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[1][2]. The presence of it in Coca Cola's Dasani forced a recall
of that product in the UK.[3] 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.




