Tribromessigsure

Chlorination of drinking water generates disinfection by-products (DBPs) , which have been shown to disrupt spermatogenesis in rodents at high doses, suggesting that DBPs could pose a reproductive risk to men. ... A cohort study /was conducted/ to evaluate semen quality in men with well-characterized exposures to DBPs. ... The results of the present study do not support an association between exposure to DBPs at levels approaching regulatory limits and adverse sperm outcomes, although /there was/ an association between total organohalides and sperm concentration. ... The lone association of total organohalide exposure with sperm concentration may lend support to findings that have suggested that total organohalide is a stronger risk factor for adverse pregnancy outcomes than any of the regulated DBP groups or species and that the toxicity of total organohalides is greater than that of the individual or subclasses of DBPs. ... /Disinfection by-products/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 5.3(SRC), determined from a water solubility of 2.0X10+5 mg/L(2) and a regression-derived equation(3), indicates that tribromoacetic acid is expected to have very high mobility in soil(SRC). The pKa of tribromoacetic acid is 0.72(4), indicating that this compound will primarily exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Tribromoacetic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.8X10-4 mm Hg(SRC), determined from a fragment constant method(6). Limited data are available regarding the biodegradation of tribromoacetic acid in soil. However, tribromoacetic acid (0.1% w/v) was used as a carbon source by Pseudomonas and Nocardia when measured for halide released over a period of 20 days at 30 °C(7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 5.3(SRC), determined from a water solubility of 2.0X10+5 mg/L(2) and a regression-derived equation(3), indicates that tribromoacetic acid is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 0.72(4) indicates tribromoacetic acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(5). According to a classification scheme(6), an estimated BCF of 0.63(SRC), from its water solubility(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Limited data are available regarding the biodegradation of tribromoacetic acid in water. However, tribromoacetic acid (0.1% w/v) was used as a carbon source by Pseudomonas and Nocardia when measured for halide released over a period of 20 days at 30 °C(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tribromoacetic acid, which has an estimated vapor pressure of 2.8X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase tribromoacetic acid is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 30.9 days(SRC), calculated from its rate constant of 5.2X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Tribromoacetic acid does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=75-96-7][Available from: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=75-96-7]

The Koc of tribromoacetic acid is estimated as 5.3(SRC), using a water solubility of 2.0X10+5 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that tribromoacetic acid is expected to have very high mobility in soil. The pKa of tribromoacetic acid is 0.72(4), indicating that this compound will primarily exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5).

/SIGNS AND SYMPTOMS/ Corrosive.

/SIGNS AND SYMPTOMS/ ... Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. Inhalation may result in spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis, and pulmonary edema. Material is extremely destructive to tissue of the mucous membranes and upper respiratory tract, eyes, and skin.

/EPIDEMIOLOGY STUDIES/ Chlorination of drinking water generates disinfection by-products (DBPs) , which have been shown to disrupt spermatogenesis in rodents at high doses, suggesting that DBPs could pose a reproductive risk to men. ...This study ...assessed DBP exposure and testicular toxicity, as evidenced by altered semen quality. ... A cohort study /was conducted/ to evaluate semen quality in men with well-characterized exposures to DBPs. Participants were 228 presumed fertile men with different DBP profiles. They completed a telephone interview about demographics, health history, water consumption, and other exposures and provided a semen sample. Semen outcomes included sperm concentration and morphology, as well as DNA integrity and chromatin maturity. Exposures to DBPs were evaluated by incorporating data on water consumption and bathing and showering with concentrations measured in tap water. ... Multivariable linear regression /was used/ to assess the relationship between exposure to DBPs and adverse sperm outcomes. ... The mean (median) sperm concentration and sperm count were 114.2 (90.5) million/mL and 362 (265) million, respectively. The mean (median) of the four trihalomethane species (THM4) exposure was 45.7 (65.3) ug/L, and the mean (median) of the nine haloacetic acid species (HAA9) exposure was 30.7 (44.2) ug/L. These sperm parameters were not associated with exposure to these classes of DBPs. For other sperm outcomes, we found no consistent pattern of increased abnormal semen quality with elevated exposure to trihalomethanes (THMs) or haloacetic acids (HAAs) . The use of alternate methods for assessing exposure to DBPs and site-specific analyses did not change these results. ... Overall, the results of the present study do not support an association between exposure to DBPs at levels approaching regulatory limits and adverse sperm outcomes, although /there was/ an association between total organohalides and sperm concentration that was in line with /the/ hypothesis.... The lone association of total organohalide exposure with sperm concentration may lend support to findings that have suggested that total organohalide is a stronger risk factor for adverse pregnancy outcomes than any of the regulated DBP groups or species ... and that the toxicity of total organohalides is greater than that of the individual or subclasses of DBPs. ... Previous studies have suggested that exposures to THMs via bathing and showering may be more strongly associated with adverse reproductive outcomes than other exposure indicators... /These/ results did not support these findings. /Disinfection by-products/

Tribromoacetic acid's formation as a chemical byproduct of chlorination and chloramination of drinking water(1), and its use as a brominating agent and catalyst for polymerization(2) may result in its release to the environment through various waste streams.

An estimated BCF of 0.63 was calculated for tribromoacetic acid(SRC), using a water solubility of 2.0X10+5 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

A pKa of 0.72(1) indicates tribromoacetic acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(2). Tribromoacetic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.8X10-4 mm Hg(SRC), determined from a fragment constant method(3).

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/The potential toxicity of tribromoacetic acid (TBD) was evaluated using a short-term reproductive and developmental toxicity screen. This study design was selected to identify the process (development; female /rat/ reproduction; male /rat/ reproduction; various somatic organs/processes) that is the most sensitive to tribromoacetic acid exposure. ... The results of this study indicate that TBA at up to 400 ppm marginally reduced water consumption and did not affect reproductive function or produce general toxicity. From these data, TBA is not a reproductive toxicant in males or females at doses up to 400 ppm. This conclusion rests heavily on the shortness of the current exposure, and should be replicated using a longer study before the data are relied on.

/GENOTOXICITY/ /Investigators/ examined the genotoxicity of Bromoacetic acid (MBA), dibromoacetic acid (DBA), and tribromoacetic acid (TBA) in the SOS chromotest in Escherichia coli PQ37, the Ames fluctuation assay utilizing Salmonella typhimurium strain TA100 and the newt micronucleus assay in larvae at stage 53 of the developmental table. MBA was negative in the SOS chromotest at levels as high as 1000 ug/mL and in the newt micronucleus assay. However, it was active at concentrations as low as 20 ug/mL in the Ames fluctuation assay with S9 fraction added to the incubation medium. DBA was positive with and without S9 fraction in the SOS chromotest, requiring 100 ug/mL in the former case and 200 ug/mL in the latter. Thus, it is about 5 times as potent as DCA in this test. In the Ames fluctuation assay, DBA was active at 10 ug/mL without S9 and at 30 ug/mL with S9. TBA was active in the SOS chromotest at 100 ug/mL with S9 but required 2000 ug/mL for activity in the Ames fluctuation assay without S9.

/GENOTOXICITY/ Cytotoxicity and genotoxicity assays were used to analyze drinking water disinfection by-products (DBPs) in Chinese hamster ovary (CHO) AS52 cells. ... Data were also available to compare these results with cytotoxicity and mutagenicity studies in Salmonella typhimurium. The rank order in decreasing chronic cytotoxicity measured in a microplate-based assay was bromoacetic acid (BA) >> 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) > dibromoacetic acid (DBA) > chloroacetic acid (CA) > KBrO(3) > tribromoacetic acid (TBA) > EMS (ethylmethanesulfonate, positive control) > dichloroacetic acid (DCA) > trichloroacetic acid (TCA). The induction of DNA strand breaks by these agents was measured by alkaline single-cell gel electrophoresis (SCGE, comet assay) and the rank order in decreasing genotoxicity was BA >> MX > CA > DBA > TBA > EMS > KBrO(3), while DCA and TCA were refractory. BA was more cytotoxic (31x) and genotoxic (14x) than MX in CHO cells. BA was over 400x more genotoxic than potassium bromate. The brominated haloacetic acids (HAAs) were more cytotoxic and genotoxic than their chlorinated analogs. The HAAs expressed a statistically significant inverse relationship in CHO cell cytotoxicity and genotoxicity as a function of increased numbers of halogen atoms per molecule. A quantitative comparison was conducted with results from a previous study with cytotoxicity and mutagenicity in S. typhimurium. There was no correlation between chronic CHO cell and bacterial cell cytotoxicity. DBP-induced CHO cell cytotoxicity was not related to mutagenic potency in S. typhimurium. Cytotoxicity in CHO cells was statistically significant and highly correlated to CHO cell genotoxicity. Finally, ... the DBP genotoxic potency in CHO cells and the mutagenic potency in S. typhimurium were not related. This suggests that toxicity data in S. typhimurium did not quantitatively predict the toxic effects of DBPs in mammalian cell systems.

The rate constant for the vapor-phase reaction of tribromoacetic acid with photochemically-produced hydroxyl radicals has been estimated as 5.2X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 30.9 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tribromoacetic acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Tribromoacetic acid does not contain chromophores that absorb at wavelengths >290 nm(3) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).