Oxidizer (noun)

A substance that causes or promotes oxidation.

Origin:

From oxidize + -er.

Examples:

1. Oxygen is a common oxidizer in combustion reactions.
2. Potassium nitrate is often used as an oxidizer in fireworks.
3. The oxidizer in rocket fuel helps the fuel to burn.
4. Some metals rust because of the presence of an oxidizer in the air.
5. The oxidizer in the pool chemical helped to keep the water clean.