It normally does not ignite in air at temperatures below 115C. Sodium should be handled with respect, as it can be dangerous when improperly handled. Metallic sodium is vital in the manufacture of esters and in the preparation of organic compounds. The metal may be used to improve the structure of certain alloys, to descale metal, to purify molten metals, and as a heat transfer agent. An alloy of sodium with potassium, NaK, is also an important heat transfer agent. Sodium compounds are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries.
Soap is generally a sodium salt of certain fatty acids.
The importance of common salt to animal nutrition has been recognized since prehistoric times. Thirteen isotopes of sodium are recognized. On a volume basis, it is the cheapest of all metals. Sodium metal should be handled with great care. It cannot be maintained in an inert atmosphere and contact with water and other substances with which sodium reacts should be avoided.