Calcium peroxide or calcium dioxide is the inorganic compound with the formula CaO2. It is the peroxide (O22−) salt of Ca2+. Commercial samples can be yellowish, but the pure compound is white. It is almost insoluble in water.
3D model (JSmol)
|E number||E930 (glazing agents, ...)|
CompTox Dashboard (EPA)
|Molar mass||72.0768 g/mol|
|Appearance||white or yellowish powder|
|Melting point||~ 355 °C (671 °F; 628 K) (decomposes)|
Refractive index (nD)
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|>5000 mg/kg (oral, rat) |
>10000 mg/kg (dermal, rat)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Structure and stability
- Ca(OH)2 + H2O2 → CaO2 + 2 H2O
It is mainly used as an oxidant to enhance the extraction of precious metals from their ores. In its second main application, it is used as a food additive under the E number E930 it is used as flour bleaching agent and improving agent.
In agriculture it is used in the presowing treatments of rice seed. Also, calcium peroxide has found use in the aquaculture to oxygenate and disinfect water. In the ecological restoration industry it is used in the treatment of soils. Calcium peroxide is used in a similar manner to magnesium peroxide for environmental restoration programs. It is used to restore soil and groundwater contaminated with petroleum by the process of enhanced in-situ bioremediation.
- Zhao, X.; Nguyen, M.C.; Wang, C.Z.; Ho, K.M. (2013). "Structures and stabilities of alkaline earth metal peroxides XO2 (X = Ca, Be, Mg) studied by a genetic algorithm" (PDF). RSC Advances. doi:10.1039/C3RA43617A.
- Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort. "Peroxo Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_177.pub2.CS1 maint: multiple names: authors list (link)