Peg-16 Castor Oil Dioleate: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Peg-16 Castor Oil Dioleate?

Peg-16 Castor Oil Dioleate is a plant derived ingredient made by reacting natural castor oil with ethylene oxide until an average of 16 ethylene glycol units have attached to each castor oil molecule. This process, called ethoxylation, turns the thick sticky oil into a lighter water soluble substance that can act as a gentle surfactant in cosmetics. The finished material is a monoester of oleic acid, one of the main fatty acids found in castor beans, combined with the polyethylene glycol chain.

The cosmetic industry began experimenting with ethoxylated castor oils in the mid 1900s while searching for milder alternatives to soap based cleansers. Peg-16 Castor Oil Dioleate gained popularity because it could disperse oil and dirt without stripping the skin, an advantage that fit the growing demand for gentler personal care products. Today it is manufactured in controlled facilities where the degree of ethoxylation, purity and safety parameters are carefully monitored.

You will most often see Peg-16 Castor Oil Dioleate in facial cleansers, micellar waters, liquid hand soaps, body washes, shampoos, makeup removers and baby bath formulas. It can also appear in scrub bases, cleansing balms and some sheet mask essences where a light yet effective cleansing action is desired.

Peg-16 Castor Oil Dioleate’s Cosmetic Benefits/Uses

Its main job in a formula is simple yet important: cleansing. Peg-16 Castor Oil Dioleate lowers the surface tension between water and oil so that grime, sweat and makeup are lifted from the skin or hair and rinsed away easily. Because the molecule contains both fatty acid and polyethylene glycol portions it can attract oil while remaining soluble in water, which allows for thorough cleaning that still feels mild and non stripping.

Who Can Use Peg-16 Castor Oil Dioleate

This cleansing agent is considered gentle enough for most skin types including oily, combination, normal and dry skin. Its mild nature means it usually does not irritate sensitive skin, although very reactive or allergy-prone users should still approach with caution and watch for any discomfort after use.

The ingredient is derived from plant-based castor oil and does not rely on animal sources, so formulations using it are typically suitable for both vegans and vegetarians. As always it is smart to review the full ingredient list since other animal-derived additives could be present in the same product.

Current safety data shows no specific risk linked to topical use during pregnancy or breastfeeding when the ingredient is used as intended in cosmetic products. This is not medical advice. Expectant or nursing mothers should consult their doctor about any skincare routine to be safe.

Peg-16 Castor Oil Dioleate does not make skin more sensitive to sunlight, so it is not known to cause photosensitivity. Daily sun protection is still recommended for overall skin health.

Potential Side Effects/Adverse Reactions

Responses to Peg-16 Castor Oil Dioleate can vary from person to person. The points below outline potential but uncommon side effects when the ingredient is applied to skin or hair. When used correctly in well formulated products most people will not notice any problems.

  • Mild stinging or redness in very sensitive skin, usually short lived after rinsing
  • Dryness or tight feeling if the surrounding formula has a high surfactant load or low moisturizers
  • Contact dermatitis in individuals allergic to castor derivatives or polyethylene glycol compounds
  • Eye irritation if high concentrations come in direct contact with the eyes

If any discomfort, rash or irritation persists stop use and seek advice from a healthcare professional

Comedogenic Rating

Rating: 1 / 5 (low)

Peg-16 Castor Oil Dioleate is highly water soluble and largely rinses off the skin, leaving little residue that could block pores. While raw castor oil can be mildly comedogenic, the ethoxylation process changes its structure and dramatically lowers the chance of clogging. For most people, including those prone to acne or breakouts, this ingredient is unlikely to cause comedones when used in typical cleanser or rinse-off formulas.

If breakouts do occur, they are more likely due to heavier oils, waxes or occlusives elsewhere in the product rather than Peg-16 Castor Oil Dioleate itself. Always consider the full ingredient list and how long the product stays on the skin.

Summary

Peg-16 Castor Oil Dioleate is a plant derived surfactant that lifts oil, makeup and daily grime without stripping moisture. Its dual nature—fatty acid tail plus polyethylene glycol chain—lets it bind to dirt yet rinse away with water, giving formulas gentle cleansing power.

It is not the flashiest ingredient on the market, but formulators value it for its reliability, mildness and compatibility with a wide range of skin types. You will mostly find it in everyday cleansers, micellar waters and baby washes rather than in trend-driven serums.

Safety reviews show it is well tolerated, with low irritation and low comedogenic risk when used as directed. As with any new skincare product, a simple patch test is a smart move to make sure your skin agrees with the full formula.

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