyl-tetrakis(2-chloroethyl)bis(phosphate), known commercially as “V6”,1 or a triazine-based flame retardant [2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, TTBP-TAZ]2 were recently reported. Not only FRs, but also their byproducts, impurities or degradation products have been very recently identified, such as those derived from tetrabromobisphenol-A (TBBP-A) or tetrabromobisphenol-S.3,4 The persistency and toxicity of these impurities or related compounds, as well as their presence in the environment is still largely unknown. We present and discuss here an overview of our results on the investigations of impurities and degradation products of FRs, namely from TTBP-TAZ2, RDP5, TBBPA and TBBPA-based products6 and the impurity diphenyl phosphate (DPHP) that derives from a variety of phosphorus flame retardants (PFRs

Synthetic musks in fish and other aquatic organisms

Musk compounds are widely spread environmental pollutants. Musk compounds were found in aquatic organisms from the North Sea, in rivers, lakes and estuaries in Canada, Czech Republic, Germany, Italy, Luxembourg, Japan, Norway, Switzerland, Sweden, and The Netherlands. Two nitro musks, musk xylene (MX) and musk ketone (MK), and two polycyclic musks (HHCB and AHTN) were the major musk compounds determined and observed in freshwater as well as in marine organisms. The main source of nitro and polycyclic musk residues in aquatic organisms are effluents from sewage treatment plants (STPs). The presence of synthetic musk compounds in biota can, therefore, be used as an indicator of the exposure of biota to STP effluents. Synthetic musk compounds have mainly been determined in fish, but some data are also available for mussels and shrimps. In addition, MX was found in eggs of coastal bird species, and HHCB and AHTN were identified in otters. The concentrations of HHCB and AHTN in freshwater organisms from Europe are one to two orders of magnitude higher than MX and MK, and comparable to levels of PCBs in fish. Indications were found that several fish species such as eel (Anguila anguila) could metabolise HHCB and AHTN, and that food chain transfer of these musk compounds from prey fish (e.g. roach) to carnivore fish (pike-perch) occurs. Time trend data for MX and MK in eel from the river Elbe (Germany) showed that for some locations a decline in the concentrations from 1994 to 1999 occurred, probably due to the restriction of the use of MX in Germany since 1993. Similar results were observed for MX in eel from the river Rhine. Nitro musks and polycyclic musks were found in fish samples (e.g. trout, herring, mussels, tuna and mackerel) collected at food markets. In some samples (trout and shrimp) the concentrations of MX and MK were similar to the concentrations of PCBs, while in other samples (e.g. halibut and mussels) the concentrations of MX and MK are one to two orders of magnitude lower than those of PCBs. In general, the highest concentrations of MX were found in trout, and in some tuna samples rather high concentrations of MK were found

Life cycle assessment of flame retardants in an electronics application

Purpose: Flame retardants are added to plastics and textiles to save lives. However, certain brominated flame retardants (BFRs) form an environmental hazard and should be replaced by less harmful alternatives. In the recently completed European research project ENFIRO, we examined which alternatives are most suitable from a technical and environmental perspective. This study describes the LCA comparison of BFRs and halogen-free flame retardants (HFFRs) in an electronics product, in order to compare their environmental impacts over the whole life cycle and identify where in the life cycle the main impacts occur. Methods: This cradle to grave LCA used the complete life cycle of a laptop computer as the functional unit. Specific attention was paid to often neglected aspects, including emissions of flame retardants in all life cycle phases, emissions during accidental fire and improper waste treatment. New characterization factors for toxicity of flame retardants were calculated using USES-LCA2 and included in the impact assessment. Results and discussion: The largest differences in impact were found to occur in the waste phase due to an increased dioxin emission formed out of BFRs during improper waste treatment. Minor human toxicity and ecotoxicity impacts of FRs are present due to volatilization in the use phase. FR emissions during accidental fire vary with the FR’s mode of action (active in the gaseous or solid phase). The BFR scenario has a higher impact than the HFFR scenario due to a higher rate of smoke formation and a higher terrestrial ecotoxicity score. In most phases of the life cycle of FRs, fossil energy use related impact categories dominate the LCA score, i.e. climate change, fossil depletion, and particulate matter formation. Over the full life cycle, the BFR scenario has a slightly higher environmental impact than the HFFR scenario, mainly through the contribution of human toxicity in the waste phase. Conclusions: The study shows that for improvements of the life cycle environmental performance of FRs, the waste treatment phase is critical. Export and improper treatment of WEEE have the highest impact of all waste treatment options for both the BFR and HFFR scenarios, and efforts should be intensified to reduce the amount of WEEE ending up in this scenario. The study further shows that processes which are often ignored in LCA can give relevant insights into the environmental performance of a product. It is therefore recommended to broaden the scope and system boundaries of future LCA studies to include unofficial scenario options (specifically in the end-of-life phase) to provide a more complete description of the full environmental impact of a product’s life cycle and thereby contribute to relevant discussions in society and policy

Analysis of recycled rubber:Development of an analytical method and determination of polycyclic aromatic hydrocarbons and heterocyclic aromatic compounds in rubber matrices

Recycled crumb rubber (CR) is rich in compounds with unrecognized toxic potency; this study aims at the development of an analytical method that would allow identification and quantification of a very wide range of organic compounds extractable from the complex rubber matrix. The analytical set-up includes target analysis of polycyclic aromatic hydrocarbons (PAHs) and methyl-PAHs and suspect screening of raw extracts to tentatively identify primary organic compounds present, but not included in the standard target analysis of recycled rubber, followed by analytical method development and target analysis of identified compounds. Analyzed samples included weathered and new CR originating from football turf granulates, rubber mats, and end-of-life car tires (ELTs). The developed analytical method involves sonication extraction, followed by solid phase extraction (SPE) fractionation that enables simple and efficient separation of analytes with broad polarity scale. The application of SPE fractionation resolves coelution problems and simplifies the chromatograms. This analytical approach allowed to identify and quantify 46 sample specific compounds, including several heterocyclic PAHs like 2-methylthiobenzothiazole, benzonapthothiophenes, benzonaphthofuranes and aromatic amines like diphenylamine and N-phenyl-2-naphthylamine, which to our knowledge were not determined before. The PAHs concentrations determined in CR tiles purchased in Dutch and Spanish shops exceed the EU limits for articles marketed for use by the public. Furthermore, sets of methylated PAHs, dibenzothiazoles and aromatic amines were identified and quantified, and several other compounds were tentatively identified. The obtained results stress the need for expanding the list of target compounds analyzed in CR and the need for longitudinal studies on weathering processes taking place in CRS

Chlorinated paraffins and tris (1-chloro-2-propyl) phosphate in spray polyurethane foams – A source for indoor exposure?

In this study, we investigated chemical additives present in new and used spray polyurethane foams (SPFs) and assessed the dermal transfer through direct contact. This first study shows that cured do-it-yourself spray one-component SPFs (OCFs) often contain chlorinated paraffins (C14-C37), and tris (1-chloro-2-propyl) phosphate (TCIPP), ranging 0.2–50%, and 0.9–30% w/w, respectively. Six OCFs contained CP levels ranging 22–50% w/w, whereas nine OCFs used for similar applications only contained CP levels ranging 2–17% w/w. It is unclear if the combination CPs/TCIPP is meant to improve the flame retardancy of products, and could suggest an unnecessary use of high CPs/TCIPP concentrations in OCFs. The two-component SPFs (TCFs) contained only TCIPP with levels ranging from 7.0% to 9.0%. The CPs and TCIPP were easily transferred from cured OCFs to the hands. Levels up to 590 µg per hand for CPs and up to 2.7 µg per hand for TCIPP were found. After end-of-life, it is challenging to recycle used SPFs. They may, therefore, end up at landfills where the TCIPP/CPs may leach into the environment. Therefore, further investigation is needed to assess potential exposure risks associated with general and occupational use, and the impact of landfill leaching on the environment

Effects of environmental pollutants on calcium release and uptake by rat cortical microsomes

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Metabolite alterations in zebrafish embryos exposed to hydroxylated polybrominated diphenyl ethers

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are formed by metabolism from the flame retardants polybrominated diphenyl ethers (PBDEs). In the aquatic environment, they are also produced naturally. OH-PBDEs are known for their potential to disrupt energy metabolism, the endocrine system, and the nervous system. This is the first study focusing on the effects of OH-PBDEs at the metabolite level in vivo. The aim of the current study was to investigate the metabolic effects of exposure to OH-PBDEs using metabolomics, and to identify potential biomarker(s) for energy disruption of OH-PBDEs. Zebrafish (Danio rerio) embryos were exposed to two different concentrations of 6-OH-BDE47 and 6-OH-BDE85 and a mixture of these two compounds. In total, 342 metabolites were annotated and 79 metabolites were affected in at least one exposure. Several affected metabolites, e.g. succinic acid, glutamic acid, glutamine, tyrosine, tryptophan, adenine, and several fatty acids, could be connected to known toxic mechanisms of OH-PBDEs. Several phospholipids were strongly up-regulated with up to a six-fold increase after exposure to 6-OH-BDE47, a scarcely described effect of OH-PBDEs. Based on the observed metabolic effects, a possible connection between disruption of the energy metabolism, neurotoxicity and potential immunotoxicity of OH-PBDEs was suggested. Single compound exposures to 6-OH-BDE47 and 6-OH-BDE85 showed little overlap in the affected metabolites. This shows that compounds of similar chemical structure can induce different metabolic effects, possibly relating to their different toxic mechanisms. There were inter-concentration differences in the metabolic profiles, indicating that the metabolic effects were concentration dependent. After exposure to the mixture of 6-OH-BDE47 and 6-OH-BDE85, a new metabolic profile distinct from the profiles obtained from the single compounds was observed. Succinic acid was up-regulated at the highest, but still environmentally relevant, concentration of 6-OH-BDE47, 6-OH-BDE85, and the mixture. Therefore, succinic acid is suggested as a potential biomarker for energy disruption of OH-PBDEs

A Rapid Screening Method for the Detection of Additives in Electronics and Plastic Consumer Products Using AP-MALDI-qTOF-MS

A novel method was developed and optimized for the fast-screening analysis of additives in electronics and plastic consumer products using atmospheric pressure matrix-assisted laser desorption ionization (AP-MALDI) coupled with a high-resolution quadrupole time-of-flight (qTOF) mass spectrometer (MS). To simplify sample preparation and increase sample throughput, an innovative 48 well graphene nanoplatelets (GNP) doped AP-MALDI target plate was developed. The GNP incorporated in the target plate fulfilled the role of the MALDI matrix and, therefore, sample extracts could be directly transferred to the AP-MALDI 48 well target plate and analyzed without a subsequent matrix addition. The homogeneously dispersed and immobilized GNP target plates also provided increased signal intensity and reproducibility. Furthermore, analytical standards of various plastic additives and plastic products with known concentrations of additives were studied to assess the AP-MALDI ionization mechanisms and method capability. The analysis time was 15 s per measurement using an automated sequence. The GNP-doped target plates exhibited high desorption/ionization of low molecular weight molecules (<1000 Da) and can be used in both positive and negative ionization modes. The AP-MALDI-qTOF-MS method was applied to screen for additives in various electronics and plastic consumer products. Suspect screening was performed using a database containing 1366 compounds. A total of 56 additives including antioxidants, flame retardants, plasticizers, UV-stabilizers, and UV-filters were identified (confidence level 4). Identification of certain plastic additives in plastic children’s toys may indicate that they are recycled from waste electronic and electronic equipment (WEEE)

Migration of hazardous contaminants from WEEE contaminated polymeric toy material by mouthing

This study evaluated the migration of brominated flame retardants (BFRs), phosphate flame retardants (PFRs), bisphenols (BPA, BPF), and phthalate ester-based plasticizers from recycled polymeric toy material, containing waste electrical and electronic equipment (WEEE), in artificial saliva simulating 1 h of mouthing. In total 12 parts of 9 different toys were tested in triplicate after confirming WEEE specific contamination. Up to 11 contaminants were detected in saliva from one toy sample. The highest migration rate up to 128 ng/(cm2 x h) was found for BPA followed by bis(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DIBP) with migration rates up to 25.5 and 8.27 ng/(cm2 x h), respectively. In addition to DecaBDE, which was detected in 3 saliva samples at migration rates between 0.09 and 0.31 ng/(cm2 x h), the decaBDE replacements 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ), decabromodiphenyl ethane (DBDPE), resorcinol bis(diphenyl phosphate) (RDP), and hexabromocyclododecane (HBCDD) were detected as well with comparable migration rates. 2,4,6-tribromphenol (246-TBP) reached migration rates up to 1.15 ng/(cm2 x h) in correspondence to the presence of TTBP-TAZ. Tetrabromobisphenol A (TBBPA), BPA, 246-TBP, DEHP, DIBP and triphenyl phosphate (TPHP) were predominantly observed in saliva with a detection frequency between 50 and 75%. Daily intake (DI) values were calculated for relevant analytes and compared to tolerable daily intake (TDI) values. The highest DI values of 72.4, 14.3, 5.74, 2.28 and 2.09 ng/(kg BW x day), were obtained for BPA, DEHP, DIBP, TBBPA, and TPHP, respectively. None of them exceed the TDI value or respective reference dose (RfD)