Stearic acid is a fatty acid with 18 carbon chain and IUPAC name as octadecanoic acid, is found in animal derivatives and vegetable fats. This waxy solid has C17H35CO2H chemical formula. The name has been derived from Greek word στέαρ “stéar” which means tallow. Salts and esters of stearic acid are known as stearates. It is used in various cosmetics and personal care products as a surfactant face ingredient and emulsifier. It is used as a base to manufacture other fatty acid ingredients used as emollients, emulsifiers and lubricants. It is used as an ingredient in plastics, candles, oil pastels, dietary supplements and softening rubber. It is used as an ingredient in soaps made in vegetable oil and also used to harden product.
Stearic acid in nature occurs as mixed triglyceride or fat with other long chain acids and as ester of fatty alcohol. It is abundantly found in animal fat, lard and tallow. In cosmetics, it is used to form a stable base for lotions, deodorants and creams. It also binds and thicken products which adhere smoothly to the skin and has long shelf life. In food products, it is stable during frying and storage. Spreads, margarines and shortenings are formulated with it. Though it is a saturated fat, it has low effect on levels of blood cholesterol.
Other uses include it is used to coat metal powders such as aluminium and iron which are used in fireworks allowing them to be stored for longer time periods. It is used to prevent oxidation and rust in some metal polishes which occur on metal parts of tools.
Food Sources
| Food name | Weight (g) | Stearic acid (g) |
| Pork | 113 | 12.871 |
| Pilinuts | 120 | 10.978 |
| Kielbasa | 370 | 10.730 |
| Brazilnuts | 133 | 8.305 |
| Pimento | 140 | 5.306 |
| Sheanut | 13.6 | 5.277 |
| Sesame seeds | 150 | 4.966 |
| Colby cheese | 132 | 4.792 |
| Muenster cheese | 132 | 4.711 |
| Watermelon seeds | 108 | 4.643 |
| Monterey jack cheese | 132 | 4.518 |
| Swiss cheese | 132 | 4.219 |
| Salami | 113 | 4.023 |
| Cocoa | 86 | 3.655 |
| Fontina cheese | 132 | 3.505 |
| Egg | 85 | 3.378 |
| Macadamia nuts | 134 | 3.121 |
| Bratwurst | 85 | 2.915 |
| Sunflower seeds | 128 | 2.831 |
| Mozzarella cheese | 132 | 2.743 |
Side effects
Though considered safe, stearic acid might cause several side effects in humans. It could cause skin irritations with symptoms of redness, severe itching and swelling. It could cause rash like symptoms which is similar to tiny red spots. It makes skin sensitive to substance and direct exposure to sun. Moreover, it causes hive like spots in skin leading to blisters that could lead to skin damage. It could be harmful to immune, digestive, ocular, integumentary and respiratory systems.
References:
https://en.wikipedia.org/wiki/Stearic_acid
https://www.britannica.com/science/stearic-acid
https://www.foodsweeteners.com/stearic-acid-side-effects/
https://www.wisegeek.com/what-are-the-different-uses-of-stearic-acid.htm