HEXABROMOCYCLODODECANE

Hexabromocyclododecane is white crystals and have two isomers with the melting point of low melting point type being 167-168 ℃ and high melting point type is 195-196 ℃. 
Hexabromocyclododecane has a good stability upon heat and ultraviolet light.
Hexabromocyclododecane is a brominated flame retardant that is widely used to reduce the flammability of materials such as polystyrene foam, textiles, and certain plastics.

CAS Number: 3194-55-6

Synonyms: SAYTEX HBCD, PYROVATEX 3887, DTXSID8025383, 5I9835JO3M, DTXCID601518531, 247-148-4, 25637-99-4, Cyclododecane, hexabromo-, HBCDD, Hexabromocyclododecane, 1,3,5,7,9,11-hexabromocyclododecane, 1093632-34-8, Hexabromocyclododecane (Mixture of Diastereomers), Hexabromocyclododecane (Mixture of α-Hexabromocyclododecane, β-Hexabromocyclododecane, γ-Hexabromocyclododecane, 1,2,5,6,9,10-Hexabromocyclododecane, and Hexabromocyclododecane (Undefined)), SCHEMBL942763, DTXSID20891513, LEOCKULGXOQRTQ-UHFFFAOYSA-N, NS00134712 

Hexabromocyclododecane is an additive flame retardant, meaning it is physically mixed into products rather than chemically bound, which allows it to migrate into the environment over time.
Hexabromocyclododecane is a persistent organic pollutant because it does not easily break down in nature, and it can accumulate in living organisms, particularly in fatty tissues. 
Hexabromocyclododecane has been detected in soil, water, air, and even in remote regions far from where it was used, showing its ability to travel long distances.

Exposure to Hexabromocyclododecane is associated with potential risks to human health and the environment, including endocrine disruption, developmental toxicity, and adverse effects on wildlife, especially in aquatic ecosystems. 
Due to these concerns, its production and use have been restricted or banned in many countries under international agreements like the Stockholm Convention on Persistent Organic Pollutants.
Hexabromocyclododecane is a bromoalkane consisting of cyclododecane bearing six bromo substituents at positions 1, 2, 5, 6, 9 and 10. 

Hexabromocyclododecane has a role as a neurotoxin, a persistent organic pollutant and a xenobiotic. 
It is a bromoalkane, a bromohydrocarbon and a brominated flame retardant.
Hexabromocyclododecane is a brominated flame retardant. It consists of twelve carbon, eighteen hydrogen, and six bromine atoms tied to the ring. 

Its primary application is in extruded (XPS) and expanded (EPS) polystyrene foam used as thermal insulation in construction. 
Other uses are upholstered furniture, automobile interior textiles, car cushions and insulation blocks in trucks, packaging material, video cassette recorder housing, and electric and electronic equipment. 
According to UNEP, "HBCD is produced in China, Europe, Japan, and the USA. 

The last known current annual production is approximately 28,000 tonnes per year.
The main share of the market volume is used in Europe and China" (figures from 2009 to 2010).
Due to its persistence, toxicity, and ecotoxicity, the Stockholm Convention on Persistent Organic Pollutants decided in May 2013 to list hexabromocyclododecane in Annex A to the convention with specific exemptions for production and use in expanded polystyrene and extruded polystyrene in buildings. 

Because HBCD has 16 possible stereo-isomers with different biological activities, the substance poses a difficult problem for manufacture and regulation. 
Hexabromocyclododecane is synthesized via the bromination of cyclododecatriene.
Hexabromocyclododecane is a brominated flame retardant. 

Hexabromocyclododecane is used in the textile industry and polystyrene foam manufacturing. 
Electrochemical reduction of HBCD at carbon and silver cathodes has been studied using cyclic voltammetry and controlled-potential electrolysis.
Hexabromocyclododecane was used to compare the efficiency of different advanced extraction techniques for the recovery of brominated flame retardants from styrenic polymers. 

Hexabromocyclododecane was used to study the kinetics of the thermal and photolytic segregation of HBCD using HPLC.
Hexabromocyclododecane, which has the molecular formula C12H18Br6 (HBCD), is a brominated flame retardant. 
Brominated flame retardants are organic compounds containing bromine that slow the ignition and spread of fire.

Hexabromocyclododecane was found primarily in expanded (EPS) and extruded (XPS) polystyrene foam used as an insulation material in the building industry (approximately 99% of its historical use). 
There were also a number of other minor uses as a flame retardant, such as in textiles used for upholstered furniture and upholstered seating in transportation, and in wall coverings and draperies. 
Hexabromocyclododecane was also used in some glues, paints, adhesives and polymers contained in electronic equipment. 

The only known intentional use of HBCD in products in Canada is within the automotive sector. 
Although, Hexabromocyclododecane may also be present in products made from recycled plastics including toys.
Hexabromocyclododecane by Oceanchem Group acts as a flame retardant. 

Hexabromocyclododecane contains a high amount of alicyclic bromine. 
Hexabromocyclododecane offers low melting point and high solubility in common solvents. 
Its high bromine content allows reduced loadings and its low melting point provides melt processability, resulting in minimal effect on the mechanical properties of formulated systems.

Exhibits high efficiency at low usage levels. 
Hexabromocyclododecane is possible to achieve transparent flame retardant formulations with HBCD flame retardant. 
It can be used without the addition of Sb2O3 material. 

Compatible with expanded polystyrene (EPS) foam, extruded polystyrene foam (XPS). 
Hexabromocyclododecane is recommended for building insulation and textiles.
Hexabromocyclododecane is a brominated flame retardant found world-wide in the environment and wildlife. 

Human exposure is evidenced from its presence in breast milk, adipose tissue and blood. 
It bioaccumulates and biomagnifies in the food chain. 
Hexabromocyclododecane persists and is transported long distances in the environment, and highly toxic to aquatic organisms. 

Hexabromocyclododecane also presents potential human health concerns based on animal test results indicating potential reproductive, developmental and neurological effects. 
For these reasons, the Environmental Protection
Hexabromocyclododecane intends to consider initiating action under the Toxic Substances Control Act to address the manufacturing, processing, distribution in commerce, and use of HBCD. 

Melting point: 188-191 °C
Boiling point: 505.2±50.0 °C(Predicted)
Density: 2.145±0.06 g/cm3(Predicted)
solubility: acetone: soluble25mg/mL, clear, colorless to light yellow
BRN: 1911324
InChI: InChI=1S/C12H18Br6/c13-7-1-2-8(14)10(16)5-6-12(18)11(17)4-3-9(7)15/h7-12H,1-6H2
InChIKey: DEIGXXQKDWULML-UHFFFAOYSA-N
SMILES: C1(Br)CCC(Br)C(Br)CCC(Br)C(Br)CCC1Br

Hexabromocyclododecane is a brominated flame retardant. 
It is used in the textile industry and polystyrene foam manufacturing. 
Electrochemical reduction of HBCD at carbon and silver cathodes has been studied using cyclic voltammetry and controlled-potential electrolysis.

Halide fire retardant is a kind of commonly-used organic fire retardants. 
The order of efficacy on fire retardancy for halogen element is I> Br> Cl> F. Because of that the C-F bond is very stable and is difficult to be broken down, so it has a poor fire-retardant effect. 
Moreover, owing to the poor thermal stability of the sulfonated, therefore, the industry usually applies chloride or bromide as the preferred fire retardant. 

The order of the fire-retardant effect of different kinds of organic compounds is that: aliphatic> cycloaliphatic> aromatic. 
However, the aliphatic compound has a poor thermal stability with the processing temperature should not exceed 205 ℃. 
In contrast, the thermal stability of the aromatic is relative good with the processing temperatures being up to 315 ℃. 

For the fire-retardant halide, they usually have relative high halogen content. 
Common halide fire retardants are as follows:
Chlorinated paraffin is made from the direct chlorination of wax. 

Hexabromocyclododecane has a good chemical stability with low cost and a relative wide application. 
It is often used in combination with antimony trioxide.
Full kelevan decane is generally produced by as following: first chloride the cyclopentadiene to yield hexachlorocyclopentadiene; then further go through dimerization under the catalysis of anhydrous aluminum chloride to obtain the final product.

Hexabromocyclododecane belongs cycloaliphatic class fire-retardant and is mainly applied to the fire retardancy in polypropylene, polystyrene and polypropylene fibers. 
Hexabromocyclododecane is made as following: first put butadiene for trimerization, to first make cyclododecyl-1, 5, 9-triene, and then further have addition reaction with bromine in the carbon tetrachloride solution to obtain the 1, 2, 5, 6, 9, 10-Hexabromocyclododecane.
Hexabromocyclododecane is produced from the bromination reaction of benzene with bromine in the tetrachloride solution with iron and sulfur as the catalyst. 

Hexabromocyclododecane is usually mixed with antimony trioxide.
The current applied brominates fire-retardants include mainly tetrabromoethane, tetrabromo phenol disulfide, decabromodiphenyl ether, decabromodiphenyl, isocyanate-tris (2,6-dibromopropyl) ester, 2, 2-[4-(2,3-dibromopropyl-3,5-dibromophenyl] propane, hexabromocyclododecane decane, hexabromobenzene, tetrabromobisphenol A, octabromodiphenyl ethers, tetrabromodiphenyl ether, poly-dibromo-phenylene oxide, bis (tribromophenoxy) ethane, tribromophenol, ethylene bis tetrabromophthalimide dicarboxamide, pentabromobenzyl polyacrylate and so on. 

They respectively can be applied to plate of integrated circuit, unsaturated polyester, epoxy resin, polystyrene resin, chloroprene rubber, styrene-butadiene rubber, natural rubber, polyester resins, polypropylene, polyethylene wires, polyurethane, fiber, ABS resin, nylon, polybutylene terephthalate and so on.
Put into the polystyrene (PS) (fire retardants), Hexabromocyclododecane (fire retardants) and talc from the extruder into the feed section, and pump into the remaining foaming agent between the compression section and metering section to obtain a high compression-resistant foam sheet with a density of 34.7kg/m3 and water absorption of 0.09%.

Hexabromocyclododecane enhances the diet-induced body weight gain and metabolic dysfunction via disruption of lipid and glucose homeostasis in mice fed normal diet or high-fat diet.
Hexabromocyclododecane's toxicity and its harm to the environment are current sources of concern. 
Hexabromocyclododecane can be found in environmental samples such as birds, mammals, fish, and other aquatic organisms as well as soil and sediment.

On this basis, on 28 October 2008, the European Chemicals Agency decided to include HBCD in the SVHC list, Substances of Very High Concern, within the Registration, Evaluation, Authorisation and Restriction of Chemicals framework. 
On 18 February 2011, Hexabromocyclododecane was listed in Annex XIV of REACH and hence is subject to Authorisation. 
Hexabromocyclododecane can be used until the so-called “sunset date” (21 August 2015). 

After that date, only authorized applications will be allowed in the EU.
Hexabromocyclododecane has been found widely present in biological samples from remote areas and supporting pieces of evidence for its classification as Persistent, Bioaccumulative, and Toxic (PBT) and undergoes long-range environmental transportation.
In July 2012, an EU-harmonized classification and labeling for HBCD entered into force. 

Hexabromocyclododecane has been classified as a category 2 for reproductive toxicity.
Since August 2010 hexabromocyclododecanes are included in the EPA's List of Chemicals of Concern.
Japan was the first country to implement a ban on the import and production of Hexabromocyclododecane effective in May 2014. 

The United States EPA began the process of regulating Hexabromocyclododecane in 2020 releasing it final evaluation of the chemicals and confirmed its health and environmental risks in 2022.
Because Hexabromocyclododecane has 16 possible stereo-isomers with different biological activities, the substance poses a difficult problem for manufacture and regulation.
The Hexabromocyclododecane commercial mixture is composed of three main diastereomers denoted as alpha (α-HBCD), beta (β-HBCD), and gamma (γ-HBCD) with traces of others. 

A series of four published in vivo mice studies were conducted between several federal and academic institutions to characterize the toxicokinetic profiles of individual Hexabromocyclododecane stereoisomers. 
The predominant diastereomer in the Hexabromocyclododecane mixture, γ-HBCD, undergoes rapid hepatic metabolism, fecal and urinary elimination, and biological conversion to other diastereomers with a short biological half-life of 1–4 days. 
After oral exposure to the γ-HBCD diastereomer, β-HBCD was detected in the liver and brain, and α-HBCD and β-HBCD was detected in the fat and feces with multiple novel metabolites identified - monohydroxy-pentabromocyclododecane, monohydroxy-pentabromocyclododecene, dihydroxy-pentabromocyclododecene, and dihydroxy-pentabromocyclododecadiene.

In contrast, α-HBCD is more biologically persistent, resistant to metabolism, bioaccumulates in lipid-rich tissues after a 10-day repeated exposure study, and has a longer biological half-life of up to 21 days; only α-HBCD was detected in the liver, brain, fat and feces with no stereoisomerization to γ-HBCD or β-HBCD and low trace levels of four different hydroxylated metabolites were identified.

Developing mice had higher Hexabromocyclododecane tissue levels than adult mice after exposure to either α-HBCD or γ-HBCD indicating the potential for increased susceptibility of the developing young to HBCD effects.
The reported toxicokinetic differences of individual HBCD diastereoisomers have important implications for the extrapolation of toxicological studies of the commercial HBCD mixture to the assessment of human risk.

Uses:
Hexabromocyclododecane can be used in smoldering, for polystyrene foamed plastics, polypropylene and polyester, acrylic, polypropylene and other fabrics as smoldering finishing agent.
Hexabromocyclododecane is mainly used for thermoplastic and thermosetting polymers which have fire retardant requirements. 
It is particularly suitable for extrusion of foaming polystyrene.

It is used for the fire-retardant polystyrene of polypropylene plastics and fibers. 
Hexabromocyclododecane can also be used for the fire retardancy of finishing and leather double-sided coat after the fire-retardancy of polyester fabric. 
When used as additive fire retardants, it is especially suitable for polystyrene, unsaturated polyester, polycarbonate, polypropylene, synthetic rubber or the like.

Hexabromocyclododecane is primarily used as a flame retardant in expanded polystyrene (EPS) and extruded polystyrene (XPS) foam, which are commonly found in building and construction materials for insulation purposes. 
By reducing the flammability of these foams, it helps improve fire safety in residential, commercial, and industrial buildings, especially in walls, roofs, and floors.
Hexabromocyclododecane is also used in the production of high-impact polystyrene and textile coatings to enhance their fire resistance, making it valuable in applications such as furniture upholstery, vehicle interiors, and electrical housings. 

Because Hexabromocyclododecane is an additive flame retardant, it can be easily incorporated into different polymer matrices during manufacturing without requiring chemical bonding.
In the past, Hexabromocyclododecanewas widely used due to its effectiveness and relatively low cost, making it a preferred choice for manufacturers seeking to meet fire safety regulations.
However, due to its persistence, bioaccumulation, and potential toxicity, its use has been increasingly restricted, and safer alternatives are now being promoted for most of these applications.

Hexabromocyclododecane was used to compare the efficiency of different advanced extraction techniques for the recovery of brominated flame retardants from styrenic polymers. 
It was used to study the kinetics of the thermal and photolytic segregation of HBCD using HPLC.
In Australia, Hexabromocyclododecane was used as an additive flame retardant and was added to expanded polystyrene (EPS) components such as baby car seats, packaging, bean bag fill and EPS products used for the construction industry. 

Hexabromocyclododecane is not manufactured in Australia but has previously been imported as liquid dispersions for formulation into articles.
Hexabromocyclododecane has also been used in coatings for backcoated fabrics and textiles to improve their flame resistance, especially in products like curtains, upholstery, and automobile fabrics where fire safety standards are strict. 
In these applications, it provides an effective barrier to ignition and slows down the spread of flames, giving occupants more time to react in case of a fire.

Additionally, Hexabromocyclododecane has been applied in certain adhesives and sealants where both structural integrity and fire safety are important, such as in construction or transportation industries. 
It was also occasionally used in electrical and electronic equipment housings to meet flammability requirements, particularly for plastic parts in appliances and devices.

Its effectiveness as a flame retardant is due to the high bromine content, which interferes with the combustion process by releasing bromine radicals that quench free radicals in flames.
Despite these benefits, many industries have transitioned to alternative flame retardants or non-flammable materials because Hexabromocyclododecane can leach out of products, contaminate dust and water, and ultimately accumulate in humans and wildlife, leading to long-term environmental and health risks.

Safety Profile:
Hexabromocyclododecane poses several hazards to both human health and the environment due to its chemical properties and persistence. 
It is considered a persistent organic pollutant (POP), meaning it does not easily degrade in the environment and can travel long distances through air and water. 
Because it is lipophilic, it accumulates in the fatty tissues of living organisms and biomagnifies through the food chain, which means that higher concentrations can be found in predators, including humans.

For human health, exposure to Hexabromocyclododecane can occur through inhalation of contaminated dust, ingestion of food, or contact with treated materials, especially in indoor environments where it is used in insulation or textiles. 
Studies suggest that it may act as an endocrine disruptor, affecting thyroid hormone regulation and reproductive health. 
It has also been associated with developmental toxicity, potentially impacting brain development, behavior, and learning in children exposed before or after birth.