Sodium stearate


Sodium stearate is the sodium salt of stearic acid. This white solid is the most common soap. It is found in many types of solid deodorants, rubbers, latex paints, and inks. It is also a component of some food additives and food flavorings.

Production

Sodium stearate is produced as a major component of soap upon saponification of oils and fats. The percentage of the sodium stearate depends on the ingredient fats. Tallow is especially high in stearic acid content, whereas most fats only contain a few percent. The idealized equation for the formation of sodium stearate from stearin follows:
Sodium stearate can also be made by neutralizing stearic acid with sodium hydroxide.

Safety and environmental considerations

Stearate salts, as found in many commercial soaps are of low toxicity, hence their wide use in domestic settings. They do pose some problems for wastewater treatment as they biodegrade relatively slowly and impose a high biological [oxygen demand].