Calcium hydroxide

Calcium hydroxide, represented by the chemical formula Ca(oh)2, is a compound created by mixing calcium oxide with water. The result is a crystal white power with strong alkaline properties. The calcium hydroxide has a vast array of usage. For instance, it’s used in the manufacture of hair products, in the dental industry, food manufacturing, in leather production etc.

Dental Antimicrobial solution
The National Institute of Health promotes Calcium Hydroxide as a commonly used ingredient in the manufacture of antimicrobial root canal sealers. Ca(OH)2 is the main substance used when preparing the protective layer known in medical terms as the ”Apical barrier”. Apical barriers are often used in situations where endodontic surgery is difficult to perform. The calcium hydroxide disinfects the tooth by killing the bacteria. Furthermore, it’s used as a temporary means for reducing pain and swelling as the patient waits for endodontic surgery. Its high pH makes Ca(OH)2 a perfect choice for a temporary antibacterial root canal filler.

Application of hydrated lime in the manufacture of hair products

Some hair relaxers use calcium hydroxide as an active alkaline ingredient. These are liquids or creams used to straighten curly hair during styling. Many hair relaxers contain lye, which is a powerful caustic solution. Unfortunately, lye damages both the hair and skin, and more people are shunning hair relaxers with this compound. Instead, they are going for hair relaxers manufactured with calcium hydroxide as a substitute for lye.

Ca(OH)2 straightens curly hair just like lye. Studies conducted by Cornell Medical research show that calcium hydroxide disintegrates sidulfide bonds that hold together cysteines. Cysteines are amino acids which occur naturally in curly hair. Unless they are broken, the hair will remain in that condition. Calcium hydroxide breaks and seals off those bonds so that the physical structure of the hair is altered completely.

In leather production
Leather cannot be used with hair on it. Animal hair has to be separated from the hide before the skin can be put to effective use. A mixture of warm water and calcium hydroxide is used during this operation, where fresh hide is dipped inside and stirred frequently for 4 days. This process loosen the structure of the hair such that it can be removed by hand. When that happens, the hide is dipped in ammonium sulfate solution to counter the caustic effect of calcium hydroxide and to balance the pH as well.

In food production
It may be used in the processing of some alcoholic and soft drinks. Calcium hydroxide is one of the ingredients found in Lutefisk, a traditional dish native to Swedish people. According to Nordic Recipe Archive, this diet is comprised on stockfish soaked in cold water for several days. Once the fish is soaked, it’s dipped in a solution of water and lye or other caustic solutions such as Calcium hydroxide. The aim is to break down the proteins inside the fish to result in a delicate fish diet with a jelly-like consistency. Furthermore, it makes the fish taste caustic, so the fish has to be dipped in cold water for additional days before it can be eaten.

The calcium hydroxide has a number of uses in the food industry as well. It plays a key role in the separation of sugar from sugar cane. In native American cooking, it’s called ”Cal”. They cook cone with cal and they call it nixtamal. This diet is considered tastier and easier to digest. So it looks like the food industry is benefiting more than any other industry.

The slack lime may be used in the sea as well. Research shows that it reduces the greenhouse effect as well as the amount of atmospheric pressure that’s in the air. However, when it’s used this way, it has to be produced in massive quantities which is quite expensive.

Some households use it as an insecticide. Most crawling and flying insects die when they come into contact with calcium hydroxide. Insects that react to it include bees, beetles, flees, and grubs. It may offer a cost-effective measure of eliminating these insects easily.

There are many uses of the calcium hydroxide today. It manufactures your car break paddles, and paints your beautiful home as well. There is practically no industry that doesn’t use it.

However, despite the vast uses of calcium hydroxide, it poses health risks to people who handle it more often. It may cause skin burns, blindness when it comes into contact with the eyes and it could also damage your lungs when inhaled.



Ca(OH)2 stands for material safety data sheet of calcium hydroxide – a very important document that shows general safety information about this chemical.

Chemical Product and Company Identification

The chemical name is calcium hydroxide
The chemical formula is Ca(OH)2
Synonyms of calcium hydroxide are Calcium hydroxide, hydrated lime, builders lime, slack lime, pickling lime, slaked lime.

Composition and Information on Ingredients
The lethal dose is around 7300mg/kg. Studies are made with rats and mice.

Hazards Identification

Ca(OH)2 is hazardous in eye contact, skin contact, ingestion and inhalation. It can easily damage the tissues and the damage depends on the length of the contact with the tissue. Calcium hydroxide is a strong irritant – can cause blindness when contacts the conjunctiva and irritation and blistering when contacts the skin and mucosa.


Ca oh 2 details and chemical formula

The calcium hydroxide is produced by mixing lime (CaO – calcium oxide) with water. Another name for this reaction is slaking. This is the cheapest way to produce CaOh2 which is used in a number of industries.

CaO + H2O = Ca(OH)2

Ca(oh)2 is a strong base. Therefore it can react with acids. The reaction is called neutralization:
The normal products from the neutralization are water and a salt.
Ca(oh)2 + HCl = CaCl2 + 2 H2O

You can also produce Ca(OH)2 in the laboratory by mixing aqueous solution of calcium chloride CaCl2 and sodium hydroxide NaOH:

CaCl2 + 2NaOH = Ca(OH)2+ 2NaCl

Ca(oh)2 has a polymeric structure like all the alkaline earth metal hydroxides.



Ca Oh 2 a.k.a Calcium hydroxide, hydrated lime, builders lime, slack lime, pickling lime, slaked lime is an inorganic chemical used in many industries. Obtaining calcium hydroxide is cheap and doesn’t need special equipment since Ca(OH)2 is not a toxic agent. Because of its -OH radicals the chemical is used for raising the pH of the water. It neutralizes the acids and regulates the pH. A typical characteristic for Ca oh 2 is that it doesn’t raise the pH to a very high level. That is because it achieves an equilibrium shown in the next formula:

Ca(OH)2 = CaO + H2O

It regulates the pH, keeps it high but not too much. Ca(oh)2′s self-regulation makes it perfect for water treatment and reducing the H+ in the water. These ions make the pipes corrode. It is either a colorless crystal or white powder easily soluble in water:

Ca(OH)2 = Ca2+ + 2OH-


Calcium hydroxide is produced by mixing water (H2O) with lime (CaO):

CaO + H2O = Ca(OH)2

This is the cheapest and most efficient method to produce slaked lime. Another way to obtain hydrated lime is by mixing sodium hydroxide with calcium chloride. Both NaOH and CaCl2 must be in aqueous solutions:

2NaOH + CaCl2 =2NaCl + Ca(OH)2


In the presence of carbon dioxide, calcium hydroxide can be carbonated – the result is calcium carbonate and water:

Ca(OH)2 + CO2 = CaCO3 + H2O





Ca + 2(H2O) = Ca(OH)2 + H2

2HNO3 + Ca(OH)2 = Ca(NO3)2 + 2H2O

2H3PO4 + 3Ca(OH)2 = 6H2O + Ca3(PO4)2

3H3PO4 + 5Ca(OH)2 = Ca5(PO4)3(OH) + 9H2O

HCl + Ca(OH)2 = CaCl2 + H2O