Environmental Abiotic Degradation:
The rate constant for the vapor-phase reaction of bromine with photochemically-produced hydroxyl radicals has been measured as 4.5X10-11 cu cm/molecule-sec at 25 deg C(1). This corresponds to an atmospheric half-life of about 8.6 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). The reaction of bromine with photochemically-produced hydroxyl radicals yields the bromide radical and HOBr(1). In the presence of moisture and sunlight, bromine has a short life-time and is transformed into hydrobromic acid and oxygen(3). In water below pH 3, bromine is present almost entirely as the molecular Br2(3); above pH 3, the fraction present as Br2 decreases and HOBr is formed(3); between pH 6 and pH 8, most of the bromine is present as HOBr(3). Bromine gas absorbs at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).
[(1) NIST; NIST Chemistry WebBook. Bromine (7726-95-6). NIST Standard Reference Database No. 69, June 2013 Release. Washington, DC: US Sec Commerce. Available from, as of Oct 14, 2014: http://webbook.nist.gov (2) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Oct 14, 2014: http://www.epa.gov/oppt/exposure/pubs/episuitedl.htm (3) European Commission; IUCLID Dataset, Bromine (CAS No. 7726-95-6), Feb 19, 2000. Available from, as Oct 14, 2014: http://esis.jrc.ec.europa.eu/doc/IUCLID/datasheet/7726956.pdf (4) Passchier AA et al; J Phys Chem 71: 937-942 (1967)] **PEER REVIEWED**
Volatilization from Water/Soil:
The Henry's Law constant for bromine is 1.32X10-3 atm-cu m/mole(1). This Henry's Law constant indicates that bromine is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 4.5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 5 days(SRC). Bromine's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Bromine is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 212 mm Hg at 25 deg C(3). Bromine is reported to vaporize rapidly at room temperature(4).
[(1) Sander R; Compilation of Henry's Law Constants for Inorganic and Organic Species of Potential Importance in Environmental Chemistry. Available from, as of Oct 10, 2014: http://www.henrys-law.org/henry.pdf (2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc pp. 15-1 to 15-29 (1990) (3) Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, DC: Taylor and Francis (1989) (4) O'Neil MJ, ed; The Merck Index. 15th ed., Cambridge, UK: Royal Society of Chemistry, p. 246 (2013)] **PEER REVIEWED**
Environmental Standards & Regulations:
FIFRA Requirements:
The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with the following conditions: (1) The food additives are present as a result of treating water aboard ships with a polybrominated ion-exchange resin (as a source of bromine) under the supervision of trained personnel. (2) Residual bromine levels are controlled to not exceed 1.0 part per million (ppm) in the final treated water. Control is effected using calibrated recirculating or proportioning bromine feeder equipment and periodic checks of residual bromine using a bromine test kit. To assure safe use of the additives, the label and labeling of the disinfectant formulation containing the food additives shall conform to the label and labeling registered by the U.S. Environmental Protection Agency. (3) No tolerance is established for bromide ion levels. /Bromide ion and residual bromine/
[40 CFR 180.519 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 27, 2014: http://www.ecfr.gov **PEER REVIEWED**
A tolerance exemption for use of residual bromine in potable water has been granted. In the 1993 Bromine RED, the Agency indicated the need for confirmatory data (i.e., 171-4(f) magnitude of residue in potable water) to alleviate potential concerns about the conversion of bromine into bromate, which is a known carcinogen. In response to the data call-in, two studies were conducted to determine the magnitude of bromate residues in potable water. At the pH level expected for drinking water disinfection on ships/oil platforms, the bromate levels in these studies were non detect. Hence at this time the Agency does not have concerns for the use of bromine as a drinking water disinfectant (on ships/oil platforms). The Agency has evaluated all current registered uses of bromine and has determined based on available data, that there is a reasonable certainty that no harm to any population subgroup will result from exposure to bromine. Therefore, no mitigation measures are needed, and the current tolerances established at 40 CFR180.519 for residues of residual bromine in potable water are now considered reassessed under section 408(q) of the FFDCA.
[USEPA/Office of Prevention, Pesticides and Toxic Substances; Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk Management Decision (TRED) for Bromine p.2 (September 2005). Available from, as of November 3, 2014: http://www.epa.gov/pesticides/reregistration/status.htm **PEER REVIEWED**
Based on the reviews of the generic data for the active ingredient bromine, the Agency has sufficient information on the health effects of bromine and on its potential for causing adverse effects to the environment. The Agency has determined that bromine products, labled and used as specified in this Reregistration Eligibility Decision, will not pose unreasonable risks or adverse effects to humans or the environment, and therefore, the Agency concludes that products containing bromine for all uses are eligible for reregistration.
[USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document for Bromine p.15 (December 1993). Available from, as of November 3, 2014: http://www.epa.gov/pesticides/reregistration/status.htm **PEER REVIEWED**
As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Bromine is found on List D. Case No: 4015; Pesticide type: Insecticide, fungicide, antimicrobial; Case Status: RED Approved 01/94; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Bromine; Data Call-in (DCI) Date(s): 11/15/93; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.
[United States Environmental Protection Agency/ Prevention, Pesticides and Toxic Substances; Status of Pesticides in Registration, Reregistration, and Special Review. (1998) EPA 738-R-98-002, p. 298] **PEER REVIEWED**