What Is Dea-Oleth-3 Phosphate?
Dea-Oleth-3 Phosphate is a synthetic ingredient created by reacting naturally sourced oleyl alcohol with about three units of ethylene oxide, then attaching a phosphate group and neutralizing it with diethanolamine. The result is a salt that mixes the oil friendly part of oleyl alcohol with water friendly phosphate and amine groups, giving it a balanced structure that works well in skin care formulas. It first appeared in cosmetic catalogs in the late 1980s when formulators were looking for gentler surfactants that could also stabilize emulsions. Today it is produced in large batches through controlled ethoxylation and phosphorylation steps, followed by purification to remove excess reactants.
You will most often see Dea-Oleth-3 Phosphate in facial cleansers, micellar waters, exfoliating scrubs, lightweight moisturizers, makeup removers, sheet mask essences and scalp rinses where a mild but effective cleanser or stabilizer is needed.
Dea-Oleth-3 Phosphate’s Cosmetic Benefits/Uses
Formulators choose this multifunctional ingredient for two main reasons
- Cleansing: Its surfactant nature lifts away dirt, oil and residue without stripping the skin so products feel gentle yet effective even on sensitive complexions
- Emulsifying: It helps oil and water stay blended which keeps lotions, creams and fluid cleansers smooth stable and easy to spread while preventing separation during shelf life
Who Can Use Dea-Oleth-3 Phosphate
This ingredient suits most skin types, especially normal, combination and oily skin that need a cleanser that will not feel harsh. Sensitive skin usually tolerates it well since it is milder than many sulfates, though people with very dry or already compromised skin barriers might find any surfactant a bit dehydrating if overused. Because Dea-Oleth-3 Phosphate is made from plant-derived oleyl alcohol and fully synthetic processing aids, it contains no animal ingredients so it is considered vegan and vegetarian friendly.
Current safety data show no specific risks for women who are pregnant or breastfeeding when the ingredient is used as intended in rinse-off or leave-on cosmetics. This is not medical advice and anyone who is pregnant or nursing should check with a healthcare professional before starting a new product just to be safe.
The molecule itself does not make skin more sensitive to sunlight, so no extra sun precautions are needed beyond your usual SPF habits. It also plays nicely with most other common skincare actives and preservatives, so formulators can add it without worrying about unwanted chemical reactions.
Potential Side Effects/Adverse Reactions
Responses to topical Dea-Oleth-3 Phosphate vary from person to person. The points below list potential side effects, but they are uncommon when the ingredient is used at the low levels found in finished products and when the product has been formulated correctly.
- Mild redness or stinging during use, more likely on very sensitive skin
- Temporary tight or dry feeling if the formula is left on the skin too long or used too frequently
- Rare allergic contact dermatitis resulting in itching or small rash
- Eye irritation if a cleanser containing it gets into the eyes
If you notice any of these reactions stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
Dea-Oleth-3 Phosphate carries a small fatty chain from oleyl alcohol but it is paired with highly water-attracting phosphate and amine groups, which keeps the molecule largely water soluble. It is used at low concentrations, often in rinse-off products, so it rarely lingers on the skin long enough to clog pores. For these reasons it earns a low score of 1.
Suitable for acne-prone or breakout-prone skin in most cases.
As with any surfactant, over-cleansing can disrupt the skin barrier and indirectly trigger more oil production, so moderation is still wise.
Summary
Dea-Oleth-3 Phosphate cleanses by surrounding oil and debris so they can be rinsed away and it stabilizes emulsions by positioning its oil-loving tail in oils and its water-loving head in water, keeping everything blended. These dual talents make it a handy choice for gentle facial washes micellar waters and fluid lotions.
The ingredient is modestly popular; it shows up in niche and mid-range formulas where brands want an alternative to harsher sulfates but it is not as mainstream as classics like sodium laureth sulfate.
Current data label it as low risk with minimal irritation potential when used as intended. Even so skin is personal so patch test any new product that contains it before full use to stay on the safe side.