Sodium Chloride
Sodium chloride or table salt is a mineral substance belonging to the larger class of compounds called ionic salts. Salt in its natural form is known as rock salt or halite. Salt is present in vast quantities in the ocean, which has about 35 grams of sodium chloride per litre, corresponding to a salinity of 3.5%. Salt is essential for animal life, and saltiness is one of the basic human tastes. The tissues of animals contain larger quantities of salt than do plant tissues. Salt is one of the oldest and most ubiquitous of food seasonings, and salting is an important method of food preservation. Salt is produced from salt mines or by the evaporation of seawater or mineral-rich spring water in shallow pools. Salt is used in many industrial processes and in the manufacture of polyvinyl chloride, plastics, paper pulp and many other consumer products. Of the global annual production of around 200,000,000 tonnes of salt, only 6% is used for human consumption. Other uses include water conditioning, highway de-icing and various agricultural applications. For humans, salt is a major source of sodium. Sodium is essential to life: it helps nerves and muscles to function correctly, and it is one of the factors involved in the regulation of water content.