Flame retardant hexabromocyclododecane

Keywords Bioaccumulation, Bioavailability, Brominated flame retardants, Hexabromocyclododecane, Polybrominated diphenyl ether... 

Law, R.J., Bersuder, R, Allchin, C. R., Barry, J. (2006b) Levels of the flame retardants hexabromocyclododecane and tetrabromobisphenol A in the blubber of harbour porpoises (Phocoena phocoena) stranded orbycaught in the UK, with evidence for an increase in HBCD concentrations in recent years. Environ. Sci. TechnoL, 40 2177-2183. 

Morris, S., Bersuder, R, Allchin, C. R., Zegers, B., Boon, J. R, Leonards, R. E. G., de Boer, J. (2006) Determination of the brominated flame retardant, hexabromocyclododecane, in sediments and biota by liquid chromatography-electrospray ionisation mass spectrometry. TrAC, 25 343-349. 

Ema M, Fujii S, Hirata-Koizumi M et al (2007) Two-generation reproductive toxicity study of the flame retardant hexabromocyclododecane in rats. Reprod Toxicol 25 335-351 Eriksson P, Fischer C, Fredriksson A (2006) Poly-brominated diphenyl ethers, a group of brominated flame retardants, can interact with polychlorinated biphenyls in enhancing developmental neurobehavioral defects. Toxicol Sci 94 302-309 Eskenazi B, Chevrier J, Rauch SA et al (2013) In utero and childhood polybrominated diphenyl ether (PBDE) exposures and neurodevelopment in the CHAMACOS study. Environ Health Perspect 121 257-261... 

Phosphonium Salt—Urea Precondensate. A combination approach for producing flame-retardant cotton-synthetic blends has been developed based on the use of a phosphonium salt—urea precondensate (145). The precondensate is appUed to the blend fabric from aqueous solution. The fabric is dried, cured with ammonia gas, and then oxidized. This forms a flame-resistant polymer on and in the cotton fibers of the component. The synthetic component is then treated with either a cycUc phosphonate ester such as Antiblaze 19/ 19T, or hexabromocyclododecane. The result is a blended textile with good flame resistance. Another patent has appeared in which various modifications of the original process have been claimed (146). Although a few finishers have begun to use this process on blended textiles, it is too early to judge its impact on the industry. 

BFRs are one of the last classes of halogenated compounds that are still being produced worldwide and used in high quantities in many applications. In order to meet fire safety regulations, flame retardants (FRs) are applied to combustible materials such as polymers, plastics, wood, paper, and textiles. Approximately 25% of all FRs contain bromine as the active ingredient. More than 80 different aliphatic, cyclo-aliphatic, aromatic, and polymeric compounds are used as BFRs. BFRs, such as polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA), have been used in different consumer products in large quantities, and consequently they were detected in the environment, biota, and even in human samples [26, 27]. 

Due to their adverse health effects, several restrictions and bans have been imposed on the usage of polybrominated diphenyl ethers (PBDEs), namely the penta-, octa-, and deca-BDE formulations, in Europe, China, North America, and Japan (http //www. bsef.com). The restricted usage of these PBDEs increased the market demand for substitute brominated flame retardants (BERs) including hexabromocyclododecanes... 

Driffield M, Harmer N, Bradley E, Fernandes AR, Rose M, Mortimer D, Dicks P (2008) Determination of brominated flame retardants in food by LC-MS/MS diastereoisomer-specific hexabromocyclododecane and tetrabromobisphenol A. Food Addit Contamin... 

Saegusa Y, Fujimoto H, Woo GH, Inoue K, Takahashi M, Mitsumori K, Hirose M, Nishikawa A, Shibutani M (2009) Developmental toxicity of brominated flame retardants, tetrabromo-bisphenol A and 1,2,5,6,9,10-hexabromocyclododecane, in rat offspring after maternal exposure from mid-gestation through lactation. Reprod Toxicol 28 456-467... 

The term brominated flame retardant (BFR) incorporates more than 175 different types of substances, which form the largest class of flame retardants other classes are phosphorus-containing, nitrogen-containing, and inorganic flame retardants (Bimbaum and Sttaskal 2004). The major BFR substances in use today (depicted in Fig. 4.6) are tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and mixtures of polybrominated diphenyl ethers (PBDEs) (namely, deca-bromodiphenyl ether (DBDE), octabromodiphenyl ether (OBDE), and pentabro-modiphenyl ether (pentaBDE)). 

Following receipt of data the Commission drew up priority lists of substances that, on the basis of that data, were thought to have the potential to pose a risk of harm to human health or the environment. By the publication of the EU White Paper in 2001, four lists, containing a total of 141 substances, had been adopted by the relevant technical committee (CEC, 2001). The progress of these risk assessments was very slow. Risk assessment of hexabromocyclododecane (HBCD), for example, commenced in 1997 but was still not completed nine years later (ENDS, 2006). In 2006 around 16,700 tonnes of HBCD were produced every year for use as a flame retardant. It may have neurotoxic effects and interfere with the metabolism of thyroid hormone, but because risk assessment of it had not reached a conclusion there were no restrictions on its use. By 2006 final risk assessment reports were available for only about 70 substances (European Commission, 2006b) — less than 0.5 per cent of the 30,000 or so existing substances on the European market at quantities of above 1 tonne per annum. 

The RoHS procedure has now combined with European Union Registration, Evaluation, Authorisation and restriction of Chemicals (REACH), which is a new European Union Regulation (EC/2006/1907 of 18 December 2006). Four additional substances are listed that will be assessed as a priority, among these substances is hexabromocyclododecane, a brominated flame retardant widely used in expanded polystyrene for which no alternatives have been found so far. REACH addresses the production and use of chemical substances and their potential impacts on both human health and the environment it has been described as the most complex legislation in the Union s history and the most important in the last 20 years. It is the strictest law to date regulating chemical substances and will impact industries throughout the world. REACH entered into force in June 2007, with a phased implementation over the next decade. 

Other flame-retardants selected as priority chemicals for the EU Risk Assessment process included tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), tris(2-chloroethyl) phosphate (TCEP), tris (2-chloropropyl) phosphate (TCPP), tris(2-chloro-l-(chloromethyl)ethyl) phosphate (TDCP), and 2,2-bis(chloromethyl) trimethylene bis (bis(2-chloroethyl)phosphate) (V6). The flame-retardant synergist, antimony trioxide (Sb ), was also identified as a priority substance. Table 22.1 contains information on the EU Risk Assessments on the nine flame-retardants and one synergist. 

Figure 2.1 Chemical structures of major flame retardant compounds (a) polybrominated diphenyl ethers, (b) hexabromocyclododecane, (c) tetrabromobisphenol-A, (d) decabromo-dlphenyl ether (BDE209)...

Admon, S., Davis, J. W., Gonsior, S. J., Friederich, U., Hunziker, R. W., Ariano, J. M., Weiss, M. (2007) Environmental fate of hexabromocyclododecane (HBCD), the degradation pathway. In Proceedings of the 4th International Workshop on Brominated Flame Retardants, Amsterdam, The Netherlands, 24-27 April 2007 (unpaginated). 

Hexabromocyclododecane (HBCDD) is a flame retardant in polystyrene foams used in upholstered furniture and building insulation, with an estimated production of 16 700 tonnes... 

Another approach to durable flame retardant finishes for polyester is the use of highly brominated chemicals as topical finishes. One particularly useful material is hexabromocyclododecane (HBCD, Fig. 8.19). To achieve durable flame retardancy, fabric padded with 8 % of a dispersion of this water insoluble material must be heated above 190 °C or 375 °F to form a film of the flame retardant on the fibre surface."... 

Great Lakes CD-75P . [Great Lakes] Hexabromocyclododecane flame retardant for diennoplastic and thermoset polymers, textile treatments, latex binders, adhesives, unsat polyesters, and coatings. 

Cyclododeoane, 1,2,5,6,9,10-hexabromo- EINECS 221-695-9 Hexabromocyclododecane HSDB 6110 Saytex HBCD-LM. Low melting flame retardant Solid mpn 173-177 , Ethyl Corp. 

Tribromophenylallyl ether FR-913. Aromatic flame retardant for expandable PS synergist with hexabromocyclododecane. White to off-white crystal powder mp = 74-76" d = 2.20 LD50 (rat orl) > 5000 mg/kg (rbt der) > 2000 mg/kg. AmeriBrom Inc. Amerihaas Dead Sea Bromine. 

Brominated flame retardants (BFRs) are a structurally diverse group of compounds including aromatics, cyclic aliphatics, phenolic derivatives, ahphatics, and phthahc anhydride derivatives (Figure 31.3). The most common BFRs are tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDE), hexabromocyclododecane (HBCD), and polybrominated biphenyls (PBB). The primary use of TBBPA is as reactive additive in epoxy resin circuit boards, while decabromodiphenyloxide (DBDO) is primarily used in high impact polystyrene for electronic enclosures. PBDEs are typically used as the additive type of flame retardant in high impact polystyrene, acrylonitrile butadiene styrene, flexible polyurethane foam, textile coatings, wire and cable insulation and electrical connectors. 

Chem. Descrip. Hexabromocyclododecane CAS 3194-55-6 EINECS/ELINCS 221-695-9 Uses Flame retardant for low-dens, expandable and extruded PS foam, ciystal and high-impact PS, PP, PVC wire/cable, textiles, hot-melt adhesives, coatings... 

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