What is it?
An ester of palmitic acid, a saturated fatty acid that is a major component of palm oil, and isopropyl alcohol. It is an emollient that softens skin and helps products spread, and it is used in lotions, creams, makeup, hair products and bath products. Like other alkyl esters, it can help other ingredients pass into the skin.
Key information
- The CIR Expert Panel found it safe as used in 1982 and reaffirmed that in 2005; in 2013 it included it among alkyl esters that are safe when formulated to be non-irritating.
- In 2013 it was reported in 1,125 cosmetic products, at up to 60 percent.
- Undiluted, it did not cause allergic sensitization in a repeat patch test of 102 people.
- It scored 4 out of 5 in a 1989 rabbit-ear comedogenicity survey, a test more sensitive than human skin.
More information
Like most alkyl esters, isopropyl palmitate is made by reacting a fatty acid, here palmitic acid, with an alcohol, here isopropyl alcohol. Palmitic acid makes up about 44 percent of the fat in palm oil and also occurs in meat and dairy fat, cocoa butter and olive oil. The label does not say where the palmitic acid came from.
The Cosmetic Ingredient Review (CIR) Expert Panel found isopropyl palmitate safe as used in 1982, reaffirmed that in 2005, and in 2013 included it among 237 alkyl esters it concluded are safe when formulated to be non-irritating. It was then used in 1,125 products, at up to 60 percent. In three 24-hour patch tests of the undiluted ingredient on 160 people, nearly all irritation scores were zero, with five slight reactions. Undiluted, it did not cause allergic sensitization in a repeat patch test of 102 people, and a formula with 45.6 percent was not sensitizing, phototoxic or photoallergenic. A cream with 10 percent was moderately irritating to guinea pig skin but well tolerated on human skin.
Its reputation as a pore-clogger comes from animal tests of the raw ingredient. In a 1989 survey that applied ingredients daily to the sensitive inner ear of rabbits for two weeks, it scored 4 of 5 for pore clogging and 1 of 5 for irritation. The author called the model extremely sensitive, and a 2006 study that tested finished products on human skin concluded that products made with comedogenic ingredients are not necessarily comedogenic. Like other alkyl esters, it can help other ingredients pass into the skin, which the CIR flags for formulators. If you are acne-prone, how a product behaves on your skin is the better guide.
Sources: Cosmetic Ingredient Review: Amended safety assessment of alkyl esters as used in cosmetics (2013); Journal of the Society of Cosmetic Chemists (1989): Comedogenicity and irritancy of commonly used ingredients in skin care products; Journal of the American Academy of Dermatology (2006): A re-evaluation of the comedogenicity concept; Frontiers in Physiology (2017): Palmitic acid: physiological role, metabolism and nutritional implications
