Bromine flame

Brominated Diphenyl Oxides. Brominated diphenyl oxides are prepared by the bromination of diphenyl oxide. They are often referred to as diphenyl ethers. Taken together, the class constitutes the largest volume of brominated flame retardants. They range ia properties from high melting sohds to hquids. They are used, as additives, ia virtually every polymer system. 

Decabrom has poor uv stabiUty ia styrenic resias and causes significant discoloration. The use of uv stabilizers can minimize, but not eliminate, this effect. For styrenic apphcations that require uv stabiUty, several other brominated flame retardants are more suitable. In polyolefins, the uv stabiUty of decabrom is more easily improved by the use of stabilizers. 

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. 

Ethylenebis(tetrabromophthalimide). The additive ethylenebis(tetrabromophthalimide) [41291 -34-3] is prepared from ethylenediamine and tetrabromophthabc anhydride [632-79-1]. It is a specialty product used ia a variety of appHcations. It is used ia engineering thermoplastics and polyolefins because of its thermal stabiUty and resistance to bloom (42). It is used ia styrenic resias because of its uv stabiUty (43). This flame retardant has been shown to be more effective on a contained bromine basis than other brominated flame retardants ia polyolefins (10). 

Bis(bexacbIorocycIopentadieno)cycIooctane. The di-Diels-Alder adduct of hexachlorocyclopentadiene [77 7 ] and cyclooctadiene (44) is a flame retardant having unusually good thermal stabiUty for a chlotinated aUphatic. In fact, this compound is comparable ia thermal stabiUty to brominated aromatics ia some appHcations. Bis(hexachlorocyclopentadieno)cyclooctane is usedia several polymers, especially polyamides (45) and polyolefins (46) for wire and cable appHcations. Its principal drawback is the relatively high use levels required compared to some brominated flame retardants. 

There are a relatively small number of producers of halogenated flame retardants, especially for brominated flame retardants, where three producers account for greater than 80% of world production. Table 10 gives estimates of the volumes of brominated and chlorinated flame retardants used worldwide. Volumes of flame retardants consumed in Japan have been summarized (61). Prices of halogenated flame retardants vary from less than 2.00/kg to as high as 13.00/kg. Cost to the user depends on the level of use of the specific flame retardant and other factors such as the use of stabilizers. 

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. 

Research sponsored by BFRIP regarding the use of brominated flame retardants shows that there is no evidence that the use of decabromodiphenyl oxide leads to any unusual risk. In addition, a study by the National Bureau of Standards (now National Institute of Science and Technology) showed that the use of flame retardants significantly decreased the ha2ards associated with burning of common materials under reaUstic fire conditions (73). Work ia Japan confirms this finding (74). 

Phosphorus -bromine flame retardant synergy was demonstrated in a 2/1 polycarbonate/polyethylene blend. These data also show phosphorus to be about ten times more effective than bromine in this blend. Brominated phosphates, where both bromine and phosphorus are in the same molecule, were also studied. In at least one case, synergy is further enhanced when both phosphorus and bromine are in the same molecule as compared with a physical blend of a phosphorus and a bromine compound. On a weight basis, phosphorus and bromine in the same molecule are perhaps the most efficient flame retardant combination. The effect of adding an impact modifier was also shown. 

Table 1. Oxygen Index of PET Fibers Containing Phosphorus or Bromine Flame Retardants ...

Table 2. Enhancement of Bromine Flame Retardancy by Antimony and Phosphorus in a PET Fiberl... 

Incineration of a collection of polymers with 10 different kinds of brominated flame retardants has been studied under standardized laboratory conditions using varying parameters including temperature and air flow. Polybrominated diphenyl ethers like the deca-, octa-, and pentabromo compounds yield a mixture of brominated dibenzofurans while burning in polymeric matrices. Besides cyclization, debromination/hydrogenation is observed. Influence of matrix effects and burning conditions on product pattern has been studied the relevant mechanisms have been proposed and the toxicological relevance is discussed. 

M. Freiberg, D.L. McAllister, C.J. Mazac, P. Ranken Analysis of Trace Levels of Polybrominated Dibenzo-p-dioxins and Dibenzofurans in Brominated Flame Retardants Presented on June 30, 1993 at Orgabrom 93 in Jerusalem. 

See report of European Brominated Flame Retardant Industry Panel, March 1992, Bruxelles. 

The use of aromatic brominated compounds as flame retardants has been a potential source of environmental contamination. Incomplete incineration of these compounds and wastes (plastics, textiles, oils etc...) containing brominated flame retardants caused formation of brominated/chlorinated dibenzodioxines (PBDDs/ PCDDs) and dibenzofurans (PCDFs/PBDFs) (refs. 1 - 4). 

Algal and cyanobacterial toxins Brominated flame retardants Disinfection by-products Gasoline additives... 

Canton, R.F., Sanderson, J.T., and Nijmeijer, S. et al. (2006). In vitro effects of brominated flame retardants and metabolites on CYP17 catalytic activity A novel mechanism of action Toxicology and Applied Pharmacology 216, 274—281. 

Potter, A.E., Jr., and Anagnostou, E., Reaction order in the hydrogen-bromine flame from the pressure dependence of quenching diameter, Proc. Comb. Inst., 7 347,1959. 

Hewlett-Packard Development Company, L.P. (2005) HP to Ehminate Brominated Flame Retardants from External Case Parts of AH New HP Brand Products. [Online - cited 24 April 2007] Available from URL http //www.hp.eom/hpinfo/newsroom/press/2005/051101a.html... 

Data on additive production are mostly absent in LCI databases. Some data are available for metals production and for bisphenol-A, but even for widely used additives such as phthalates and brominated flame retardants, production data are not available. 

Covaci A, Harrad S, Abdallah MAE, Ali N, Law RJ, Herzke D, de Wit CA (2011) Novel brominated flame retardants a review of their analysis, environmental fate and behaviour. 

In addition, the concern about e-waste not only focuses on its vast quantity generated daily, but also more on the need to handle the toxic chemicals embedded in it. It is well known that e-waste contains lead, beryllium, mercury, cadmium (Cd), and brominated flame retardants (BFRs) among other chemical materials [3]. Furthermore, highly toxic chemicals such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDD/Fs) can be formed during the recycling process [4]. 

Shi T, Chen SJ, Luo XJ, Zhang XL, Tang CM, Luo Y, Ma YJ, Wu JP, Peng XZ, Mai BX (2009) Occurrence of brominated flame retardants other than polybrominated diphenyl ethers in environmental and biota samples from southern China Chemosphere 74(7) 910-916. doi 10.1016/j. chemosphere.2008.10.047... 

Choi K-I, Lee S-H, Osako M (2009) Leaching of brominated flame retardants from TV housing plastics in the presence of dissolved humic matter. Chemosphere 74(3) 460-466. doi 10.1016/j. chemosphere.2008.08.030... 

Keywords Brominated flame retardants, E-waste, Substance Flow Analysis SFA, Informal Recycling, Waste Electric and Electronic Equipment WEEE... 

Tasaki T, Takasuga T, Osako M, Sakai S-i (2004) Substance flow analysis of brominated flame retardants and related compounds in waste TV sets in Japan. Waste Manag 24(6) 571-580... 

The importance of assessing human and environmental impacts caused by emissions of metals and brominated flame retardants (BFRs) has been growing in... 

DEPA (Danish Environmental Protection Agency) 1999 Brominated flame retardants, Project No. 494... 

PBDEs are a class of brominated flame retardants (BFRs) used in textiles, plastics and electronic products. The effects of BFRs are associated with three commercial mixtures of PBDEs decaBDE, octaBDE and pentaBDE. In laboratory animal experiments, the toxicity of PBDEs was linked to damage to liver function and,... 

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