- Sodium chloride (NaCl), commonly known as table salt, is one of the most widely used and essential chemical compounds in the world.
- It is composed of two elements—sodium (Na) and chlorine (Cl)—which form a crystalline ionic compound. In its pure form, sodium chloride is a white, crystalline solid that is highly soluble in water and has a characteristic salty taste. It occurs abundantly in nature, especially in seawater, salt lakes, and mineral deposits, and is obtained through evaporation of seawater, mining of rock salt (halite), and solution mining.
- In daily life, sodium chloride is best known for its culinary and preservative roles. It is a fundamental seasoning used to enhance the flavor of food, and it also acts as a preservative by inhibiting microbial growth through dehydration and osmotic pressure. Salt-curing of meats and fish is one of the oldest preservation methods, and sodium chloride remains a key ingredient in processed and packaged foods. It also plays a vital role in regulating fluid balance and nerve function in the human body. Sodium and chloride ions are crucial electrolytes involved in nerve impulse transmission, muscle contraction, and hydration.
- In medicine and healthcare, sodium chloride has several applications. Saline solutions (typically 0.9% NaCl in water) are widely used for intravenous infusions to rehydrate patients, restore electrolyte balance, and deliver medications. Hypertonic and hypotonic saline solutions are also used for specific clinical purposes, such as reducing intracranial pressure or managing hyponatremia. Additionally, sodium chloride is used in wound cleaning, eye drops, and nasal rinses, owing to its isotonic and non-irritating nature when properly diluted.
- In industrial and chemical manufacturing, sodium chloride is a key raw material used in the chlor-alkali process, where it is electrolyzed to produce chlorine gas, hydrogen gas, and sodium hydroxide (caustic soda)—three critical chemicals used in countless applications ranging from plastics and disinfectants to paper production. Sodium chloride is also used in soap making, textile processing, and metal refining. It serves as a flux in metallurgy and is utilized in the de-icing of roads and highways, where it lowers the freezing point of water to prevent ice formation and improve safety during winter conditions.
- In agriculture and water treatment, sodium chloride is used to regenerate ion exchange resins in water softeners and to manage livestock nutrition. Animals, like humans, require sodium and chloride ions for metabolic function, and salt licks or fortified feeds help meet their dietary needs.
- While sodium chloride is indispensable, excessive consumption, especially through processed foods, is associated with health risks such as high blood pressure (hypertension), which increases the risk of heart disease and stroke. Health authorities recommend limiting sodium intake, promoting awareness of “hidden” salt in processed foods, and encouraging balanced dietary habits.
