Hexabromobenzene

It can be prepared by the reaction of benzene with 6 equivalents of bromine (Br₂) in the presence of heat and UV light:{{cn|date=January 2025}}

:{{chem2 | C6H6 + 6 Br2 -> C6Br6 + 6 HBr }}

The reaction produces six equivalents of hydrogen bromide.

Hexabromobenzene has seen use in high voltage capacitors as a flame retardant.{{cite patent |country=US |number=6909590 |status=Grant |gdate=2005-06-21 |fdate=2005-04-07 |pubdate=2004-08-09 |title=High voltage capacitor and magnetron |inventor=Tsukasa Sato, Isao Fujiwara, Makoto Morita, Kenichi Horikawa |assign1=TDK Corp}}

Hexabromobenzene finds extensive use as a fire retardant additive in a range of materials including plastics, paper, and electrical goods, where it serves as a top-tier flame retardant. It was introduced to replace traditional organobromine fire retardants such as polybrominated derivatives of diphenyl ethers and biphenyls.{{cite journal |doi=10.1016/j.watres.2021.117168 |title=Occurrence, bioaccumulation, fate, and risk assessment of novel brominated flame retardants (NBFRS) in aquatic environments — A critical review |date=2021 |last1=Hou |first1=Rui |last2=Lin |first2=Lang |last3=Li |first3=Hengxiang |last4=Liu |first4=Shan |last5=Xu |first5=Xiangrong |last6=Xu |first6=Yiping |last7=Jin |first7=Xiaowei |last8=Yuan |first8=Yong |last9=Wang |first9=Zijian |journal=Water Research |volume=198 |pmid=33962238 |bibcode=2021WatRe.19817168H }} With a high melting point of 327 °C and a high bromide content of 86%, HBB significantly enhances the fire safety of these materials.{{Cite web |title=Premium 98% Pure Hexabromobenzene for Enhanced Fire Resistance & Versatility |url=https://procure-net.com/product/hexabromobenzene/ |access-date=2024-02-11 |website=Procurenet Limited |language=en}} Iits widespread application also leads to its dispersion in the environment.

Hexabromobenzene was used in a study investigating its metabolic fate in female rats, wherein the substance was orally administered at doses of 16.6 mg/kg body weight every other day for a span of 2 weeks. Analysis of the rats' excreta revealed the presence of various metabolites, including unchanged HBB, pentabromobenzene, as well as oxygen- and sulfur-containing compounds.{{Cite journal |last1=Koss |first1=G |last2=Doring |first2=H |last3=Wurminghausen |first3=B |last4=Koransky |first4=W |date=November 1982 |title=Metabolic fate of hexabromobenzene in rats |url=https://linkinghub.elsevier.com/retrieve/pii/037842748290011X |journal=Toxicology Letters |language=en |volume=14 |issue=1–2 |pages=69–77 |doi=10.1016/0378-4274(82)90011-X|url-access=subscription }}

Hexabromobenzene poses significant dangers due to its toxicity profile as classified by the GHS (Globally Harmonized System of Classification and Labeling of Chemicals). Classified as GHS07, HBB exhibits acute toxicity via oral, dermal, and inhalation routes, categorizing it under category 4 for this hazard. Additionally, it induces skin and eye irritation, classified under category 2 for both. Moreover, HBB is known to cause skin sensitization (category 1) and specific target organ toxicity upon single exposure (category 3), with the respiratory system being the primary target organ.{{Cite web |date=August 27, 2023 |title=Hexabromobenzene |url=https://www.sigmaaldrich.com/US/en/product/aldrich/107131 |url-status=live |archive-url=https://www.sigmaaldrich.com/US/en/sds/aldrich/107131?userType=anonymous |archive-date=January 13, 2024 |access-date=February 3, 2024 |website=Sigma-Aldrich}}

The acute toxicity of brominated benzenes decreases with an increase in the number of bromine atoms in the molecule.{{Cite journal |last1=Peng |first1=Anping |last2=Gao |first2=Hu |last3=Wang |first3=Huimin |last4=Wang |first4=Yi |last5=Chen |first5=Zeyou |date=July 2023 |title=Influence of organic cosolvents on hexabromobenzene degradation in solution by montmorillonite-templated subnanoscale zero-valent iron |url=https://linkinghub.elsevier.com/retrieve/pii/S0013935123007788 |journal=Environmental Research |language=en |volume=229 |pages=115986 |doi=10.1016/j.envres.2023.115986|pmid=37100367 |bibcode=2023ER....22915986P |url-access=subscription }} However, the potential for necrotic changes varies based on the position of these bromine atoms within the molecule. There are severe health risks associated with HBB exposure, warranting careful handling and stringent safety measures in its use and management.

• Pentabromotoluene

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Category:Bromobenzenes