Potassium bromate
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| Names | |||
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| IUPAC name
Potassium bromate
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Other names
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| Identifiers | |||
3D model (JSmol)
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| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.028.936 | ||
| EC Number |
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| 15380 | |||
| KEGG | |||
PubChemCID
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| RTECS number |
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| UNII | |||
| UN number | 1484 | ||
CompTox Dashboard(EPA)
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| Properties | |||
| KBrO 3 | |||
| Molar mass | 167.00 g/mol | ||
| Appearance | white crystalline powder | ||
| Density | 3.27 g/cm³ | ||
| Melting point | 350 °C (662 °F; 623 K) | ||
| Boiling point | 370 °C (698 °F; 643 K) (decomposes) | ||
| 3.1 g/100 mL (0 °C) 6.91 g/100 mL (20 °C) 13.3 g/100 mL (40 °C) 49.7 g/100 mL (100 °C) | |||
| Solubility | Insoluble inacetone | ||
| −52.6·10−6cm³/mol | |||
| Structure | |||
| hexagonal | |||
| Thermochemistry | |||
Std enthalpy of
formation(ΔfH⦵298) |
−342.5 kJ/mol | ||
| Hazards | |||
| GHSlabelling: | |||
  
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| Danger | |||
| H271,H301,H350 | |||
| P201,P202,P210,P220,P221,P264,P270,P280,P281,P283,P301+P310,P306+P360,P308+P313,P321,P330,P370+P378,P371+P380+P375,P405,P501 | |||
| NFPA 704(fire diamond) | |||
| Flash point | Non-flammable | ||
| Lethal doseor concentration (LD, LC): | |||
LD50(median dose)
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157 mg/kg (oral, rat)[1] | ||
| Safety data sheet(SDS) | "ICSC 1115". | ||
| Related compounds | |||
Otheranions
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Potassium chlorate Potassium iodate | ||
Othercations
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Sodium bromate Calcium bromate | ||
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa).
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Potassium bromate(KBrO
3) is abromateofpotassiumand takes the form of white crystals or powder. It is a strong oxidizing agent.
Preparation
[edit]Potassium bromate is produced whenbromineis passed through a hot solution ofpotassium hydroxide.This first forms unstablepotassium hypobromite,which quicklydisproportionatesinto bromide and bromate:[2]
- 3BrO−
2Br−
+BrO−
3
Electrolysis ofpotassium bromidesolutions will also give bromate. Both processes are analogous to those used in the production ofchlorates.[citation needed]
Potassium bromate is readily separated from the potassium bromide present in both methods owing to its much lower solubility; when a solution containing potassium bromate and bromide is cooled to 0°C, nearly all bromate will precipitate, while nearly all of the bromide will stay in solution.[2]
Uses in baking
[edit]Potassium bromate is typically used in the United States as aflourimprover (E numberE924). It acts to strengthen thedoughand to allow higher rising. It is anoxidizing agent,and under the right conditions, is reduced tobromidein the baking process.[3][4]However, if too much is added, or if the bread is under-baked long or baked at a low enough temperature, then a residual amount remains, which may be harmful if consumed.[4]
Potassium bromate may be used in the production ofmaltbarley, but under safety conditions prescribed by theU.S. Food and Drug Administration(FDA), including labeling standards for the finished product.[5]It is a powerful oxidizer (electrode potential= 1.5volts,similar topotassium permanganate).[citation needed]
Regulation
[edit]Potassium bromate is classified as a category 2Bcarcinogenby theIARC.[6]The FDA allowed the use of bromate before theDelaney clauseof theFood, Drug, and Cosmetic Act– which bans potentially carcinogenic substances – went into effect in 1958. Since 1991, the FDA has urged bakers to not use it, but has not mandated a ban.
Japanese baked goods manufacturers stopped using potassium bromate voluntarily in 1980; however,Yamazaki Bakingresumed its use in 2005, claiming it had new production methods to reduce the amount of the chemical which remained in the final product.[7]
Potassium bromate is banned from food products in the European Union, Argentina, Brazil,[8]Canada, Nigeria, South Korea, and Peru. It was banned in Sri Lanka in 2001,[9]China in 2005,[10]and India in 2016,[11]but it is allowed in most of the United States. As of May 2023, the U.S. state ofNew Yorkis considering banning the use of potassium bromate.[12]
InCalifornia,a warning label is required when bromated flour is used.[13]In October 2023,Californiaenacted a law that banned the manufacture, sale, and distribution of potassium bromate (along with three other additives:brominated vegetable oil,propylparaben,andRed 3). The law takes effect in 2027. It was the first U.S. state to ban it.[14][15][16]
References
[edit]- ^"Potassium bromate".chem.sis.nlm.nih.gov.ChemIDplus. U.S.National Institutes of Health.RN7758-01-2.
- ^abSynthesis, separation, and purification ofKBrandKBrO(PDF).Pre-Labs (course notes). Advanced Placement Chemistry.Harvard-Westlake School.Archived fromthe original(PDF)on 16 May 2017.Retrieved14 September2016– via Harvard-Westlake School (hwscience ).
- ^"Volume 13, Series 6, page 3136".Federal Register(compendium). Office of the Federal Register, National Archives and Records Service. Washington, DC: General Services Administration. 1948 – via Google Books.
- ^abKurokawa, Y.; Maekawa, A.; Takahashi, M.; Hayashi, Y. (1 July 1990)."Toxicity and carcinogenicity of potassium bromate – a new renal carcinogen".Environmental Health Perspectives.87:309–335.doi:10.1289/ehp.9087309.ISSN0091-6765.PMC1567851.PMID2269236.
- ^"Potassium Bromate".Food Additives Permitted for Direct Addition to Food for Human Consumption (laws & regulations). U.S. Code of Federal Regulations.U.S. Food and Drug Administration.section 172.730 – via ecfr.gov.
- ^ Potassium bromate (group 2B)(Report). IARC Summaries & Evaluations. Vol. 73.International Agency for Research on Cancer(IARC). 73-17 – via inchem.org.
- ^
Kawo, Kuro; et al. (c. 1990). "Japan's Yamazaki Baking to use potassium bromate in bread". AsiaPulse News.Cited by
Duvvuri, Shreemathi; Panchagnula, Shobharani (September–October 2016)."Analysis of potassium iodate and potassium bromate in bakery products by electro-analytical techniques"(PDF).International Journal of Trend in Research and Development.3(5): 412–413.ISSN2394-9333– via ijtrd. - ^ "Dispõe sobre o uso do bromato de potássio na farinha e nos produtos de panificação"[Regarding the use of potassium bromate in flour and bakery products] (in Portuguese). c. 2001 – via planalto.gov.br.
- ^"[title not cited]".E‑Law Advocate.No. 4. Bridges Across Borders. (2001). Archived fromthe originalon 2018-05-16.Retrieved2006-10-10.
Environmental Law Alliance Worldwide
[citation not found] - ^ "Importer halts unsafe potato chips from the U.S."China Daily.7 December 2007.Retrieved2023-02-21– via chinadaily.cn.
- ^ "India bans use of cancer-causing additive, potassium bromate, in bread, other food".The Times of India.21 June 2016 [20 June 2016].Retrieved20 June2016– via timesofindia.indiatimes.
- ^ Smith, Dana G. (13 April 2023)."Two states have proposed bans on common food additives linked to health concerns".The New York Times.Retrieved23 May2023– via nytimes.
- ^ "Bromate meets the criteria for listing".CRNR notices.oehha.ca.gov.Proposition 65.California Office of Environmental Health Hazard Assessment.Archived fromthe originalon 2013-12-03.
- ^Cimons, Marlene (2023-10-11)."California isn't banning Skittles, but four additives will be removed".Washington Post.Retrieved2024-08-18.
- ^"AB-418 The California Food Safety Act".ca.gov.
- ^ "California becomes first U.S. state to ban 4 potentially harmful chemicals in food".CNN.10 October 2023.