Environ. Sci. Technol. 2004, 38, 3247-3253
Identification of the Flame Retardant Decabromodiphenyl Ethane in the Environment A M E L I E K I E R K E G A A R D , * ,† JONAS BJO ¨ RKLUND,‡ AND U L R I K A F R I D EÄ N † Institute of Applied Environmental Research (ITM) and Department of Analytical Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
The brominated flame retardant decabromodiphenyl ethane, DeBDethane, is marketed as an alternative to decabromodiphenyl ether, BDE209. There are currently no data available about the presence of DeBDethane in the environment. In this study, DeBDethane was positively identified by high-resolution mass spectrometry and quantified by low-resolution mass spectrometry with electron capture negative ionization in sewage sludge, sediment, and indoor air. It was found in 25 of the 50 Swedish sewage treatment plants investigated, with estimated levels up to about 100 ng/g dry weight. The concentration of DeBDethane in sediment from Western Scheldt in The Netherlands was 24 ng/g dry weight, and in an air sample from a Swedish electronics dismantling facility it was 0.6 ng/ m3. DeBDethane was also found together with nonabromodiphenyl ethanes in water piping insulation. All samples contained BDE209 in higher concentrations as compared to DeBDethane (DeBDethane/BDE209 ratios ranging from 0.02 to 0.7), probably reflecting the higher and longer usage of BDE209. There is an ongoing risk assessment within the European Union regarding BDE209. Since DeBDethane has similar applications, it is important to investigate its environmental behavior before using it to replace BDE209.
Introduction Among the brominated flame retardants (BFR) in use, the polybrominated diphenyl ethers, PBDEs, have received attention because of their ubiquitous appearance in biota from both remote areas as well as near user sites (1). While DecaBDE is the major PBDE product in use, the most abundant congeners reported in biota are the lower brominated PBDEs (up to hexaBDE). High concentrations of BDE209 have previously been reported in, for example, sediment and sewage sludge (2-4). Because of its high molecular weight (mw 959.22 g/mol), BDE209 was assumed not to be bioavailable. However, lately BDE209 has been detected in human blood (5) and more recently in peregrine falcons (6). Partly as a result of these findings, a risk assessment of the BDE209 product is currently in progress within the European Union. Decabromodiphenyl ethane (DeBDethane) was introduced in the early 1990s under the trade name SAYTEX 8010 * Corresponding author phone: +46 8 674 71 82; e-mail:
[email protected]. † Institute of Applied Environmental Research. ‡ Department of Analytical Chemistry. 10.1021/es049867d CCC: $27.50 Published on Web 04/28/2004
2004 American Chemical Society
by Albemarle Corporation (7). Its applications are the same as for BDE209 (i.e., as an additive flame retardant in different types of plastics and textiles). In Europe, it is commercialized as a BFR that meets the German Dioxin ordinances (7, 8). In contrast to BDE209, it produces no polybrominated dibenzop-dioxins and only minor quantities of 2,3,7,8-tetrabromodibenzo-p-furan under pyrolysis conditions (8, 9). The oral toxicity of DeBDethane in rats was found to be low (10). The authors suggest that it may be due to poor bioavailability of the compound. DeBDethane has a molecular weight of 971.2 g/mol and an estimated log Pow of about 11 (11). The Swedish import of the BDE209 technical product was 15 t in 2001 (12). The estimated import of DeBDethane to Sweden in 2000 was less than that (personal communication, P. Ranken, Albemarle Corp.). In addition to the technical product, flame retardants are imported in prefabricated plastics and in treated products. For PBDEs, the treated products are estimated to represent more than 85% of the total imports to Sweden (13). To our knowledge, DeBDethane has never been identified in environmental samples. We decided to screen sewage sludge samples to evaluate whether this chemical is being released from the technosphere. Sewage sludge is frequently used as an indicator of the release of hydrophobic chemicals to the environment from a diverse range of sources including households, industry, and traffic. Following the discovery of the chemical in sewage sludge, we expanded the study to include sediment, one of the major reservoirs of hydrophobic chemicals in the natural environment. To establish whether DeBDethane is also present in the occupational environment, we collected and analyzed air in a dismantling facility for electronic equipment. Finally, we analyzed insulating foam to gain more information about the sources of this chemical.
Materials and Methods Chemicals. The technical DeBDethane product, SAYTEX 8010, (Lot no. 8721-21, Albemarle Corporation) was dissolved in acetone, tetrahydrofurane, and toluene, 20:30:50%. Organic solvents were of analytical grade (n-hexane, acetone, tetrahydrofurane, dichloromethane (DCM), and methanol (Merck, Darmstadt, Germany); diethyl ether and 2,2,4-trimethylpentane (Lab-Scan, Dublin, Ireland); and toluene (B&J, Fluka Chemie AG, Buchs, Switzerland)). Other chemicals used were sulfuric acid (98%, w/w, BDH, Poole, UK, and 98% Fisher Chemicals, Leicestershire, UK), phosphoric acid (pro analysi, Merck), sodium chloride (pro analysi, Riedel-de Haen, Seelze, Germany), ethanol (99.5%, Kemetyl, Haninge, Sweden), tetran-butylammonium hydrogen sulfate (TBA, Merck, Schuchardt, Germany), and sodium sulfite (Merck, Darmstadt). Silica gel (Kieselgel 60, 70-230 mesh) was obtained from Merck. Dechlorane 603 (Occidental Chemicals, Dallas, TX) was used as an internal surrogate standard. Samples. The sewage sludge samples (collected in year 2000) were part of a Swedish survey of sewage sludges for brominated flame retardants that included 50 sewage treatment plants (STP) distributed all over Sweden (15). The STPs were chosen to be representative for Sweden with respect to plant size and geographic distribution (see also Figure 2). Plants serving industries that were believed to use BFRs were also included. The treatment plants were divided into three classes depending on the size of the plant in person equivalents (PE). The number of treatment plants in each of the three size classes was eight large STPs (>75 000 PE), six medium sized (20 000-75 000 PE), and 36 small (
