Abstract  BACKGROUND: Flame retardant chemicals are used in materials on airplanes to slow the propagation of fire. These chemicals migrate from their source products and can be found in the dust of airplanes, creating the potential for exposure.

METHODS: To characterize exposure to flame retardant chemicals in airplane dust, we collected dust samples from locations inside 19 commercial airplanes parked overnight at airport gates. In addition, hand-wipe samples were also collected from 9 flight attendants and 1 passenger who had just taken a cross-country (USA) flight. The samples were analyzed for a suite of flame retardant chemicals. To identify the possible sources for the brominated flame retardants, we used a portable XRF analyzer to quantify bromine concentrations in materials inside the airplanes.

RESULTS: A wide range of flame retardant compounds were detected in 100% of the dust samples collected from airplanes, including BDEs 47, 99, 153, 183 and 209, tris(1,3-dichloro-isopropyl)phosphate (TDCPP), hexabromocyclododecane (HBCD) and bis-(2-ethylhexyl)-tetrabromo-phthalate (TBPH). Airplane dust contained elevated concentrations of BDE 209 (GM: 500 ug/g; range: 2,600 ug/g) relative to other indoor environments, such as residential and commercial buildings, and the hands of participants after a cross-country flight contained elevated BDE 209 concentrations relative to the general population. TDCPP, a known carcinogen that was removed from use in children's pajamas in the 1970's although still used today in other consumer products, was detected on 100% of airplanes in concentrations similar to those found in residential and commercial locations.

CONCLUSION: This study adds to the limited body of knowledge regarding exposure to flame retardants on commercial aircraft, an environment long hypothesized to be at risk for maximum exposures due to strict flame retardant standards for aircraft materials. Our findings indicate that flame retardants are widely used in many airplane components and all airplane types, as expected. Most flame retardants, including TDCPP, were detected in 100% of dust samples collected from the airplanes. The concentrations of BDE 209 were elevated by orders of magnitude relative to residential and office environments.

Abstract  Alternative brominated flame-retardants (BFRs), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), 2-ethylhexyl 2,3,4,5-tetrabromophthalate (TBPH), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE), are now being detected in the environment. However, contaminant bioavailability is influenced by the organisms' ecology (i.e., route of uptake) and in situ environmental factors. We observed that the filter-feeding bivalve (Corbicula fluminea) and grazing gastropod (Elimia proxima), collected downstream from a textile manufacturing outfall, exhibited TBB, TBPH, and BTBPE concentrations from 152 to 2230 ng g(-1) lipid weight (lw). These species also contained additional BFRs. Maximum levels of total hexabromocyclododecane diastereomers (∑HBCDs) in these species were 363,000 and 151,000 ng g(-1) lw, and those of polybrominated diphenyl ethers (∑PBDEs) were 64,900 and 47,200 ng g(-1) lw, respectively. These concentrations are among the highest reported to date worldwide. While BDE-209 was once thought to be nonbioavailable and resistant to degradation, it was the dominant BFR present and likely debromination products were detected. Contributions of α- and β-HBCD were higher in tissues than sediments, consistent with γ-HBCD bioisomerization. Mollusk bioaccumulation factors were similar between HBCD and PBDEs with 4 to 6 bromines, but factors for TBB, TBPH, and BTBPE were lower. Despite different feeding strategies, the bivalves and gastropods exhibited similar BFR water and sediment accumulation factors.

Abstract  Hexabromocyclododecanes (HBCDs) are raising concern because of their potential persistence, bioaccumulation, and toxicity. In this study, we investigated the concentrations, diastereoisomer- and enantiomer-specific profiles, and mass inventories of HBCDs in 90 surface soils from two e-waste recycling areas (Qingyuan, Guiyu) and from industrial areas in South China. The mean concentrations of total HBCDs in the surface soils ranged from 0.22 to 0.79 and from 0.31 to 9.99 ng/g dw for two surrounding e-waste recycling sites and industrial areas, respectively. The highest total HBCD concentration (284 ng/g dw) was found at the e-waste recycling site in Qingyuan, while total HBCD levels fell dramatically with increasing distance from the recycling site, suggesting that the e-waste recycling activities were an important source of HBCDs. The diastereoisomer profiles in 75 of the 90 soil samples differed from those of the commercial products. The mean enantiomeric fraction values for α-, β-, and γ-HBCDs in soils ranged from 0.503(0.010) to 0.507(0.003), 0.494(0.003) to 0.506(0.009), and 0.502(0.003) to 0.511(0.006), respectively, suggesting that there was no stereoselective transformation of the three diastereoisomers. The mass inventories of HBCDs gave preliminarily estimates of 3.42 kg and 1.84 tonnes for the e-waste recycling areas and industrial areas, respectively. It is notable that the diasteroisomer and enantiomer profiles of this study failed to distinguish definitely that the isomeric transformation occurred during the product processing or in the environmental matrix. Further laboratory studies on abiotic and biotic transformation are needed to clarify this issue.

Abstract  Use of brominated flame retardants (BFRs) in soft furnishings has occurred for over thirty years with the phase out of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) only relatively recently begun. As products treated with BFRs reach the end of their lifecycle they enter the waste stream, thereby constituting an important and increasing reservoir of these chemicals. This review highlights the dearth of data on the extent and potential mechanisms of BFR emissions from waste soft furnishings. However, insights into what may occur are provided by scrutiny of the larger (though still incomplete) database related to BFR emissions from electronic waste (e-waste). In many countries, municipal landfills have historically been the primary disposal method of waste consumer products and therefore represent a substantial reservoir of BFRs. Published data for BFR emissions to both air and water from landfill and other waste disposal routes are collated, presented and reviewed. Reported concentrations of PBDEs in landfill leachate range considerably from <1ngL(-1) to 133,000ngΣPBDEL(-1). In addition to direct migration of BFRs from waste materials; there is evidence that some higher brominated flame retardants are able to undergo degradation and debromination during waste treatment, that in some instances may lead to the formation of more toxic and bioavailable compounds. We propose that waste soft furnishings be treated with the same concern as e-waste, given its potential as a reservoir and source of environmental contamination with BFRs.

Abstract  Written by prominent scholars from industry, academia, and research institutions, the Kirk-Othmer Encyclopedia of Chemical Technology presents a wide scope of articles on chemical substances—including their properties, manufacturing, and uses. It also focuses on industrial processes and unit operations in chemical engineering, as well as covering fundamentals and scientific subjects related to the field. Additionally, environmental and health issues concerning chemical technology are also addressed. Key features of the Kirk-Othmer Encyclopedia of Chemical Technology Online include: - Over 1,300 articles -- with content updated regularly - New and updated articles keep the online version on the cutting edge of chemical technology - Previous versions of articles are archived for posterity - An easy to use interface that allows one to Search or Browse through the articles for quick reference and convenience

Abstract  Polystyrene (PS) is made flame retardant by combining with hexabromocyclododecane (HBCD). HBCD can release from consumer products during their production, use or disposal. As a result, it has become a ubiquitous contaminant in the environment with a high potential for bioaccumulation. Therefore, to evaluate the extent of exposure to HBCD from PS, we determined the concentration of HBCD in a variety of products (n=34) made from three types of commonly used PS: expanded PS (EPS), extruded PS foam (XPS), and extruded PS. The concentration of HBCD was highest in EPS, with a mean value and range of 475643±16710ngg(-1) and 106-960000ngg(-1), respectively. PS related to building construction and laboratory uses had a significantly higher concentration of HBCD (3300-905000ngg(-1)), except XPS styroboard (191±100ngg(-1)). Lower concentrations were measured in most food-related products (24.3-199ngg(-1)). However, a relatively high concentration of HBCD was detected in an ice box (960000±29000ngg(-1)), aquaculture buoy (53500±2100ngg(-1)), and disposable tray (8430±730ngg(-1)) used in fish market, raising concern for public health. Our data demonstrate a wide variation in the concentration of HBCD, suggesting a lack of proper controls for the addition of HBCD to PS products. Other brominated flame retardants (BFRs) were also detected in a majority of the XPS products (TBBPA=3.83-545ngg(-1), BTBPE=44-216ngg(-1) and DBDPE=215-4200ngg(-1)). Thus, HBCD is being added to PS along with other BFRs that cannot be ignored.

Abstract  Hexabromocyclododecanes (HBCDs) have been used for flame retardation mainly in expanded polystyrene (EPS) and extruded polystyrene (XPS) insulation foams. Controlled incineration experiments with solid wastes containing each of EPS and XPS were conducted using a pilot-scale incinerator to investigate the destruction behavior of HBCDs and their influence on the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs). EPS and XPS materials were respectively blended with refuse derived fuel (RDF) as input wastes for incineration. Concentrations of HBCDs contained in the EPS- and XPS-added RDFs, were 140 and 1100mgkg(-1), respectively. In which γ-HBCD was dominant (68% of the total HBCD content) in EPS-added RDF and α-HBCD accounted for 73% of the total HBCDs in XPS-added RDF. During the incineration experiments with EPS and XPS, primary and secondary combustion zones were maintained at temperatures of 840°C and 900°C. The residence times of waste in the primary combustion zone and flue gas in the secondary combustion zone was 30min and three seconds, respectively. HBCDs were steadily degraded in the combustion chambers and α-, β-, and γ-HBCD behaved similarly. Concentration levels of the total HBCDs in the bag filter exit gas for the two experiments with EPS and XPS were 0.7 and 0.6ngmN(-3), respectively. HBCDs were also not detected (<0.2ngg(-1)) in the bottom and fly ash samples. From the obtained results, it was calculated that HBCDs were sufficiently destroyed in the whole incineration process with destruction efficiencies of more than 99.9999 for both of EPS and XPS cases. For PBDD/DFs, the levels detected in the bottom and fly ash samples were very low (0.028ngg(-1) at maximum). In the case of XPS-added experiment, 2,3,7,8-TeBDD and 2,3,7,8-TeBDF were determined in the flue gas at levels (0.05-0.07ngmN(-3)) slightly over the detection limits in the environmental emission gas samples, suggesting HBCDs in XPS are possibly a precursor of detected PBDD/DFs. Operational care should be taken when the ratio of HBCD-containing polystyrene is increased in the input wastes just to make sure of formation prevention and emission control of PBDD/DFs. The concentrations and congener patterns of PCDD/DFs and dl-PCBs in the samples during the three experiments were not affected by an addition of HBCDs.

Abstract  Waste electrical and electronic equipment (WEEE) contains various hazardous substances such as flame retardants (FRs). Inhalation exposures to many FRs simultaneously among WEEE recycling site workers have been little studied previously. The breathing zone airborne concentrations of five brominated FR compounds tetrabromobisphenol-A (TBBP-A), decabromodiphenylethane (DBDPE), hexabromocyclododecane, 1,2-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, and one chlorinated FR (Dechlorane Plus®) were measured at four electronics recycling sites in two consecutive years. In addition, concentrations of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls were measured. The three most abundant FRs in personal air samples were PBDEs (comprising mostly of deca-BDE), TBBP-A, and DBDPE, with mean concentrations ranging from 21 to 2320 ng m(-)(3), from 8.7 to 430 ng m(-3), and from 3.5 to 360 ng m(-3), respectively. At two of the sites, the emission control actions (such as improvements in ventilation and its maintenance and changes in cleaning habits) proved successful, the mean levels of FRs in personal samples being 10-68 and 14-79% of those from the previous year or alternatively below the limit of quantification. At the two remaining sites, the reductions in FR exposures were less consistent. The concentrations reported may pose a health hazard to the workers, although evaluation of the association between FR exposure and adverse health effects is hampered by lacking occupational exposure limits. Therefore, the exposures should be minimized by adequate control measures and maintaining good occupational hygiene practice.

Abstract  An industrial hygiene survey was conducted at the El Dorado plant to determine employee exposure to phenol, tribromophenol (TBP), ethylene dibromide (EDB) and epichlorohydrin in the fire-Master 680 (FM-680) unit and employee exposures to bromoacetaldehyde dimethyl acetal (BADMA), dibromoethyl acetate (DBEA), hexabromocyclododecane (HBCD), ethylene dichloride (EDC), methyl bromide and ethanol in the Semi-Works operations. The survey was performed by Neal Netzel, Industrial Hygienist, Environmental Health and Hygiene Department, during the week of March 6, 1978. The analytical support was furnished by both the Velsicol Ann Arbor Research facility and Clayton Environmental Consultants, Inc. Final lab results were received on April 17, 1978.