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VetBooks.ir Chapter 52

Brominated Flame Retardants

and Perfluorinated Chemicals

Prasada Rao S. Kodavanti, Matthew C. Valdez and Nobuyoshi Yamashita

INTRODUCTION leading to exposure of animals and humans and contribut-
ing to negative health effects (Linares et al., 2015; Blum,
During the past several decades, concern has been raised
2010; Loganathan, 2012). The Stockholm Convention on
regarding exposure and harmful health effects of synthetic
persistent organic pollutants (POPs) included some of the
organohalogen compounds, especially chlorine-containing
PBDEs and PFCs in the POPs list (Stockholm Convention
compounds such as chlorinated pesticides and polychlori-
Secretariat, 2010). Although the production and use of
nated biphenyls (PCBs) in domestic animals, wildlife,
PBDEs and PFCs are restricted, environmental contami-
and humans (Kodavanti et al., 2008, 2014; Loganathan
nation and harmful effects to animals and humans con-
and Masunaga, 2015). There is mounting evidence that
tinue. In this chapter, the historical background of BFRs
bromine- and fluorine-containing organohalogens are
and PFCs, physicochemical properties, exposure, pharma-
emerging as new pollutants that pose a threat on the
cokinetics, mechanism of action, and effects are discussed
global scale for present and future adverse health effects
with emphasis on domestic and pet animals.
in animals and humans (Roth and Wilks, 2014; Shaw and
Kannan, 2009; Shaw et al., 2010; Tanabe and Minh,
2010). Polybrominated diphenyl ethers (PBDEs) along BACKGROUND
with brominated bisphenols and cyclododecanes are three
major groups of chemicals of brominated flame retardants Of the brominated compounds still on the market, bromi-
(BFRs) predominantly used in numerous industrial and nated bisphenols, diphenyl ethers, and cyclododecanes are
consumer products to make these materials more fire three major classes that are still produced in large
resistant (Alaee et al., 2003; Blum, 2010). The general volumes (Fig. 52.1; Shaw and Kannan, 2009). It is esti-
chemical formula for PBDEs is C 12 H 10 x Br x O, and mated that more than one million metric tons of PBDEs
molecular weight ranges from 233 to 943. have been produced. Although the manufacture of penta-
Perfluorinated compounds (PFCs) such as perfluorooc- and octa-bromo mixtures has ceased, the production of
tane sulfonate/sulfonic acid (PFOS) and related com- decabromodiphenyl ether (decaBDE) continues in some
pounds are used as surfactants and have a wide range of countries (Guo et al., 2011). DecaBDE was banned in
industrial and commercial applications. The chemical for- Sweden and followed by partial bans in four US states
mula for PFOS is C 8 HF 17 O 3 S, and its molecular weight (Washington, Maine, Oregon, and Vermont) in 2007, the
is 500. The structures of selected PBDEs and PFCs are European Union in 2008, and Canada in 2009. The
shown in Figs. 52.1 52.3. Unlike chlorinated compounds REACH (Registration, Evaluation, Authorization, and
such as DDT (1,1,1-trichloro-2,2-bis[p-chlorophenyl]- Restriction of Chemical Substances) program in the
ethane) and other pesticides (hexachlorobenzene, hexachlor- European Union announced in February 2011 the ban of
ocyclohexanes, etc.) that are used as agricultural/public hexabromocyclododecane (HBCD) used with all polysty-
health insecticides, use of BFRs and/or PFCs has never rene in building insulation (REACH, 2011). In general,
resulted in direct exposure to farm, domestic and/or pet PBDEs and other brominated and chlorinated flame
animals. However, due to their unique physicochemical retardants in use are HBCD, decabromodiphenyl ether,
and biochemical properties, both BFRs and PFCs persist tetrabromobisphenol-A (TBBPA), tris(1-chloro-2-propyl)-
and pervade every component of the global ecosystem, phosphate, tris(2-chloroethyl)-phosphate, and Dechlorane

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