Potassium bromate

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Potassium bromate
Potassium bromate.png
Bromičnan draselný.JPG
Identifiers
CAS number7758-01-2 YesY
PubChem23673461
ChemSpider22852 YesY
EC number231-829-8
UN number1484
KEGGC19295 N
ChEBICHEBI:38211 YesY
RTECS numberEF8725000
Jmol-3D imagesImage 1
Properties
Molecular formulaKBrO3
Molar mass167.00 g/mol
Appearancewhite crystalline powder
Density3.27 g/cm3
Melting point350 °C (662 °F; 623 K)
Boiling point370 °C (698 °F; 643 K) (decomposes)
Solubility in water3.1 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)
Solubilityslightly soluble in alcohol
insoluble in acetone, ethanol
Structure
Crystal structurehexagonal
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-342.5 kJ/mol
Hazards
MSDSICSC 1115
EU Index035-003-00-6
EU classificationCarc. Cat. 2
Toxic (T)
Oxidant (O)
R-phrasesR45 R9 R25
S-phrasesS53 S45
NFPA 704
Flash pointNon-flammable
LD50157 mg/kg (oral, rat)[1]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references
 
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Potassium bromate
Potassium bromate.png
Bromičnan draselný.JPG
Identifiers
CAS number7758-01-2 YesY
PubChem23673461
ChemSpider22852 YesY
EC number231-829-8
UN number1484
KEGGC19295 N
ChEBICHEBI:38211 YesY
RTECS numberEF8725000
Jmol-3D imagesImage 1
Properties
Molecular formulaKBrO3
Molar mass167.00 g/mol
Appearancewhite crystalline powder
Density3.27 g/cm3
Melting point350 °C (662 °F; 623 K)
Boiling point370 °C (698 °F; 643 K) (decomposes)
Solubility in water3.1 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)
Solubilityslightly soluble in alcohol
insoluble in acetone, ethanol
Structure
Crystal structurehexagonal
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-342.5 kJ/mol
Hazards
MSDSICSC 1115
EU Index035-003-00-6
EU classificationCarc. Cat. 2
Toxic (T)
Oxidant (O)
R-phrasesR45 R9 R25
S-phrasesS53 S45
NFPA 704
Flash pointNon-flammable
LD50157 mg/kg (oral, rat)[1]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Potassium bromate (KBrO3), is a bromate of potassium and takes the form of white crystals or powder.

Preparation[edit]

Potassium bromate is produced by passing bromine into a solution of potassium hydroxide. An industrial electrolytic process is used for large scale production.

Alternatively, it can be created as a by-product of potassium bromide production by absorption of bromine from ocean water into potassium carbonate.

Uses in baking[edit]

Although banned for use in foods by many countries, in the USA Potassium bromate is typically used as a flour improver (E number E924). It acts to strengthen the dough and to allow higher rising. It is an oxidizing agent, and under the right conditions, will be completely used up in the baking bread. However, if too much is added, or if the bread is not baked long enough or not at a high enough temperature, then a residual amount will remain, which may be harmful if consumed[citation needed]. Potassium bromate might also be used in the production of malt barley where the U.S. Food and Drug Administration (FDA) has prescribed certain conditions where it may be used safely, which includes labeling standards for the finished malt barley product.[2] It is a very powerful oxidizer (E° = 1.5 volts comparable to potassium permanganate).

Regulation[edit]

Potassium bromate is classified as a category 2B carcinogen (possibly carcinogenic to humans) by the International Agency for Research on Cancer (IARC).[3]

Potassium bromate has been banned from use in food products in the EU, Canada, Nigeria, Brazil,[4] South Korea, Peru and some other countries. It was banned in Sri Lanka in 2001[5] and China in 2005.

In the United States of America, it has not been banned. The FDA sanctioned the use of bromate before the Delaney clause of the Food, Drug, and Cosmetic Act—which bans potentially carcinogenic substances— went into effect in 1958. But since 1991 the FDA has urged bakers to voluntarily stop using it. In California a warning label is required when bromated flour is used.[6]

Japanese baked goods manufacturers stopped using potassium bromate voluntarily in 1980; however, Yamazaki Baking resumed its use in 2005, claiming they had new production methods to reduce the amount of the chemical which remained in the final product.[7]

References[edit]