What Is the Difference Between Oxidizers and Disinfectants?

The terms oxidizer and disinfectant are often confused and used inaccurately. Here is the difference between oxidizers and disinfectants. This is useful information when considering the control of Legionella and other opportunistic waterborne pathogens.

In simple terms, an oxidizer can be a type of disinfectant, but not every disinfectant is an oxidizer. Oxidizing disinfectants work by oxidizing microorganisms, while nonoxidizing disinfectants control microorganisms through other mechanisms.

What Is an Oxidizer?

An oxidizer is a substance that has the ability to accept electrons or oxidize other substances. Strong oxidizers can oxidize the cell membrane of microorganisms, which results in a loss of structure and leads to cell lysis and often death. In doing so, they are disinfecting.

What Is a Disinfectant?

Disinfectants kill germs such as certain bacteria, viruses, mildews, or fungi and are regulated by the EPA. They kill microbes by destroying their cell walls or interfering with their metabolism.

What Types of Disinfectants Are Used?

Disinfectants can be split into two broad groups: oxidizing disinfectants and nonoxidizing disinfectants.

Oxidizing disinfectants include the halogens, chlorine, iodine, bromine, and chlorine dioxide, as well as oxygen-releasing materials such as peracetic acid and hydrogen peroxide. Nonoxidizing disinfectants include quaternary ammonium compounds, amphoterics, biguanides, and acid anionics.

For more information about chemical-based disinfectants used for Legionella control, see our page about controlling Legionella with chemical-based disinfectants.

How Are Oxidizers and Disinfectants Related?

Strong oxidizers are a type of disinfectant. In fact, oxidizing disinfectants, including chlorine, chloramines, and ozone, are the final barrier in the Environmental Protection Agency-recommended multibarrier approach to providing pathogen-free water to the consumer.

Not every disinfectant is an oxidizer, but all strong oxidizers are disinfectants.

Why Does This Difference Matter for Legionella Control?

Understanding the difference between oxidizers and disinfectants is useful when considering the control of Legionella and other opportunistic waterborne pathogens. The appropriate approach depends on the facility, water system, and overall treatment strategy.

Learn more about water management plans and secondary disinfection for Legionella and other waterborne pathogens.

Learn more about the best approaches for controlling Legionella and other pathogens by contacting Legionella Control Systems.