Sodium stearate is the sodium “salt” of stearic acid and is one of the major components of soaps. It is a white, fine powder that can be found in many products and ingredients used for skin care. It acts as a thickening agent and lubricant in cosmetic products. It also helps stabilize emulsions and keeps ingredients from separating in a cream, lotion or other product. Sodium stearate is non-toxic and hypoallergenic.
It is also a natural ingredient in the fats and oils of plant origin. It is considered halal if it is sourced from vegetable sources, such as rapeseed and palm oil. Lush’s own vegetable based sodium stearate is certified halal by an independent halal auditor. It is also kosher pareve and can be purchased from several suppliers who offer different grades of kosher parve sodium stearate, from rapeseed oil to sunflower oil.
To determine if a product contains sodium stearate, heat 50 mL of alcohol to the same temperature, +-5, as that attained when the pink endpoint is reached in the titration of the test specimen. Add 3 drops of phenolphthalein TS and sufficient 0.020 N sodium hydroxide to produce a faint pink color. Stir the mixture to dissolve the stearate and add 2.00 g of Sodium Stearate, and shake vigorously for 10 minutes. The solution is acid free if it remains clear.
To determine if a product is alcohol soluble, titrate 1.0 g with 25 mL of alcohol. The solution is alcohol-soluble if it evaporates to dryness in less than 4 hours at 105°C and is clear or only slightly opalescent.