The bromate anion, BrO3-, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, (NaBrO3), and potassium bromate, (KBrO3).
Bromates are formed when ozone and bromide ion react according to the following abbreviated reaction:
Br- + O3 ? BrO3
Bromate is also formed in electrochemical processes, such as formation of hypochlorite ion used in municipal water processes, when bromide ion is present. Additionally bromate ion is produced when chlorine dioxide is used in water, the bromide ion is present, and the water is exposed to sunlight.
This reaction occurs in water systems where bromide is dissolved in water and ozone is used to disinfect the water, especially under high pressures. This reaction is undesirable because bromate is a suspected carcinogen. The presence of it in Coca Cola's Dasani forced a recall of that product in the UK. Proposals to reduce bromate formation include switching to atmospheric tank contact systems, lowering the water pH to between 5.9 - 6.3, and limiting the doses of ozone.
Keep in a tightly closed container, stored in a cool, dry, ventilated area. Protect against physical damage. Isolate from acids and alkalis. Containers of this material may be hazardous when empty since they retain product residues (dust, solids); observe all warnings and precautions listed for the product.
It is typically used as a flour improver (E number E924), strengthening the dough and allowing 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 cooked long enough or not at a high enough temperature, then a residual amount will remain, which may be harmful if consumed. Potassium bromate might also be used in the production of malt barley where the United States FDA has prescribed certain conditions where it may be used safely, which includes labeling standards for the finished malt barley product. It is a very powerful oxidizer (E° = 1.5 volts comparable to potassium permanganate). Bromate is considered a category 2B (possibly carcinogenic to humans) carcinogen by the International Agency for Research on Cancer (IARC).
Potassium bromate has been banned from use in food products in Europe, as well as the United Kingdom in 1990, and Canada in 1994, and most other countries. It was banned in Sri Lanka in 2001 and China in 2005. It is also banned in Nigeria and Brazil.
In the United States it has not been banned. The FDA sanctioned the use of bromate before the Delaney clause of the Food, Drug, and Cosmetic Act went into effect in 1958 - which bans carcinogenic substances - so that it is more difficult for it to now be banned. Instead, since 1991 the FDA has urged bakers to voluntarily stop using it. In California a warning label is required when bromated flour is used.
An aqueous solution of Iron sulphate is claimed to be effective at removing moss from roofs. Spraying a mixture on moss will allow the wind to simply blow off the remaining debris, however it is not recommended for use on lawns as it is as effective at removing grass.