OCTABROMODIPHENYL

Octabromodiphenyl Oxide. Octabromodiphenyl oxide [32536-52-0] (OBDPO) is prepared by bromination of diphenyl oxide. The degree of bromination is controlled either through stoichiometry (34) or through control of the reaction kinetics (35). The melting poiat and the composition of the commercial products vary somewhat. OBDPO is used primarily ia ABS resias where it offers a good balance of physical properties. Poor uv stabiUty is the primary drawback and use ia ABS is being supplanted by other brominated flame retardants, primarily TBBPA. 

The Brominated Flame Retardants Industry Panel (BFRIP) was formed ia 1985 within the Flame Retardant Chemicals Association (FRCA) to address such concerns about the use of decabromodiphenyl oxide. Siace 1990 the BFRIP has operated as a Chemical Self-Funded Technical Advocacy and Research (CHEMSTAR) panel within the Chemical Manufacturers Association (CMA) (64). As of 1993, members of BFRIP are Ak2o, Amerihaas (Dead Sea Bromine Group), Ethyl Corp., and Great Lakes Chemical. Siace its formation, BFRIP has presented updates to iadustry on a regular basis (65,66), and has pubhshed a summary of the available toxicity information on four of the largest volume brominated flame retardants (67,68) tetrabromo bisphenol A, pentabromodiphenyl oxide, octabromodiphenyl oxide, and decabromodiphenyl oxide. This information supplements that summarized ia Table 11. 

Proper selection of plastic matrix fire retardants and property enhancers offers acceptable combinations of impact properties and heat-distortion temperature (HDT) values for fire retardant plastics. This can be demonstrated by fire retardant styrenics. Fire retardant enhancers have special interest as property enhancers for example the addition of a highly flammable material such as ethylene propylene diene terpolyer (EPDM), dramatically improves the bromine efficiency of octabromodiphenyl oxide in ABS by increasing char-forming without changing the Sb-Br reaction. 

Impact energy can be further improved by the use of impact modifiers. In this approach the combination of impact improvement and fire retardant enhancing is of special interest (ref. 5). Figure 5 demonstrates this effect in ABS flame-retarded with commercial FR-1208 (octabromodiphenyl oxide) and with the proprietary FR-T6385. 

There is a huge variety of PBDEs considering that there might be from one to ten bromine atoms bound to the diphenyl ether molecule. Among all the PBDEs, the commercial mixtures of decabromodiphenyl ether (deca-BDE), octabromodiphenyl ether (octa-BDE) and pentabromodiphenyl ether (penta-BDE) are the products that are most found in the environment. Related to octa-BDE and penta-BDE mixtures, their commercial use was banned in the European Union in 2004 and that year their leading manufacturers in North America stopped producing them on a voluntary basis [2], Regarding the deca-BDE mixture, since July 2008, its use has been... 

Octabromodiphenyl ether, physical properties of, 4 355t Octabromodiphenyl oxide, 11 455 Octachlorocyclotetraphosphazene, 19 55 Octacosanoic acid, physical properties, 5 30t... 

The replacement of established chemistries with newer ones is one of the classic drivers of change in the chemical industry. One of the current hotbeds of this kind of change is the replacement of brominated flame retardants in polymer formulations. The brominated flame retardants under the most scrutiny have been polybrominated diphenyl ethers, particularly penta- and octabromodiphenyl ether, which have been shown to be persistent in the environment and to bioaccumulate. Great Lakes Chemical is voluntarily phasing out penta- and octa-BDEs by the end of next year. The phaseout is made possible by the clean bill of health granted by EPA for Firemaster 550, a replacement for penta-BDE in flexible PU applications. BRG Townsend claims the phaseout of penta-BDE and octa-BDE is not as earth shattering as would be an exit from deca-BDE, a styrenics additive that is produced in the highest volume of the PBDEs. 

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)). 

These results indicate that the first step in BDE-209 photodegradation is the loss of one bromine atom to form nonabromodiphenyl ether congeners, followed by the subsequent formation of octabromodiphenyl ethers. 

Pentabromodiphenyl ether Octabromodiphenyl ether Decabromodiphenyl ether... 

Octabromodiphenyl ether octabromodiphenyl oxide octabromobiphenyl oxide benzene, octabromo derivative phenyl ether, octabromo derivative... 

DeBDE=Decabromodiphenyl ether HpBDE=Heptabromodiphenyl ether HxBDE=Hexabromodiphenyl ether NoBDE=Nonabromodiphenyl ether OcBDE=Octabromodiphenyl ether PBDE=Polybrominated diphenyl ether PeBDE=Pentabromodiphenyl ether TeBDE=Tetrabromodiphenyl ether TrBDE=Tribromodiphenyl ether... 

Resin/polymer/ substrate Example of final product Pentabromo-dlphenyl ether Octabromodiphenyl ether Decabromodiphenyl ether... 

ATSDR has derived an MRL of 0.03 mg/kg/day for acute-duration oral exposure to PBDEs. The acute oral MRL is based on a NOAEL of 1 mg/kg/day for reduced serum levels of thyroid T, hormone in fetal rats that were exposed to octabromodiphenyl ether on days 4-20 of gestation (Zhou et al. 2002). ATSDR also derived an MRL of 0.007 mg/kg/day for intermediate-duration oral exposure to PBDEs. The intermediate oral MRL is based on a minimal LOAEL of 2 mg/kg/day for liver effects in rats that were exposed to pentabromodiphenyl oxide for 90 days (WIL Research Laboratories 1984). 

Reference doses (RfDs) for decabromodiphenyl ether, octabromodiphenyl ether, and pentabromodiphenyl ether are IxlO, 3x10, and 2x10 mg/kg/day, respectively (IRIS 2002). 

Decabromodiphenyl ether Octabromodiphenyl ether Pentabromodiphenyl ether... 

Decabromobiphenyl Decabromodiphenyl ether Hexabromo-1, T-biphenyl Octabromobiphenyl Octabromodiphenyl ether p-Bromodiphenyl ether Pentabromodiphenyl ether... 

Tolybrominated biphenyls category includes decabromobiphenyl (CAS 13654-09-6) decabromodiphenyl ether (CAS 1163-19-5) hexabromobiphenyl (CAS 59080-40-9) hexabromo-1,1 -biphenyl (CAS 36355-01-8) hexabromodiphenyl ether (CAS 36483-60-0) nonabromodiphenyl ether (CAS 63936-56-1) octabromobiphenyl (CAS 27858-07-7) octabromobiphenyl (CAS 61288-13-9) octabromodiphenyl ether (CAS 32536-52-0) p-bromodiphenyl ether (CAS 101-55-3) p,p -dibromodiphenyl ether (CAS 2050-47-7) pentabromodiphenyl ether (CAS 32534-81-9) polybrominated biphenyl (CAS 59536-65-1) polybrominated biphenyl mixture (CAS 67774-32-7) tetrabromodiphenyl ether (CAS 40088-47-9) and tri bromodiphenyl ether (CAS 49690-94-0). 

Dow Chemical Company. 1971. Results of 30 day dietary feeding studies on octabromodiphenyl SA-1902 and decabromodiphenvl oxide SA-1892.1. Submitted to U S. EPA under TSCA Section 8D, Fiche no. OTS0522265. 

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