Potassium bromate

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Potassium bromate
Potassium bromate.png
Bromičnan draselný.JPG
Identifiers
CAS number 7758-01-2 YesY
PubChem 23673461
ChemSpider 22852 YesY
EC number 231-829-8
UN number 1484
KEGG C19295 N
ChEBI CHEBI:38211 YesY
RTECS number EF8725000
Jmol-3D images Image 1
Properties
Molecular formula KBrO3
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 (decomposes)
Solubility in water 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 slightly soluble in alcohol
insoluble in acetone, ethanol
Structure
Crystal structure hexagonal
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-342.5 kJ/mol
Hazards
MSDS ICSC 1115
EU Index 035-003-00-6
EU classification Carc. Cat. 2
Toxic (T)
Oxidant (O)
R-phrases R45 R9 R25
S-phrases S53 S45
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazard OX: Oxidizer. E.g., potassium perchlorateNFPA 704 four-colored diamond
Flash point Non-flammable
LD50 321 mg/kg
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.[1] 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).[2]

Potassium bromate has been banned from use in food products in the EU, Canada, Nigeria, Brazil,[3] South Korea, Peru and some other countries. It was banned in Sri Lanka in 2001[4] 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.[5]

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.[6]

References[edit]

  1. ^ Section 172.730 Potassium Bromate, Food Additives Permitted for Direct Addition to Food for Human Consumption, US Code of Federal Regulations, US Food and Drug Administration
  2. ^ IARC--Summaries & Evaluations: Potassium Bromate (Group 2B), International Agency for Research on Cancer
  3. ^ http://www.planalto.gov.br/ccivil_03/Leis/LEIS_2001/L10273.htm
  4. ^ Bridges Across Borders, Environmental Law Alliance Worldwide
  5. ^ California OEHHA Bromate Meets the Criteria for Listing
  6. ^ AsiaPulse News: Japan's Yamazaki Baking to use potassium bromate in bread