Hydrogen peroxide is used as a topical antiseptic in dilute
solutions, and as a water purifier in stronger solutions.
It is also famous as a hair bleach.
Hydrogen peroxide breaks down into water and oxygen. An liter
of 3% hydrogen peroxide will generate 10 liters of oxygen when
a catalyst is used to facilitate the breakdown. Catalysts can
be metals such as iron, copper, or silver, or organics
such as the enzyme catalase found in blood (it contains a heme
group, like hemoglobin does, and the iron catalyzes the reaction).
Catalase is an important enzyme in cells because hydrogen
peroxide is a byproduct of metabolism, and can poison the
cell unless it is decomposed quickly. Hydrogen peroxide is
also produced by cells in the immune system, and catalase removes
The 3% hydrogen peroxide you get at the drugstore is often
protected from decomposing by the addition of
or tin compounds. These stabilizers lock up the iron, copper, and
other transition metals that can act as catalysts.
hydrogen peroxide: InChI=1/H2O2/c1-2/h1-2H