Fire Anytime and Anywhere

Potassium chlorate (KClO3) itself doesn't create oxygen, but it contains oxygen atoms that can release oxygen gas when heated or decomposed.

When potassium chlorate is heated to a certain temperature, it decomposes into potassium chloride (KCl) and oxygen gas (O2):

2KClO3 → 2KCl + 3O2

The released oxygen gas is what supports the combustion of the match head and allows it to burn even in the presence of water. The oxygen from the decomposed potassium chlorate combines with other combustible materials in the match head to sustain the flame.