Calcium hydroxide is a chemical compound with the chemical formula Ca(OH)2. It is a colourless crystal or white powder, and is created when calcium oxide (called lime or quicklime) is slaked with water. It can also be created by mixing an aqueous solution of calcium chloride and an aqueous solution of sodium hydroxide. A traditional name for calcium hydroxide is slaked lime, or hydrated lime.
If heated, calcium hydroxide decomposes into calcium oxide and water. A suspension of fine calcium hydroxide particles in water, called lime water (or milk of lime), is a medium strength base that reacts violently with acids and attacks many metals in presence of water. It will turn milky if carbon dioxide is passed through.
Because of its strong basic properties, calcium hydroxide has varied uses, such as:
* A form of lime, in water and sewage treatment and improvement of acid soils
* An ingredient in whitewash, mortar, and plaster
* An alkali used as a lye substitute in no-lye hair relaxers
* A chemical depilatory agent found in Nair
* A reagent
o In the reef aquarium hobby for adding bio-available calcium in solution for calcium-using animals such as algae, snails, hard tube worms, and corals (often referred to as Kalkwasser mix)
o In the tanning industry for neutralization of extra acid
o In the petroleum refining industry for the manufacture of additives
to oils (alkilsalicatic, sulphatic, fenatic)
o In the chemical industry for manufacture of calcium stearate
o In the food industry for processing water (for alcoholic and soft drinks)
o For clearing a brine of carbonates of calcium and magnesium in the manufacture of salt for food and pharmacopoeia
o In Native American and Latin American cooking, calcium hydroxide is called "cal." Corn cooked with cal becomes nixtamal, which is considered tastier and easier to digest.
* A filler
o In the petrochemical industry for manufacturing solid oil of various marks
o In the manufacture of brake pads
o In the manufacture of ebonite
o For preparation of dry mixes for painting and decorating
o In manufacturing mixes for pesticides
o In manufacturing a drug called "Polikar" for fighting decay (due to fungus) of fruits and vegetables during storage
* A dressing in paste form used for anti-microbial effect during a dental root canal
 Health risks
An overdose of calcium hydroxide can have dangerous symptoms, including:
* Difficulty in breathing
* Internal bleeding
* Skeletal muscle paralysis, interference with actin-myosin system.
* An increase in blood pH, which is damaging to the internal organs.
 External links
* MSDS Data Sheet.