Salt, also sodium chloride, chemical compound that has the formula NaCl.
Most people probably think of salt as simply that white granular food seasoning found in a salt shaker on virtually every dining table. It is that, surely, but it is far more. It is an essential element in the diet of not only humans but of animals, and even of many plants. It is one of the most effective and most widely used of all food preservatives. Its industrial and other uses are almost without number. In fact, salt is involved in almost all aspects of human activity.
The fact is that throughout history has been such an important element of life that it has been the subject of much folklore. It served as money at various times and places, and it has been the cause of bitter warfare.
Salt has more than 14,000 known uses.
The greatest single use for salt is as a feedstock for the production of chemicals. The chlor-alkali industry uses salt, primarily as salt in brine from captive brine wells, to produce chlorine and caustic soda. Demand for salt in to produce chemicals fell from 25 million metric tons in 1974 to a low of 16.7 million metric tons in 1992. However, chemical use rebounded in 1994 to 18.4 million metric tons. Much of the decreased demand for chlorine was attributed to environmental concerns about dioxins. Salt is also used to make sodium chlorate and metallic sodium by electrolysis and, sodium sulfate and hydrochloric acid by reacting with sulfuric acid.
Salt is essential not only to life, but to good health. Doctors often recommend replacing water and salt lost in exercise (see advice for ultraendurance athletes). Increased salt intakes have been used successfully to combat Chronic Fatigue Syndrome, with some very satisfying results. Dramatic deficiencies or "excessive" sodium intakes have been associated with other conditions and diseases, such as stomach cancer. The most talked-about is the association of dietary sodium and elevated blood pressures (hypertension).