Oxidizing Agent Definition and Examples

This is the hazard symbol for oxidizing agents.
This is the hazard symbol for oxidizing agents.

European Chemicals Bureau/Public domain

by Anne Marie Helmenstine, Ph.D.
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
Updated May 08, 2019

An oxidizing agent is a reactant that removes electrons from other reactants during a redox reaction. The oxidizing agent typically takes these electrons for itself, thus gaining electrons and being reduced. An oxidizing agent is thus an electron acceptor. An oxidizing agent may also be viewed as a species capable of transferring electronegative atoms (especially oxygen) to a substrate.

Oxidizing agents are also known as oxidants or oxidizers.

Examples of Oxidizing Agents

Hydrogen peroxide, ozone, oxygen, potassium nitrate, and nitric acid are all oxidizing agents. All of the halogens are oxidizing agents (e.g., chlorine, bromine, fluorine).

Oxidizing Agent Versus Reducing Agent

While an oxidizing agent gains electrons and is reduced in a chemical reaction, a reducing agent loses electrons and is oxidized during a chemical reaction.

Oxidizer as a Dangerous Material

Because an oxidizer may contribute to combustion, it may be classified as a dangerous material. The hazard symbol for an oxidizer is a circle with flames on top of it.