Bis 2-ethylhexyl Tetrabromophthalate Research Articles

Novel and legacy brominated flame retardants in human breast milk and house dust from Denmark

A suite of novel brominated flame retardants (NBFRs), hexabromocyclododecanes (HBCDDs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus were measured in matched samples of house dust (n = 47) and human breast milk (n = 40) from Denmark sampled in 2007, i.e., shortly after PBDE restrictions were implemented in Europe providing a valuable reference point. The most abundant BFR in breast milk was BDE-153 with a median concentration of 0.79 ng/g lipid followed by BDE-47 (median: 0.61 ng/g lipid) and BDE-209 (median: 0.53 ng/g lipid). Levels of bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP) were comparable (median: 0.78 ng/g lipid); however, they were based on fewer samples. α-HBCDD was the most abundant HBCDD in breast milk (median: 0.24 ng/g lipid) and detected in all samples. The house dust samples were dominated by BDE-209 (median: 432 ng/g) and γ-HBCDD (median: 177 ng/g); among the NBFRs, the highest levels were found for decabromodiphenyl ethane (DBDPE) (median: 86.2 ng/g) and BEH-TEBP (median: 26.7 ng/g). BDE-28, 47 and 153 were significantly correlated between breast milk and serum (rs = 0.73-0.81, P < 0.0001); however, this was not the case for any of the NBFRs. Intake estimates for a 3-month-old infant indicated that for most of the flame retardants, breast milk was by far the dominant route of exposure, whereas dust only contributed substantially for BDE-209, γ-HBCDD, and to some extent α-HBCDD. This study is the first to report on human exposure to NBFRs in Denmark and shows that internal exposure levels of NBFRs were similar to those of most PBDEs already at the time of PBDE restrictions.

Trends in flame retardant levels in upholstered furniture and children's consumer products after regulatory action in California

In 2013, California revised its upholstered furniture flammability standard TB 117–2013 to improve fire safety without the need for flame retardant (FR) chemicals. Subsequent legislation (SB 1019) required disclosure of FR content. In 2020 California expanded restriction on FR chemicals to include juvenile products and upholstered furniture (AB 2998). To monitor trends in FR use, and assess the effectiveness of the new regulations, we analyzed 346 samples from upholstered furniture (n = 270) and children's consumer products (n = 76), collected pre- and post-regulatory intervention for added FR chemicals (i.e., ∑FR > 1000 mg/kg). Upholstered furniture samples, collected from products before enactment of the new regulations, had a median FR concentration of 41,600 mg/kg (range: 1360–92,900 mg/kg), with 100% of the foam samples and 13.7% of the textile samples containing ∑FR > 1000 mg/kg. Firemaster formulations (FM 550 and FM 600), a mixture of triphenyl phosphate (TPHP), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TEBP) and a mixture of isopropyl- or tert-butyl-triphenyl phosphates (ITPs or TBPPs), were the most frequently detected FR (34%), followed by tris(1,3-dichloroisopropyl) phosphate (TDCIPP; 25%), TPHP with a mixture of polybrominated diphenyl ethers (BDE-47, 99, 100, 153 and 154; 20%) and tris(2-chloroethyl) phosphate (TCEP; 11%). Upholstered furniture components collected after enactment of the new legislation had a median FR concentration of 2600 mg/kg (range: 1160–49,800 mg/kg, outlier sample 282,200 mg/kg), with 11.9% of the foam samples and no textile samples containing ∑FR > 1000 mg/kg. Of these samples, tris(1-chloro-2-propyl) phosphate (TCIPP) was the most frequently detected FR (55%), followed by TDCIPP (30%) and Firemaster (FM 550, 15%). No PBDEs were detected in the post-regulatory intervention products. Our initial work on children's products showed 15% of the samples contained ∑FR > 1000 mg/kg. In our post- AB 2998 work, no regulated children's product components failed compliance (i.e., ∑FR > 1000 mg/kg).The data confirm successful adoption of the new regulations with most samples in compliance, demonstrating the efficacy of regulatory intervention. Given these results, environmental FR exposure is expected to decrease as older FR treated consumer products are replaced with FR free products.

Novel Brominated Flame Retardants in Dust from E-Waste-Dismantling Workplace in Central China: Contamination Status and Human Exposure Assessment.

Novel brominated flame retardants (NBFRs) have been widely used as alternatives to legacy BFRs. However, information on the contamination status and human exposure risks of electronic waste (e-waste)-derived NBFRs in the e-waste workplace is limited. In this study, six NBFRs and the legacy BFRs, hexabromocyclododecanes (HBCDs), were analyzed in 50 dust samples from an e-waste-dismantling workplace in Central China. The dust concentration of NBFRs in e-waste-dismantling workshops (median, 157-169 ng/g) was found to be significantly higher than those in an outdoor environment (17.3 ng/g) (p < 0.01). Differently, the highest median concentration of HBCDs was found in dust from the dismantling workshop for cellphones and computers (367 ng/g) among studied areas. The bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEHTBP) was the predominant compound, which contributed 66.0-88.0% of measured NBFR concentrations. NBFRs might originate from plastic and rubber materials in wastes based on the correlation and principal component analysis. Moreover, the total estimated daily intakes (average scenario) of NBFRs were calculated at 2.64 × 10-2 ng/kg bw/d and 2.91× 10-2 ng/kg bw/d for the male and female dismantling workers, respectively, via dust ingestion, inhalation, and dermal contact pathways, which were lower than the reference dose values, and thus indicated a limited human exposure risk for NBFRs at the current level. Although the dust concentrations and daily intakes of NBFRs were still lower than those of other emerging pollutants (e.g., organophosphate and nitrogenous flame retardants) measured in the same sampling set, the elevated levels of NBFRs suggested the progressive BFR replacement process in China, which deserves more attention regarding their adverse effects on both the environment and human health.

Elevated concentrations of halogenated flame retardants in waste childcare articles from Ireland

Concentrations of legacy and alternative halogenated flame retardants (HFRs) including chlorinated organophosphate esters (Cl-OPEs), were measured in waste childcare articles (n = 275 for Cl-OPEs, n = 187 for other HFRs) from the Republic of Ireland between 2019 and 2020. Articles studied comprised foams and fabrics from: child car seats, cot mattresses, changing mats, pushchairs, prams, and related items. Fifteen articles (7.7%) exceeded the European Union limit value of 1000 mg/kg for polybrominated diphenyl ethers (PBDEs) (all due to BDE-209), an additional 15 exceeded the limit for hexabromocyclododecane (HBCDD), with 7 articles exceeding the limit for both PBDEs and HBCDD. An even greater proportion of articles contained concentrations exceeding 1000 mg/kg for: tris(1-chloro-2-propyl) phosphate (TCIPP) (n = 73, 27%) and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (n = 58, 21%), with concentrations greater than 1000 mg/kg also observed for: tris(2-chloroethyl) phosphate (TCEP) (n = 14, 5.1% articles), 2-ethylhexyl tetrabromobenzoate (EH-TBB) (n = 7, 3.7%), decabromodiphenyl ethane (DBDPE), and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) (both n = 5, 2.7%). Overall, 120 samples contained at least one HFR at a concentration exceeding 1000 mg/kg. In addition to the waste management implications of our findings, our data raise concerns about child exposure to HFRs during the use phase of these everyday items.

In vitro neurotoxic potential of emerging flame retardants on neuroblastoma cells in an acute exposure scenario

Since 2004, some legacy flame retardants (FRs) were restricted or removed from the European markets due to their concern on human health. Both organophosphorus FRs (OPFRs) and novel brominated FRs (NBFRs) have replaced them because they are presumably safer and less persistent emerging FRs (EFRs) and their exposure is currently occurring in indoor environments at high levels. Little is known about the neurotoxic potential risk of these EFRs in humans. The present study was aimed at assessing the acute neurotoxicity potential of Tris(1, 3-dichloro-2-propyl)phosphate (TDCPP), triphenyl phosphate (TPhP), Bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) on human neuroblastoma cells (SH-SY5Y). SH-SY5Y were exposed to these EFRs at low concentrations -ranging 2.5–20 μM. during 2–24 h. We investigated viability, mitochondrial function, oxidative stress, inflammatory response, as well as neural plasticity and development. The results have demonstrated that selected EFRs (TDCPP, TPhP, EH-TBB and BEH-TBP) did not impair neural function on SH-SY5Y as acute response. To the best of our knowledge, this has been the first study focused on evaluating the neural affection of TPhP on SH-SY5Y cells and of EH-TBB and BEH-TBP on neural cells. We also assessed for the first time almost all endpoints after FR exposure on neural cell lines.

Emerging Brominated Flame Retardants 2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and Bis(2-ethylhexyl)-tetrabromophthalate (BEH-TEBP) in Chinese Food and Their Health Implications.

2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP) have been frequently detected in the environment, whereas studies in food are scare. The European Food Safety Authority has requested data for their risk assessment. Herein, dietary exposure and hazard quotient (HQ) were studied based on the 5th (2009-2012) and 6th (2015-2018) Chinese total diet studies (TDSs). EHTBB was found in 61.1 and 75.9% of the two TDS sample sets, respectively. The concentrations of EHTBB in animal-derived food were higher than those in plant-derived food. The estimated daily intakes (EDIs) were 1.33 and 0.97 ng/kg bw/day, and vegetables contributed to 48.5 and 39.2% of the EDIs based on the 5th and 6th TDS, respectively. The dietary exposure to EHTBB was similar to that to hexabromocyclododecane, brominated diphenyl ether-209, and tetrabromobisphenol A (TBBPA). The HQ for EHTBB was similar to that for decabromodiphenyl ethane and surpassed that for TBBPA. Therefore, EHTBB warrants further study in food.

Novel brominated flame retardants - A review of their occurrence in indoor air, dust, consumer goods and food

This critical review summarizes the occurrence of 63 novel brominated flame retardants (NBFRs) in indoor air, dust, consumer goods and food. It includes their EU registration and (potential) risks. The increasing application of NBFRs calls for more research on their occurrence, environmental fate and toxicity. This review reports which NBFRs are actually being studied, which are detected and which are of most concern. It also connects data from the European Chemical Association on NBFRs with other scientific information. Large knowledge gaps emerged for 28 (out of 63) NBFRs, which were not included in any monitoring programs or other studies. This also indicates the need for optimized analytical methods including all NBFRs. Further research on indoor environments, emission sources and potential leaching is also necessary. High concentrations of 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were often reported. The detection of hexabromobenzene (HBB), pentabromotoluene (PBT), 1,4-dimethyltetrabromobenzene (TBX), 4-(1,2-dibromoethyl)-1,2-dibromocyclohexane (DBE-DBCH) and tetrabromobisphenol A bis(2,3-dibromopropyl) ether (TBBPA-BDBPE) also raises concern.

Organophosphate and novel brominated flame retardants exposure in childbearing women via house dust

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background: Polybrominated diphenyl ethers, suspected endocrine disruptors, have been replaced by organophosphate (OPFR) and novel brominated flame retardants (NBFR). OPFRs and NBFRs readily migrate from consumer products, including furniture and electronics, into dust where humans are exposed via accidental ingestion and inhalation. Toxicological studies have found potential carcinogenicity, endocrine disruption, and neurobehavioral alterations from these alternative flame retardants. However, no comprehensive assessments of exposure to OPFRs and NBFRs have been completed in a longitudinal cohort. Methods: We quantified concentrations of OPFRs and NBFRs in house dust samples (n=317) collected from pregnant women (~20 weeks) enrolled in the Health Outcomes and Measures of the Environment (HOME) Study in Cincinnati, Ohio (2003-2006). We used multiple regression modeling to identify personal characteristics that were associated with concentrations of individual chemicals and summary concentrations for each class. Finally, we estimated personal daily dust exposure for each participant based on dust concentration and cross-sectional weight data. Results: Tris(1-chloro-2-propyl)phosphate (TCIPP) (median: 1860 ng/g, range: 70.1-166,000 ng/g), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) (median: 1860 ng/g, range: 55.2-228,000 ng/g), triphenyl phosphate (TPHP) (median: 995 ng/g, range: 34.1-62,100 ng/g), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) (median: 45.8 ng/g, range: 2.82-7,800 ng/g), and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) (median: 115 ng/g, range 2.17-13,600 ng/g) were all detected in over 90% of dust samples; tris(2-chloroethyl)phosphate (TCEP) (median: 759.4 ng/g, range: 56.8-160,000 ng/g) was detected in 80.1% of samples. Concentrations of individual chemicals, ∑OPFRs, and ∑NBFRs were associated with the number of people living in the home, race, education, floor type, and visible cleanliness of the room. Daily exposure to ∑OPFRs from dust was 2.1 ng/kg/day based on average dust ingestion and 6.3 ng/kg/day among women in the 95th percentile of dust ingestion. Conclusions: This study shows that OPFRs and NBFRs are ubiquitous in childbearing women’s house dust, and justifies more research on the consequences of exposure in these concentration ranges.

Brominated and organophosphorus flame retardants in South African indoor dust and cat hair

Flame retardants (FRs), such as brominated flame retardants (BFRs) and organophosphorus flame retardants (OPFRs), are diverse groups of compounds used in various products related to the indoor environment. In this study concentrations of eight polybrominated diphenyl ethers (PBDEs), two alternative BFRs and ten OPFRs were determined in indoor dust (n = 20) and pet cat hair (n = 11) from South Africa. The OPFRs were the major FRs, contributing to more than 97% of the total FR concentration. The median Ʃ10OPFRs concentrations were 44,800 ng/g in freshly collected dust (F-dust), 19,800 ng/g in the dust collected from vacuum cleaner bags (V-dust), and 865 ng/g in cat hair (C-hair). Tris(1-chloro-2-propyl) phosphate (TCIPP) was the dominant OPFR in the dust samples with median concentrations of 7,010 ng/g in F-dust and 3,590 ng/g in V-dust. Tris(2-butoxyethyl) phosphate (TBOEP) was the dominant OPFR in C-hair, with a median concentration of 387 ng/g. The concentrations of Ʃ8PBDEs were higher in F-dust than in V-dust. BDE209 was the dominant BFR in all three matrices. Bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5- tetrabromobenzoate (EH-TBB) showed notable contributions to the BFR profile in cat hair. A worst-case dust exposure estimation was performed for all analytes. The estimated TCIPP daily intake through dust ingestion was up to 1,240 ng/kg bw for toddlers. The results indicate that OPFRs are ubiquitous in South African indoor environment. Indoor dust is a major source of human exposure to environmental contaminants. This can for example occur through hand-to-mouth contact of toddlers, and is an important route of exposure to currently used FRs accumulated on dust particles. The presence of FRs, in particular high concentrations of OPFRs, suggests that children and indoor pet cats may have greater exposure to FRs than adults.

Novel brominated flame retardants in house dust from Shanghai, China: levels, temporal variation, and human exposure

BackgroundNovel brominated flame retardants (NBFRs) have been increasingly used as alternatives to legacy BFRs (e.g., PBDEs and HBCDs) in consumer products, but are liable to emigrate and contaminate indoor dust. In this study, a total of 154 house dust samples including floor dust (FD) and elevated surface dust (ESD) were collected in the biggest metropolitan area (Shanghai) of East China in 2016. Limited information about temporal variation of NBFRs indoors is available, while the period of sampling is influential in human exposure estimates. Levels, temporal variation, and human exposure of seven target NBFRs such as decabromodiphenylethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EHTBB), and bis(2-ethylhexyl) tetrabromophthalate (BEHTEBP) were investigated in indoor house dust.ResultsConcentrations of ∑7NBFRs ranged from 19.11 to 3099 ng/g with a geomean of 295.1 ng/g in FD, and from 34.74 to 404.6 ng/g with a geomean of 117.9 ng/g in ESD. The geomeans of DBDPE were 219.6 ng/g in FD and 76.89 ng/g in ESD, accounting for 90.5% and 80.5% of ∑7NBFRs. Levels of EHTBB, BTBPE, and DBDPE in FD exceeded significantly those in ESD. The temporal variation in ∑7NBFRs in FD was ranked as summer > winter > autumn > spring. The daily exposure doses (DEDs) of ∑7NBFRs via dust ingestion decreased as: infants > toddlers > children > teenagers > adults. Infants showed the highest DED in FD, 9.1 ng/kg bw/day.ConclusionsDBDPE clearly dominated the NBFRs in both FD and ESD, but the concentrations of DBDPE in this study were generally moderate compared with the other international studies. Dust ingestion was the major pathway of human exposure to NBFRs indoors. About eightfold difference in exposure estimates between infants and adults showed that infants faced elevated exposure risks in FD. This study highlighted the necessity to estimate human exposure of NBFRs for different age groups using FD and ESD, respectively.

Current-use halogenated and organophosphorous flame retardants: A review of their presence in Arctic ecosystems

Abstract Since the ban of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), other flame retardants may be increasingly used. Thirty-one current-use halogenated (HFRs) and 24 organophosphorous flame retardants (PFRs) have been sought in Arctic ecosystems so far. Air measurements provide evidence of long-range atmospheric transport for the majority of these compounds, with much higher concentrations for PFRs than for HFRs. Some HFRs, i.e. bis(2-ethylhexyl)-tetrabromophthalate (BEH-TEBP), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and hexabromobenzene (HBBz), had air concentrations comparable to those of PBDEs in some studies. Complementary data for seawater and ice indicate dry deposition of HFRs, while net volatilization from seawater was observed for some PFRs. Studies in the marine environment indicate a wide presence of HFRs in marine biota, but generally at low levels, i.e. typically lower than those of PBDEs. Exceptions exist, namely 2,4,6-tribromophenyl 2,3-dibromopropyl ether (TBP-DBPE) and decabromodiphenyl ethane (DBDPE), which were found in concentrations comparable to PBDEs in some species. The same was the case for 2,4,6-tribromophenyl allyl ether (TBP-AE) in a study from the terrestrial environment. PFRs generally had low concentrations in biota, probably due to metabolic transformation of PFR triesters, as suggested by in vitro studies. Elevated PFR concentrations occurred in some individuals, generally indicating a larger variability of PFRs in biota than found for HFRs. The commercially important tetrabromobisphenol A (TBBPA) was only detected sporadically, and only in abiotic matrices.

Polybrominated diphenyl ethers and novel brominated flame retardants in indoor dust of different microenvironments in Beijing, China

The occurrence levels of eight polybrominated diphenyl ethers (PBDEs) and four novel brominated flame retardants (NBFRs) were determined and compared in indoor dust from different microenvironments (21 homes, 23 offices and 16 day care centers) in Beijing, China. Concentrations of ∑8PBDEs in dust were 430–17,000 ng/g, 690–8600 ng/g, and 90–2300 ng/g for homes, offices, and day care centers, respectively, and were dominated by BDE-209. Concentrations of ∑4NBFRs ranged from 310 to 17,000 ng/g, 300 to 4300 ng/g, and not detected to 500 ng/g for homes, offices, and day care centers, respectively, and were dominated by bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TEBP) and decabromodiphenylethane (DBDPE) across microenvironments. The results showed an increasing detection and elevated concentration of NBFRs (especially BEH-TEBP), indicating that monitoring of NBFRs in dust samples should be of concern in future studies. A notable finding was that the BFR concentrations in dust samples from day care centers were generally one order of magnitude lower than those from homes and offices in the present study. This implies that previous estimates of toddler exposure via dust ingestion on data from homes may be overestimated. Concentrations of BDE-209 and ∑8PBDEs were found to be significantly higher in elevated surface dust than floor dust from day care centers. The estimates of daily intakes of BFRs via dust ingestion for Chinese adults and toddlers using Monte Carlo analysis were 2–5 orders of magnitude lower than the corresponding reference daily intakes.

Exposure to Brominated and Organophosphate Ester Flame Retardants in U.S. Childcare Environments: Effect of Removal of Flame-Retarded Nap Mats on Indoor Levels

Nap mats are a significant item in childcare settings used for children naptime. Typically, they are one- to two-inch thick mattresses made of polyurethane foam encased in a vinyl cover. Childcares that serve young children in full-day programs generally use, and store, one nap mat for each child. For this study, we conducted an intervention, replacing flame-retarded nap mats with flame-retardant-free mats, and measured concentrations of flame retardants in indoor air and dust before and after replacement. Seven childcare centers in Seattle, USA, were recruited to participate in the study using the following criteria: regular use of nap mats, serving low-income families, and minimal presence of other foam-containing items. Foam from existing in-use nap mats from each center was analyzed to confirm the presence of flame retardants. Foam and fabric from replacement mats was also analyzed for flame retardants to identify flame-retardant-free products. Existing mats were replaced with flame-retardant-free mats or cots in six centers. The predominant FRs found in dust and indoor air were 2-ethylhexyl tetrabromobenzoate (EHTBB) and tris(1-chloro-2-propyl) phosphate (TCIPP), respectively. Naps mat samples analyzed from five of the seven centers contained a Firemaster® mixture, while one mat was predominantly treated with tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and the other contained no detectable target FRs. After replacement, there was a significant decrease (p = 0.03-0.09) in median dust concentrations for bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), EHTBB, tris(4-butylphenyl) phosphate (TBPP), and TDCIPP with reductions of 90%, 79%, 65%, and 42%, respectively. These findings suggest that the nap mats were an important source of these FRs to dust in the investigated childcare environments and that a campaign of swapping out flame retarded mats for FR-free ones would reduce exposure to these chemicals.

Flame Retardant Metabolites in Addled Bald Eagle Eggs from the Great Lakes Region

Organophosphate esters (OPEs) and other alternative flame retardants including 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl) tetrabromophthalate (BEHTBP) are ubiquitous in the Great Lakes region, having been detected in air, water, and biota samples. In a recent study, however, we showed that concentrations of six OPEs in eagle eggs were generally low (geometric mean 24 ng/g ww), and the two main Firemaster (FM) components, EHTBB and BEHTBP, were below limits of detection. We therefore hypothesized that the low levels of these compounds in bald eagles may be due to a potential rapid metabolic transformation. We measured metabolites of triaryl and trialkyl phosphates and brominated Firemaster (FM) flame retardants in 21 addled bald eagle (Haliaeetus leucocephalus) eggs from 2000 to 2012 from the Michigan Bald Eagle Biosentinel Program archive. Sampling sites were divided into two groups: inland (IN) and Great Lakes (GL) based on breeding areas. Results suggest that the most abundant...

Exposure to brominated and organophosphate ester flame retardants in U.S. childcare environments: Effect of removal of flame-retarded nap mats on indoor levels

We assessed exposure to 39 brominated and 16 organophosphate ester flame retardants (FRs) from both dust and indoor air at seven childcare centres in Seattle, USA, and investigated the importance of nap mats as a source of these chemicals. Many childcare centres serving young children use polyurethane foam mats for the children's naptime. Until recently, the vast majority of these mats sold in the United States contained flame-retarded polyurethane foam to meet California Technical Bulletin 117 (TB117) requirements. With the 2013 update of TB117, allowing manufacturers to meet flammability standards without adding FRs to filling materials, FR-free nap mats have become widely available. We conducted an intervention study by actively switching out FR-treated nap mats with FR-free nap mats and measuring FR levels in indoor air and dust before and after the switch-out. The predominant FRs found in dust and indoor air were 2-ethylhexyl tetrabromobenzoate (EHTBB) and tris(1-chloro-2-propyl) phosphate (TCIPP), respectively. Nap mat samples analysed from four of the six centres contained a Firemaster® mixture, while one mat was predominantly treated with tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and the other contained no detectable target FRs. After replacement, there was a significant decrease (p = 0.03–0.09) in median dust concentrations for bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), EHTBB, tris(4-butylphenyl) phosphate (TBPP), and TDCIPP with reductions of 90%, 79%, 65%, and 42%, respectively. These findings suggest that the nap mats were an important source of these FRs to dust in the investigated childcare environments and that a campaign of swapping out flame-retarded mats for FR-free ones would reduce exposure to these chemicals. While calculated exposure estimates to the investigated FRs via inhalation, dust ingestion, and dermal absorption were below established reference dose values, they are likely underestimated when considering the toddlers' direct contact to the mats and personal cloud effects.

Assessment of dermal exposure to halogenated flame retardants: Comparison using direct measurements from hand wipes with an indirect estimation from settled dust concentrations

There are few studies estimating dermal exposure to halogenated flame retardants in adults. To fill this gap, sixty-one hand wipe samples were collected from a Norwegian adult cohort using gauze pads immersed in isopropanol. BDE-47, BDE-209, bis(2‑ethyl‑hexyl)‑3,4,5,6‑tetrabromophthalate (BEH-TEBP) and decabromodiphenylethane (DBDPE) were the most frequently detected chemicals. The highest median mass in hand wipes was that of sumEHFR (570 ng), followed by sumHBCDD (180 ng) and sumPBDE (2.9 ng). The high EHFR level was mainly driven by tetrabromobisphenol A (TBBPA) which accounted for 77% of the total mass. Positive and significant correlations were observed between FR levels in hand wipes and settled dust (0.26 < r < 0.56, p < 0.05), as well as between FR levels in hand wipes and the number of electronic consumer products at home (0.27 < r < 0.40, p < 0.05). Significant bivariate associations with number of laptops/tablets and phones/mobiles were further confirmed by multivariate linear regression analyses. Dermal exposure was estimated using the levels measured in handwipes. The estimated median dermal exposure was 2600, 840 and 6.2 pg/kg bw/d for sumEHFR, sumHBCDD and sumPBDE, respectively. Further, we compared these results with the dermal exposure as estimated indirectly by utilizing previously reported FR levels in settled dust collected from the residences of the same studied cohort. With the indirect approach, higher dermal exposures to sumPBDE but lower exposures to sumEHFR and sumHBCDD were observed compared to the direct dermal exposure estimated via hand wipes. Comparable exposure estimates between hand wipes and the indirect method were obtained for α‑, β‑tetrabromoethylcyclohexane (DBE-DBCH), DBDPE, BDE-28, -35, -49, -99, -153, 154, and -183. For other individual HFRs, the exposure estimates obtained from the two approaches were significantly different (Mann-Whitney U test, p < 0.05). Both methods gave similar dermal exposure estimates for many individual FRs. However, it is important to be aware of the value and limitations of each method when using them to estimate human exposure.

Atmospheric concentrations of hexabromocyclododecane (HBCDD) diastereomers in the Great Lakes region

The concentrations of α-, β-, and γ-hexabromocyclododecane (HBCDD) diastereomers in atmospheric particle phase samples were determined at four United States Integrated Atmospheric Deposition Network (IADN) sites located in the North American Great Lakes basin collected between 1 January and 31 December 2014. The concentrations ranged from 0.37 to 8.9 pg/m3, 0.12–4.0 pg/m3, and 0.26–22 pg/m3 for α-, β-, and γ-HBCDD, respectively among the four sampling sites. The median ΣHBCDD concentrations for the four sites were 2.0 pg/m3, 2.1 pg/m3, 1.7 pg/m3 and 5.2 pg/m3 for Chicago, Cleveland, Sturgeon Point and Sleeping Bear Dunes, respectively. Higher levels of ∑HBCDD were observed at the remote site of Sleeping Bear Dunes with comparable levels at the remaining three sites. α-HBCDD and γ-HBCDD were the dominant isomers with an average contribution of about 40% and 50% to ΣHBCDD concentrations, respectively. These HBCDD concentrations were compared with the levels of other brominated flame retardants measured in these samples, including polybrominated diphenyl ethers (PBDEs), 2,3,4,5-tetrabromoethylhexyl benzoate (EHTBB), bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), and decabromodiphenylethane (DBDPE). ∑HBCDD concentrations were significantly lower than or indistinguishable from those of PBDEs, EHTBB, BEHTBP, and DBDPE at all sites except Sleeping Bear Dunes. No significant correlations were found between ΣHBCDD and ΣPBDE, EHTBB, BEHTBP, and DBDPE concentrations, suggesting a different source of HBCDD contamination. This is the first study reporting concentrations of HBCDD isomers in the Great Lakes ambient air, and our results indicate that HBCDD is ubiquitous in the Great Lakes basin, including at remote sites.

Levels of Non-PBDE Halogenated Fire Retardants and Brominated Dioxins and their Toxicological Effects in Indoor Environments - A Review

Non-polybrominated diphenyl ether (non-PBDE) halogenated fire retardants (HFRs) such as new or novel brominated fire retardants (NBFRs) and dechlorane plus (DP) have been widely spread in the environment and recognized as emerging persistent organic pollutants (POPs) in the recent years, mainly due to the continuous increase in their global demand, especially after the worldwide restrictions on PBDE use. Polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) are the unintentional byproducts of PBDE commercial formulations in the indoor environment. Although HFRs, including NBFRs, DP, and PBDD/Fs, are ubiquitous in the indoor environment due to the large-volume release from the surfaces of consumer products, only a few in vitro and in vivo studies have addressed their toxic effects. In this review article, global data on NBFRs, including decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TEBP), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), DP, including syn-DP and anti-DP, and PBDD/Fs in indoor aerosol and dust are summarized from recent literature. Based on the gathered data, indoor dust is a major sink for indoor contamination and is of great concern due to the fact that dust ingestion is one of the primary routes for human exposure to these chemicals. Lastly, the toxic effects of NBFRs, DP, and PBDD/Fs identified in in vitro and in vivo studies are summarized and discussed based on the current published reports. However, there is still a lack of sufficient toxicity data for assessing their risks. Future works are encouraged to focus on indoor PM2.5-bound HFR levels to further evaluate their toxic effects on human health.

Determination of legacy and novel brominated flame retardants in dust from end of life office equipment and furniture from Pretoria, South Africa

Indoor dust is known to be a source of human exposure to brominated flame retardants (BFRs) and these consists of the legacy polybrominated diphenyl ethers (PBDEs), total hexabromocyclododecane (T-HBCDD) and the “Novel or alternate” Brominated flame retardants (NBFRs). In this study, x-ray fluorescence (XRF) analyser was employed to measure elemental bromine contents in office furniture and electronics as the first indication of the possible presence of BFRs. To investigate the possible BFRs present, a total of 21 dust samples were collected from surfaces of electronic equipment and office furniture and were analysed using gas chromatography–mass spectrometry (GC–MS). The concentrations of ∑7 BDE- congeners ranged from 50 to 3346ngng−1. Of the ∑7 BDE congeners analysed, BDE-209, −183 and −99 were the most dominant congeners. The concentrations observed ranged from <LOD - 1758, <LOD - 401 and <LOD-543ngg−1, for BDE-209, −183 and −99, respectively. T-HBCDD and 2-ethyl-1-hexyl-2.3.4.5-tetrabromobenzoate (EH-TBB) were detected in 57 and 67% of the total dust samples analysed with concentrations ranging from <LOD - 673 and <LOD – 385ngg−1, respectively. However, Bis (2-ethylhexyl) tetrabromophthalate (BEH-TEBP) was only detected in 24% of the 21 samples exhibiting a concentration range of <LOD - 63ngg−1. The detection frequency of 1,2 Bis (2.4.6-tribromophenoxy) ethane (BTBPE) was 81% with concentrations of <LOD-1402ngg−1. Alongside the legacy BFRs, NBFRs were the most detected indicating probably increased usage as replacements for the banned commercial PBDEs products namely, penta-, octa-, and deca-BDE mixtures. No correlation was observed between the bromine levels obtained using portable XRF and the BFRs detected using GC–MS (r=0.0073, p=0.076). The observed trend may be attributed to various factors including the sample matrix analysed and the number of BFRs analysed. The observed trend is consistent with those reported from other studies.

Waste-water treatment plants are implicated as an important source of flame retardants in insectivorous tree swallows (Tachicyneta bicolor)

Wastewater treatment plants (WWTPs) are an important source of anthropogenic chemicals, including organic flame retardants (FRs). Limited studies indicate birds can be exposed to FRs by feeding from waters receiving WWTP effluent or in fields receiving biosolids. Expanding on our earlier study, 47 legacy and 18 new FR contaminants were characterized in the eggs of insectivorous tree swallows (Tachycineta bicolor) feeding in water bodies receiving effluent from two WWTPs and compared to those from a reference site 19 km downstream of the nearest WWTP. Of the FRs measured, polybrominated diphenyl ethers (PBDEs) dominated the FR profile, specifically BDE-47, -99, -100, -153, -154, with considerably lower concentrations of hexabromocyclododecane (HBCDD), BDE-183 and BDE-209; each detected in 96–100% of the eggs overall except HBCDD (83%). FR concentrations were usually significantly greater in eggs from the secondary WWTP versus the tertiary WWTP and/or reference site. Despite low detection rates, concentrations of new FRs, specifically pentabromobenzyl acrylate (PBBA), 1,2,-bis-(2,4,6-tribromophenoxy)ethane (BTBPE), bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP), tetrabromo-o-chlorotoluene (TBCT), hexabromobenzene (HBB), α- and β-1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH), were greater than HBCDD or BDE-209. Additional evidence that WWTPs are an important source of exposure to new FR contaminants for birds utilizing associated water bodies is that only the WTTP eggs, not the reference eggs, had measureable concentrations of PBBA, TBCT, BEHTBP, HBB, α-DBE-DBCH, 2,2′,4,5,5′-pentabromobiphenyl (BB-101), pentabromoethyl benzene (PBEB), 2,4,6-tribromophenyl allyl ether (TBPAE), and tetrabromo-p-xylene (pTBX). Our study suggests that WWTPs are an important source of legacy and new FR contaminants for birds consuming prey that are associated with WWTP out-flows.