Calcium peroxide is a chemical compound, a solid molecule which, in the presence of water, releases hydrogen peroxide (hydrogen peroxide) over a wide pH range with a maximum of 0.47 g H2O2/g CaO2 . The decomposition process of calcium peroxide is rather slow and in humid air it decomposes at a temperature of about 620 K to form calcium hydroxide and oxygen.

It appears as a white or yellowish powder, soluble in water. It may also appear as a colourless liquid.

 What it is used for and where 

It is an oxidant used for the removal, disinfection and degradation of contaminants through the continuous release of hydrogen peroxide and is able to oxidise organic compounds that are more difficult for anaerobes to biodegrade (1). Oxygen source for soil remediation, water disinfection, fertilisers.

Pre-treatment on biohydrogen production.

Can be a potential substitute for hydrogen peroxide for tooth whitening (2).

Microbicidal agent (3).

In cosmetics, toothpastes it is used as a whitener, antimicrobial, deodorant.

In the paper industry it serves as a bleaching agent.

In the plastics industry it serves for cross-linking, curing and catalysis.

Safety

High doses of calcium peroxide can cause irritation and burning.

 Calcium peroxide studies

Appearance	White or yellowish powder. Liquid
Boiling Point	150.2ºC at 760 mmHg
Melting Point	>365°
Density	2.92
PSA	46.12000
Safety

• Molecular Formula    CaO₂
• Molecular Weight     72.08
• Exact Mass    71.952423
• CAS  1305-79-9    78403-22-2
• UNII    7FRO2ENO91
• EC Number   215-139-4
• DSSTox Substance ID  DTXSID4050489
• IUPAC  calcium;peroxide
• InChI=1S/Ca.O2/c;1-2/q+2;-2 
• InChl Key      LHJQIRIGXXHNLA-UHFFFAOYSA-N
• SMILES   [O-][O-].[Ca+2]
• MDL number  MFCD00015988
• PubChem Substance ID    24870335
• ChEBI    48233
• HS Code    2825909000  
• NACRES  NA:23   
• UN   1457

Synonyms

• Calcium dioxidanediide
• Calper G
• Calcium dioxide
• HSDB 965
• Calciumperoxid

References________________________________________________________________________

(1) Wang, J., & Li, Y. (2016). Synergistic pretreatment of waste activated sludge using CaO2 in combination with microwave irradiation to enhance methane production during anaerobic digestion. Applied Energy, 183, 1123-1132.

(2)  Bizhang M, Domin J, Danesh G, Zimmer S. Effectiveness of a new non-hydrogen peroxide bleaching agent after single use - a double-blind placebo-controlled short-term study. J Appl Oral Sci. 2017 Sep-Oct;25(5):575-584. doi: 10.1590/1678-7757-2016-0463. 

(3) Więckol-Ryk A, Thomas M, Białecka B. Improving the Properties of Degraded Soils from Industrial Areas by Using Livestock Waste with Calcium Peroxide as a Green Oxidizer. Materials (Basel). 2021 Jun 7;14(11):3132. doi: 10.3390/ma14113132.