What does peroxide mean?
A peroxide is a chemical compound containing a distinctive bond between two oxygen atoms. This structure makes many peroxides reactive, and they may release reactive oxygen species or decompose into other compounds. The best-known member is hydrogen peroxide, whose aqueous solution is familiar as a antiseptic, bleaching agent, stain remover, and industrial chemical. Other peroxides occur in organic chemistry, where compounds containing peroxide bonds can be valuable intermediates but may also be hazardous because they can decompose explosively. The word is also used more loosely for hydrogen peroxide itself, especially in products marketed as “peroxide bleach.” In a verb construction, “to peroxide” means to treat a material with a peroxide or, in chemical processes, to convert it into a peroxide. Although the expression can sound familiar, its technical use is much less common than the everyday compound names involving the term.
A chemical compound containing a bonded pair of oxygen atoms, especially one capable of releasing reactive oxygen species.
"The peroxide decomposed rapidly when exposed to heat."
In everyday English, the term often means hydrogen peroxide specifically; in chemistry it names a broader class of compounds.
To treat a substance with a peroxide or cause it to undergo conversion into a peroxide.
"The fabric was peroxided before being rinsed in cold water."
This is a technical and relatively uncommon verb, especially outside industrial and laboratory contexts.
The plural is used when referring to a class of compounds or to several individual peroxide substances.
"Organic peroxides must be stored under carefully controlled conditions."
The familiar fizz of hydrogen peroxide comes from it breaking down into water and oxygen gas.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does peroxide come from?
The word entered English in the early 19th century from French peroxyde, formed by combining per- with oxyde. Its development followed the identification of compounds understood to contain more oxygen than the related oxides, and the name subsequently became a class term for compounds containing an oxygen–oxygen bond. The element oxide, and related words such as oxygen and oxidation, belong to the same broad chemical vocabulary rooted in the idea of oxygen-forming compounds.
Related word forms
How peroxide is actually used
In general use, “peroxide” most often refers to hydrogen peroxide. In technical chemistry, the term denotes the wider class of compounds containing an oxygen–oxygen bond. The verb is uncommon outside specialist and industrial contexts.
Easily confused with peroxide
An oxide broadly denotes a compound of oxygen with another element, whereas a peroxide specifically contains a bonded pair of oxygen atoms.