Tetrabrom(tetrabromphenyl)benzol

Soluble in methylene chloride and benzene

In water, 20-30 ug/kg at 25 °C

Not Classified

Danger

H350: May cause cancer [Danger Carcinogenicity]

P203, P280, P318, P405, and P501 (click each P-code to see the statement)

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

S - indicates a substance that is identified in a final Significant New Use Rule.

Restricted substance: Tetrabromo(tetrabromophenyl)benzene

Emergency medical treatment: see PCB-PBB; A skin, eye, and mucous membrane irritant; Mildly irritating to rabbit conjunctivae; Feeding studies with rats have demonstrated adverse histological changes to liver; No evidence of chloracne in 30 day study with rabbit ears; Not sensitizing to guinea pig skin; [HSDB] see Polybrominated biphenyls.

Not Classified

Acute toxicity (Oral) - Category 4

Carcinogenicity - Category 1B

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 349,000(SRC), determined from a structure estimation method(2), indicates that octabromobiphenyl will be immobile in soil(SRC). Volatilization of octabromobiphenyl from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.4X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 7.0X10-11 mm Hg(3), and water solubility, 0.030 mg/L(4). Octabromobiphenyl is not expected to volatilize from dry soil surfaces(SRC) based on its vapor pressure(3). Biodegradation data for octabromobiphenyl were not available(SRC, 2005). Biodegradation data on polybrominated biphenyls such as hexabromobiphenyl indicate these compounds are persistent in the environment, but may slowly be degraded under anaerobic conditions(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 349,000(SRC), determined from a structure estimation method(2), indicates that octabromobiphenyl is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.4X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 7.0X10-11 mm Hg(4), and water solubility, 0.030 mg/L(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from a log Kow of 5.53(5) and regression derived equation(7) suggests the potential for bioconcentration in aquatic organisms is low (SRC). Static bioconcentration studies conducted using fish exposed to 14C-labeled octabromobiphenyl for 48 hours indicate that this compound does not bioconcentrate(9). Octabromobiphenyl is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(8). Brominated biphenyls have been shown to undergo direct photolysis in solutions(8), suggesting that there is potential for direct photolysis in sunlit surface waters(SRC). Biodegradation data for octabromobiphenyl were not available(SRC, 2005). Biodegradation data on polybrominated biphenyls such as hexabromobiphenyl indicate these compounds are persistent in the environment, but may slowly be degraded under anaerobic conditions(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), octabromobiphenyl, which has a vapor pressure of 7.0X10-11 mm Hg at 28 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase octabromobiphenyl may be removed from the air by wet and dry deposition(SRC). Brominated biphenyls have been shown to undergo direct photolysis in solutions(3); however, it is unclear whether direct photolysis will occur for particulate phase octabromobiphenyl in the atmosphere.

The exact mechanism of toxicty of PBBs varies depending on the specific congener. The predominant interaction is believed to involve the aryl hydrocarbon receptor (AhR). PBBs bind to and activate the AhR, which in turn initiates the transcriptional upregulation of a number of genes, affecting biochemical and endocrine pathways, cell cycle regulation, morphogenesis, oxidative stress response, and various other processes. This results in the numerous toxic responses characteristic of PBBs. Some of the known induced genes include the cytochrome P-450-dependent monooxygenases CYP1A1 and CYP1A2. (L628)

Octabromobiphenyl was a minor constituent in the product Firemaster BP-6, which was accidentally substituted for a cattle nutrient in feed sent to a number of farms in Michigan in 1973(1). The disposal of contaminated feed, animal carcasses (poultry, dairy cattle, swine) and animal products such as meat, eggs, and dairy products was a source of octabromobiphenyl emitted to the environment(1).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for octabromobiphenyl can be estimated to be 349,000(SRC). According to a classification scheme(2), this estimated Koc value suggests that octabromobiphenyl is expected to be immobile in soil(SRC).

Octabromobiphenyl's former production and use as an additive in flame retardant materials(1), may have resulted in its release to the environment through various waste streams(SRC). Most octabromobiphenyl produced in the US was exported and US production was discontinued in 1979(2).

Fish (Salmo salar) fed octabromobiphenyl-contaminated food contained unidentified penta-, hexa-, and heptabromobiphenyls in addition to the octabromo biphenyls. It was not known whether the partially debrominated biphenyls were generated by the fish, or by the associated microflora.

PBBs can be absorbed via oral, inhalation, and dermal routes. Due to their lipophilic nature, PBBs, especially the highly brominated congeners, tend to accumulate in lipid-rich tissues such as the liver, adipose, skin, and breast milk. Certain PBB compounds are metabolized by the microsomal monooxygenase system catalyzed by cytochrome P-450 of the type induced by phenobarbital. The rate of metabolism may depends on the bromine substitution pattern. PBB congeners of low bromine content are transformed into hydroxylated derivatives that are predominately eliminated in the urine. Highly brominated congeners are either retained or excreted unchanged in the feces. (L628)

...Increased bromine concentrations were found in the liver and adipose tissue of rats exposed continuously to a commercial mixture of octabromobiphenyl for 15 weeks, suggesting that absorption had occurred. /Commercial mixture/

Rats being fed diets containing 1, 10, 100, or 1000 ppm octabromobiphenyl for 2 or 4 weeks showed dose-related accumulation of bromine in fat, liver, and muscle at levels > 10 ppm. Levels in the muscles were 3-4 times lower than that in the fat and liver. ... At 18 weeks after treatment with 10 ppm, bromine levels in the fat, liver, and muscle were ~11, 1.5, and 2.4 times higher, respectively, than levels of bromine in these tissues from controls. At 18 weeks after treatment with 1000 ppm, bromine levels in the fat, liver, and muscle were ~ 800, 9, 27 times higher than the control levels respectively.

In contrast with the high absorption rate for the hexabromobiphenyl congener, a commercial octabromobiphenyl mixture (45.2% octa, 47% nona, 5.7% deca, 1.8% hepta) appeared to be less well absorbed by rats after administration of a single dose of 1 mg/kg. Within the first 24 hours after dosing, 61.9% of the dose was found in the feces. This indicates that at least 38.1% of the dose was absorbed, but absorption may have been higher, since biliary excretion may have occurred. /Commercial mixture/

Increased bromide concentrations were observed in the liver and adipose tissue of rats exposed continuously to vapors of a commercial octabromobiphenyl mixture (33% octa, 60% nona, 6% deca, 1% hepta) (3.5 pg octabromobiphenyl/L air at equilibrium) for 15 weeks. Relative to controls, the concentration of bromide in liver and fat was increased by 39 and 100%, respectively; bromide concentration in skeletal muscle was not affected by treatment. /Commercial mixture/

For more Absorption, Distribution and Excretion (Complete) data for OCTABROMOBIPHENYL (6 total), please visit the HSDB record page.

Used in flame retardants; Commercial product was mixture of four or more polybrominated biphenyls; In two commercial products tested, nonabromobiphenyl was found in higher percentage than octabromobiphenyl; [HSDB]

Production discontinued in the US in 1979; [HSDB]

Ingredient in flame retardants. /Former use/

PBBs can be used as flame retardants and may be added to the plastics used to make products like computer monitors, televisions, textiles, and plastic foams to make them difficult to burn. However, the use of PBBs is banned or restricted in most areas due to their toxicity and persistence in the environment. (L628, L629)

Commercial octabromobiphenyl (Bromkal 80) contained at least four compounds. Assays of two commercial octabromobiphenyls showed the following compositions: 1.0-1.8% heptabromobiphenyl, 33.0-45.2% octabromobiphenyl, 47.4-60.0% nonabromobiphenyl, and 5.7-6.0% decabromobiphenyl. Notably, the major component of commercial octabromobiphenyl was nonabromobiphenyl, and not octabromobiphenyl.

1,1'-Biphenyl, ar,ar,ar,ar,ar',ar',ar',ar'-octabromo-: INACTIVE

Octabromobiphenyl was a minor ingredient in the flame retardant Firemaster BP-6 and Firemaster FF-1. Production of octabromobiphenyl was discontinued in 1979.