Salt , or sodium chloride (NaCl), is a mineral vital for both human and animal health, as well as various industries. Also known as common salt, its mineral form is called halite or rock salt. Table salt is used globally as a seasoning. Salt is also used as a preservative in the meat-packing, sausage-making, fish-curing, and food-processing industries. The chemical industry requires salt to manufacture chemicals like sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, and chlorine. Seawater averages about 3% salt, but concentrations range from 1% to 5%. If the world's oceans dried up, they would yield approximately 4.5 million cubic miles of rock salt.

What is sodium chloride used for?

Sodium chloride , or common salt, is a mineral with many uses for humans, animals, and industry. As a seasoning and preservative, it enhances flavor and inhibits spoilage in meatpacking, food processing, and cooking. Salt is also essential for health; it can prevent goiters when it's iodized. The chemical industry relies on salt to make sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, and chlorine. It is also used to de-ice roads, soften water, and make soap, glaze, and porcelain enamel.

How is salt found in nature?

Salt , or sodium chloride, is found in nature as crystalline rock salt , also known as halite. It is also all around us in seawater , which averages about 3 percent salt. Salt is obtained through evaporation of seawater or from mining rock salt . Rock salt deposits come from the evaporation of ancient seas.

Why is salt important for the human body?

Sodium chloride, or salt, is vital for the human body because sodium salts are present in almost all biological material. Sodium and potassium maintain electrolyte balance inside and outside of cells through active transport. The minimum sodium requirement for mammals is about 1–2 grams a day, which results in body tissues having an average sodium content of 0.24 percent. Chlorides from salt play a key role in maintaining electrical neutrality and pressure of extracellular fluids, as well as the body's acid-base balance. Because levels of chlorine closely parallel levels of sodium, the best source of chlorine is ordinary table salt, though chlorides are also naturally contained in meat, milk, and eggs. However, excessive salt intake can be harmful, increasing the risk of health problems like hypertension and heart disease . The WHO suggests a drinking water guideline of 200 parts per million, while the U.S. EPA recommends a sodium advisory of 30–60 parts per million for drinking water.

How is table salt different from other salts?

Table salt, known chemically as sodium chloride (NaCl), is a mineral essential for both human and animal health and is universally used as a seasoning. While "salt" can refer to a class of chemical compounds, table salt is distinguished by its high purity and fine-grained form. To ensure table salt remains free-flowing, even when exposed to air, small amounts of sodium aluminosilicate, tricalcium phosphate, or magnesium silicate are often added. Additionally, iodized salt , with added potassium iodide, is common in areas lacking iodine in the diet to prevent thyroid issues.

What are some effects of too much salt in your diet?

Consuming too much salt (sodium chloride) can lead to several health issues. High sodium intake stresses the kidneys and is linked to hypertension , increasing the risk of heart disease, stroke, and kidney disease. A high-salt diet can also cause calcium loss and may contribute to dementia. It's generally recommended to limit sodium intake to no more than 2,400 mg daily, which is just over a teaspoon of salt. This can be achieved by limiting the amount of salt used in cooking, avoiding adding salt at the table, and reducing consumption of highly processed and fast foods.

salt

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Cluster of translucent, white salt crystals with sharp cubic shapes viewed under a microscope at high magnification against a dark background.

A mound of white sea salt drying on dark red clay in the salt marshes of Guerande, Brittany, France, with shallow evaporation ponds in the background.

salt

sodium chloride

Also known as: common salt, sodium chloride, table salt

Written by

Frank Osborne WoodAll

Fact-checked by

Britannica Editors

Last updated

Nov. 1, 2026 •History

Top Questions

What is salt?
Salt, or sodium chloride (NaCl), is a mineral vital for both human and animal health, as well as various industries. Also known as common salt, its mineral form is called halite or rock salt.

Table salt is used globally as a seasoning. Salt is also used as a preservative in the meat-packing, sausage-making, fish-curing, and food-processing industries. The chemical industry requires salt to manufacture chemicals like sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, and chlorine.

Seawater averages about 3% salt, but concentrations range from 1% to 5%. If the world's oceans dried up, they would yield approximately 4.5 million cubic miles of rock salt.
5 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What is sodium chloride used for?
Sodium chloride, or common salt, is a mineral with many uses for humans, animals, and industry.

As a seasoning and preservative, it enhances flavor and inhibits spoilage in meatpacking, food processing, and cooking. Salt is also essential for health; it can prevent goiters when it's iodized.

The chemical industry relies on salt to make sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, and chlorine. It is also used to de-ice roads, soften water, and make soap, glaze, and porcelain enamel.
5 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How is salt found in nature?
Salt, or sodium chloride, is found in nature as crystalline rock salt, also known as halite. It is also all around us in seawater, which averages about 3 percent salt. Salt is obtained through evaporation of seawater or from mining rock salt. Rock salt deposits come from the evaporation of ancient seas.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Why is salt important for the human body?
Sodium chloride, or salt, is vital for the human body because sodium salts are present in almost all biological material. Sodium and potassium maintain electrolyte balance inside and outside of cells through active transport. The minimum sodium requirement for mammals is about 1–2 grams a day, which results in body tissues having an average sodium content of 0.24 percent.

Chlorides from salt play a key role in maintaining electrical neutrality and pressure of extracellular fluids, as well as the body's acid-base balance. Because levels of chlorine closely parallel levels of sodium, the best source of chlorine is ordinary table salt, though chlorides are also naturally contained in meat, milk, and eggs.

However, excessive salt intake can be harmful, increasing the risk of health problems like hypertension and heart disease. The WHO suggests a drinking water guideline of 200 parts per million, while the U.S. EPA recommends a sodium advisory of 30–60 parts per million for drinking water.
6 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How is table salt different from other salts?
Table salt, known chemically as sodium chloride (NaCl), is a mineral essential for both human and animal health and is universally used as a seasoning. While "salt" can refer to a class of chemical compounds, table salt is distinguished by its high purity and fine-grained form.

To ensure table salt remains free-flowing, even when exposed to air, small amounts of sodium aluminosilicate, tricalcium phosphate, or magnesium silicate are often added. Additionally, iodized salt, with added potassium iodide, is common in areas lacking iodine in the diet to prevent thyroid issues.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are some effects of too much salt in your diet?
Consuming too much salt (sodium chloride) can lead to several health issues. High sodium intake stresses the kidneys and is linked to hypertension, increasing the risk of heart disease, stroke, and kidney disease. A high-salt diet can also cause calcium loss and may contribute to dementia. It's generally recommended to limit sodium intake to no more than 2,400 mg daily, which is just over a teaspoon of salt. This can be achieved by limiting the amount of salt used in cooking, avoiding adding salt at the table, and reducing consumption of highly processed and fast foods.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

salt (NaCl), mineral substance of great importance to human and animal health, as well as to industry. The mineral form halite, or rock salt, is sometimes called common salt to distinguish it from a class of chemical compounds called salts.

Properties of common salt are shown in the Click Here to see full-size table properties of salt table. Salt is essential to the health of both people and animals. Table salt, used universally as a seasoning, is fine-grained and of high purity. To ensure that this hygroscopic (i.e., water-attracting) substance will remain free-flowing when exposed to the atmosphere, small quantities of sodium aluminosilicate, tricalcium phosphate, or magnesium silicate are added. Iodized salt—that is, salt to which small quantities of potassium iodide have been added—is widely used in areas where iodine is lacking from the diet, a deficiency that can cause swelling of the thyroid gland, commonly called goitre. Livestock also require salt; it is often made available in solid blocks.

The meat-packing, sausage-making, fish-curing, and food-processing industries use salt as a preservative or seasoning or both. It is employed for curing and preserving hides and as a brine for refrigeration.

In the chemical industry, salt is required in the manufacture of sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, chlorine, and many other chemicals. Salt is also employed in soap, glaze, and porcelain enamel manufacture and enters into metallurgical processes as a flux (a substance promoting fusing of metals).

When applied to snow or ice, salt lowers the melting point of the mixture. Thus, large amounts are used in northern climates to help rid thoroughfares of accumulated snow and ice. Salt is used in water-softening equipment that removes calcium and magnesium compounds from water.

Ceviche. Peruvian ceviche (sebiche). Raw seafood dish with lime, cilantro, peppers, plantains. Cuisine, food

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History of use

In some parts of the Western Hemisphere and in India, the use of salt was introduced by Europeans, but in parts of central Africa it is still a luxury available only to the rich. Where people live mainly on milk and raw or roasted meat (so that its natural salts are not lost), sodium chloride supplements are unnecessary; nomads with their flocks of sheep or herds of cattle, for example, never eat salt with their food. On the other hand, people who live mostly on cereal, vegetable, or boiled meat diets require supplements of salt.

The habitual use of salt is intimately connected with the advance from nomadic to agricultural life, a step in civilization that profoundly influenced the rituals and cults of almost all ancient nations. The gods were worshipped as the givers of the kindly fruits of the earth, and salt was usually included in sacrificial offerings consisting wholly or partly of cereal elements. Such offerings were prevalent among the Greeks and Romans and among a number of the Semitic peoples.

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Covenants were ordinarily made over a sacrificial meal, in which salt was a necessary element. The preservative qualities of salt made it a peculiarly fitting symbol of an enduring compact, sealing it with an obligation to fidelity. The word salt thus acquired connotations of high esteem and honour in ancient and modern languages. Examples include the Arab avowal “There is salt between us,” the Hebrew expression “to eat the salt of the palace,” and the modern Persian phrase namak ḥarām, “untrue to salt” (i.e., disloyal or ungrateful). In English the term “salt of the earth” describes a person held in high esteem.

Salt contributes greatly to our knowledge of the ancient highways of commerce. One of the oldest roads in Italy is the Via Salaria (Salt Route) over which Roman salt from Ostia was carried into other parts of Italy. Herodotus tells of a caravan route that united the salt oases of the Libyan Desert. The ancient trade between the Aegean and the Black Sea coast of southern Russia was largely dependent on the salt pans (ponds for evaporating seawater to obtain salt) at the mouth of the Dnieper River and on the salt fish brought from this district.

China, the United States, India, Germany, Canada, and Australia are the world’s largest salt producers in the early 21st century.

Frank Osborne Wood

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History of use