CALCIUM PEROXIDE (CAO2): PROPERTIES, RISKS AND USES - CHEMISTRY - 2024

The calcium peroxide, also known as calcium dioxide, is a chemical compound of formula CaO ₂. It occurs with the interaction of the dissolution of a salt or calcium hydroxide and sodium peroxide with subsequent crystallization.

Calcium peroxide is produced by precipitation of the octahydrate compound from an aqueous solution, followed by dehydration at temperatures above 100 ° C.

Figure 1: Structure of calcium peroxide.

Calcium peroxide breaks down to release oxygen when in contact with hydrated material. CaO ₂ is one of the most temperature stable inorganic peroxides and decomposes slowly in humid air.

A 1: 100 aqueous suspension has a pH of about 12. Except for its stable oxygen-releasing capacity, CaO ₂ has similar functions to other peroxides: bleaching, disinfection, and deodorization. In addition, it is noteworthy to note that CaO ₂ is respectful with the environment due to its properties. (Kingsfield Inc, 2011).

Physical and chemical properties of calcium peroxide

Calcium peroxide is a white or yellowish powder with no characteristic aroma or taste (National Center for Biotechnology Information., 2017).

Figure 2: appearance of calcium peroxide.

CaO ₂ has a molecular weight of 72.0768 g / mol and a density of 2.91 g / ml. The compound has a melting point of 200 ° C and decomposes above 355 ° C. It is slightly soluble in water, forming hydrogen peroxide. It has a pKa of 12.5 (Royal Society of Chemistry, 2015).

Calcium Peroxide is an explosion hazard if mixed with finely divided organic matter. The compound is not combustible in itself, but rather accelerates the combustion of combustible material. This is because mixtures of combustible material and peroxide can ignite from friction or contact with moisture.

Reactivity and hazards

Calcium peroxide, even though it is a relatively stable compound compared to other peroxides, is classified as an explosive compound and a strong oxidizing agent.

Contact with calcium peroxide can be severely irritating and can burn the skin and eyes. Exposure can irritate the eyes, nose, and throat.

Long-term exposure can damage the skin. Higher levels of calcium peroxide can irritate the lungs and cause coughing or shortness of breath.

Even higher exposures can cause fluid to build up in the lungs (pulmonary edema), leading to death (National Library of Medicine, 2015).

In case of contact with the eyes, the contact lenses should be checked and removed. Afterwards, immediately wash the eyes with plenty of cold water for at least 15 minutes.

In case of skin contact, the affected area should be rinsed immediately with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cover irritated skin with an emollient. Wash clothing and shoes before reuse. If the contact is severe, wash with a disinfectant soap and cover the contaminated skin with an antibacterial cream.

In case of inhalation, the victim should be moved to a cool place. If not breathing, artificial respiration is given.

If the compound is ingested, induce vomiting unless directed by medical personnel. It is advisable to drink large amounts of water to achieve dilution of the compound. Tight clothing such as a shirt collar, belt, or tie should be loosened.

In all cases, medical attention should be obtained immediately (Material Safety Data Sheet Calcium peroxide, 2013).

Applications

Use in soil remediation

Of all the ways you could make use of calcium peroxide, its agricultural application is the most prevalent. The fact that calcium peroxide releases oxygen when in contact with water means that it can be used as a way to rejuvenate depleted soil.

Normally after intensive agriculture or when the soil is flooded, nutrients and oxygen are lost from the soil, making it sterile.

In such a scenario, various artificial fertilizers must be used to add minerals and nutrients to the soil, in addition to other interventions to make it viable again. Calcium peroxide is essential for this process, as it is used to increase the oxygen content of the soil.

Other uses

The fact that calcium peroxide can release hydrogen peroxide when combined with acids means that it can be used as a bleaching agent.

It is widely used in this way in many paper industries. The production of hydrogen peroxide by this compound also makes it useful in the deodorization and bleaching of hair products as well as textiles.

Calcium peroxide also has a place in health care, as it can be used as an antiseptic.

Calcium peroxide is used in baking as a processing aid in bread dough mixing. The compound decomposes into oxygen once it comes in contact with water. This oxidizes and strengthens the disulfide and non-disulfide cross-links in gluten.

Environmental restoration

The fact that calcium peroxide can act as a source of oxygen means that it is useful in many ecological settings.

For example, there are many bodies of water such as lakes and ponds that have become unviable due to pollution and other related factors.

In such a scenario, calcium peroxide can be used to rejuvenate these bodies of water as well. The oxygen released by the reaction between the water and the compound restores the oxygen content of the water.

Industrial use

The role of calcium peroxide in the production of plastics is critical for the processes of catalysis and crosslinking of the different compounds that are used in the polymerization of plastics to make them hard. Calcium peroxide is also used as an initiator of these processes (Chuangjia Chemical Co, 2011).

References

1. CALCIUM PEROXIDE. (2016). Recovered from cameochemicals.noaa.gov.
2. Calcium Peroxide. (SF). Recovered from bakerpedia.com.
3. Chuangjia Chemical Co. (2011). Calcium Peroxide. Recovered from chinacjchem.com.
4. EMBL-EBI. (2014, July 28). calcium peroxide. Recovered from ebi.ac.uk.
5. Kingsfield Inc. (2011). Calcium Peroxide-CALGRO ™. Recovered from kingsfieldinc.
6. Material Safety Data Sheet Calcium peroxide. (2013, May 21). Recovered from sciencelab.com.
7. National Center for Biotechnology Information.. (2017, March 11). PubChem Compound Database; CID = 14779. Retrieved from PubChem.
8. National Library of Medicine. (2015, October 19). CALCIUM PEROXIDE. Recovered detoxnet.
9. Royal Society of Chemistry. (2015). Calcium dioxidanediide. Recovered from chemspider.com.