Rapid identification of polystyrene foam wastes containing hexabromocyclododecane or its alternative polymeric brominated flame retardant by X-ray fluorescence spectroscopy.

The brominated flame retardant hexabromocyclododecane (HBCDD) was added to Annex A of the list of persistent organic pollutants (POPs) of the Stockholm Convention. Thus, production and use of HBCDD will be banned, and the recycling of HBCDD-containing foam waste will be restricted. In reaction a special polymeric brominated flame retardant (PolyFR) was developed to replace HBCDD in expanded and extruded polystyrene foams for building and construction applications. A decision has to be made at some future time whether expanded and extruded polystyrene foam waste is to be subjected to incineration (with HBCDD) or to recycling (without HBCDD). Therefore, an appropriate and rapid field method is required to distinguish between foams containing HBCDD and foams free from HBCDD. Here we present a screening method for identifying HBCDD containing expanded and extruded polystyrene foams. The test principle is based on the fact that PolyFR (a brominated polymeric macromolecule) is not extractable whereas HBCDD (a low molecular weight substance) is extractable. Following rapid extraction of HBCDD the brominated flame retardant is identified and quantified via bromine analysis using a handheld X-ray fluorescence instrument. The method was applied successfully to 27 expanded and extruded polystyrene foam samples (foams and extruded polystyrene foam raw materials), which were provided without any information about the applied flame retardant. The presence of HBCDD was confirmed for all HBCDD-positive samples in the test. A robustness test revealed a high degree of correctness and a high repeatability for the test system: samples containing HBCDD and HBCDD-free samples were identified correctly with relative standard deviations of quantitative results below 14%. Moreover, X-ray fluorescence spectroscopy test results agree well with HBCDD determinations performed in a laboratory with a gas chromatograph coupled to a flame ionisation detector.

Emission of perfluoroalkyl carboxylic acids (PFCA) from heated surfaces made of polytetrafluoroethylene (PTFE) applied in food contact materials and consumer products.

Polytetrafluoroethylene (PTFE) has been widely discussed as a source of perfluorooctanoic acid (PFOA), which has been used in the production of fluoropolymers. PTFE may also contain unintended perfluoroalkyl carboxylic acids (PFCAs) caused by thermolysis of PTFE, which has been observed at temperatures above 300°C. Common PTFE coated food contact materials and consumer goods are operated at temperatures above 200°C. However, knowledge on possible emissions of PFCAs is limited. Therefore, it was the aim of this study to investigate and evaluate the emission of PFCAs from PTFE coated products with both, normal use and overheating scenarios. Four pans, claimed to be PFOA free, and nine consumer products were investigated. At normal use conditions (<230°C), emissions from PTFE surfaces were trapped for 1h. Overheating scenarios (>260°C) recorded emissions during a 30min heating of empty pans on a stove. Emissions were analyzed by LC-ESI-MS. Results indicate the emission of PFCAs, whereas no perfluorinated sulfonic acids were traced. At normal use conditions total emissions of PFCAs accounted for 4.75ng per hour. Overheated pans, however, released far higher amounts with up to 12190ng PFCAs per hour at 370°C. Dominating contributors where PFBA and PFOA at normal use and PFBA and PFPeA during overheating. Temperature seems to be the main factor controlling the emission of PFCAs. A worst case estimation of human exposure revealed that emissions of PFCAs from heated PTFE surfaces would be far below the TDI of 1500ng PFOA per kg body weight.

Impact of industrial production and packaging processes on the concentration of per- and polyfluorinated compounds in milk and dairy products.

Perfluorinated alkylated compounds (PFAA) have been identified in milk and dairy products at sub ppb levels, however, knowledge on the impact of industrial milk processing on PFAA levels is rare. This study examined industrial milk processing first by analytical screening of products of a cooperating dairy, which varied in kind and number of processing steps. Second, amounts of PFAA in raw milk, cream, skim milk, butter milk, and butter were mass balanced in industrial production. For migration testing, unpacked butter was sampled from the production and exposed to original packaging at 5 °C for 45 days. Screening identified dairy products with high fat contents to bear higher loads of PFAA. The mass balance of butter production revealed a significant impact of phase separation processes on concentrations in fat rich and aqueous phases. Storage of butter in packaging coated with a fluorinated polymer increased butter levels of both PFAA and FTOH.

Investigation into the sorption of nitroglycerin and diazepam into PVC tubes and alternative tube materials during application.

Plastic bags and tubes are increasingly used for the storage and application of pharmaceutical formulations. The most common polymer material for drug application sets is plasticized poly(vinylchloride) (PVC). During application of pharmaceutical drug solution through PVC tubes, the polymer and the contact media interact which leads to leaching out of polymer additives or sorption of ingredients of the drug solution. Whereas the discussion of leaching of plasticizers is focussed on the toxicological properties of a drug packaging system, the sorption of drug formulation compounds has an influence on the dosage of the active pharmaceutical ingredient resulting in a reduced drug delivery to the patient. Therefore sorption has an influence on the effectiveness and success of the therapy. Within the study, the concentration profiles of nitroglycerin and diazepam solutions were determined after pumping the solutions through infusion administration sets. The study includes plasticized PVC tubes with different plasticizers (DEHP, DEHA, DEHT, TEHTM, DINCH, poly adipate), PVC (DEHP) tubes with different shore hardness as well as alternative polymer materials like EVA, TPE, PUR, silicone, LDPE and PP. From the experimental concentration curves it could be shown, that in the first minutes of the application of the drug solution the sorption of the active compound is at its maximum, resulting in the lowest concentration in the applied pharmaceutical solution. For a PVC tube with DEHP as plasticizer and a shore hardness of 80 only about 57% of the initial nitroglycerin concentration in the solution is applied to the patient in the first minutes of the application. For PVC tube (DEHP, shore 80) the experimental data were simulated using mathematical diffusion models. The concentration profiles during application could be well simulated using the partition coefficient K=50 (nitroglycerin) and K=300 (diazepam), respectively. However, the experimental results indicate, that the sorption of nitroglycerin into the PVC tube alters the diffusion behaviour of the polymer over flow time, which results in an increase of the diffusion coefficient during application. On the other hand, the other investigated alternative tube materials like PE or PP show a significantly lower sorption compared to PVC plasticizer systems. Due to the fact that the amount of sorption is varying over time, the concentration of the active pharmaceutical compound in the solution after passing the infusion administration set is not constant which makes the application of a constant concentration of a certain active ingredient to the patient very difficult. The simulated partition and diffusion coefficients for given PVC(DEHP) tubes were therefore used to simulate the initial concentrations profile of the feeding drug solution to assure a constant concentration flow profile after passing the administration set. The proposed methodology of this study represents a straight forward approach for the assessment of the drug sorption in dynamic flow systems based on experimental data as well as mathematical diffusion modelling. From the results a non-constant initial concentration profile for the active ingredient in a pharmaceutical drug solution can be established in order to compensate the loss of the pharmaceutical compound by sorption during infusion.

Exposure of an adult population to perfluorinated substances using duplicate diet portions and biomonitoring data.

Because dietary intake is supposed to be an important route of human exposure we quantified the dietary intake of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), perfluorohexanoate (PFHxA), and perfluorooctane sulfonamide (PFOSA) using 214 duplicate diet samples. The study was carried out with a study population of 15 female and 16 male healthy subjects aged 16-45 years. The participants collected daily duplicate diet samples over seven consecutive days in 2005. Duplicate samples were homogenized and their ultrasonic extracts were cleaned up by SPE and subjected to HPLC-ESI-MS/MS. In addition, individual intakes were estimated based on blood levels of PFOS and PFOA using a pharmacokinetic model. Blood samples were collected once during the sampling period. The median (90th percentile) daily dietary intake of PFOS and PFOA was 1.4 ng/kg b.w. (3.8 ng/kg b.w.) and 2.9 ng/kg b.w. (8.4 ng/kg b.w.), respectively. PFHxS and PFHxA could be detected only in some samples above detection limit with median (maximum) daily intakes of 2.0 ng/kg b.w. (4.0 ng/kg b.w.) and 4.3 ng/kg b.w. (9.2 ng/kg b.w.), respectively. Because PFOSA could not be detected above the limit of detection of 0.2 ng/g f.w. this indirect route of exposure seems to be of less significance. Overall, the results of this study demonstrate that the German population is exposed to PFOS and PFOA, but the median dietary intake did not reach the recommended tolerable daily intake by far. Biomonitoring data predict an exposure in a comparable range. We suppose that, normally, food intake is the main source of exposure of the general population to PFOS and PFOA.

Intake of phthalates and di(2-ethylhexyl)adipate: results of the Integrated Exposure Assessment Survey based on duplicate diet samples and biomonitoring data.

Phthalates are ubiquitous environmental chemicals with potential detrimental health effects. The purpose of our study was to quantify dietary intake of phthalates and of DEHA (Di-ethylhexyl adipate) using duplicate diet samples and to compare these data with the calculated data based on urinary levels of primary and secondary phthalate metabolites. 27 female and 23 male healthy subjects aged 14-60 years collected daily duplicate diet samples over 7 consecutive days. Overall, 11 phthalates were measured in the duplicates by GC/MS and LC/MS methods. Urinary levels of primary and secondary phthalate metabolites are also available. The median (95th percentile) daily intake via food was 2.4 (4.0) microg/kg b.w. (Di-2-ethylhexyl phthalate, DEHP), 0.3 (1.4) microg/kg b.w. (Di-n-butyl phthalate, DnBP), 0.6 (2.1) microg/kg b.w. (Di-isobutyl phthalate, DiBP) and 0.7 (2.2) microg/kg b.w. for DEHA. MEPH (Mono-2-ethylhexyl phthalate) was detectable only in minor concentrations in the samples, thus conversion of DEHP to MEHP and dietary intake of MEHP were negligible. When comparing back-calculated intake data of the DEHP metabolites with dietary DEHP intake from the day before significant correlations were observed for most of the metabolites. No correlation was found for DnBP and only a weak but significant correlation for DiBP. The median and 95th percentile daily dietary intake of all target analytes did not exceed the recommended tolerable daily intake. Our data indicated that food was the predominant intake source of DEHP, whilst other sources considerably contributed to the daily intake of DnBP and DiBP in an adult population.

Characterisation of polymer fractions from waste electrical and electronic equipment (WEEE) and implications for waste management.

There is an increasing interest in the end-of-life management of polymers present in waste electrical and electronic equipment (WEEE). This is mainly due to high recycling and recovery quotas set by the European WEEE directive, which can only be fulfilled by including the plastic fraction in recycling and recovery approaches. Previous studies identified a high material diversity and various contaminants in WEEE plastics, including heavy metals, polybrominated biphenyls (PBB), diphenyl ethers (PBDE), as well as polybrominated dibenzodioxins and dibenzofurans (PBDD/F). These substances are regulated by European directives that limit their levels in marketable products. Consequently, both material diversity and contaminants are strong arguments against material recycling and point to hazardous waste treatment. However, recent developments in the production of flame retardants and electrical and electronic goods aimed to reduce contaminants and material diversity. Thus, the present study summarises updated contaminant levels of plastic fractions of European WEEE, as well as data on materials in waste housing polymers. Material characterisation revealed housing fractions to be interesting sources for polymer recycling, which however has to implement potent material separation and/or bromine elimination techniques. With respect to contaminants, our data indicate an effective phase-out of PBB, but still high levels of PBDE and PBDD/F are found. Sources and implications for the material recycling and thermal recovery approaches are discussed in detail.