What Is Dioleth-8 Phosphate?
Dioleth-8 Phosphate is a synthetic ingredient created by reacting natural oleyl alcohol, a fatty alcohol derived from vegetable oils, with ethylene oxide and then linking the result to phosphoric acid. The process adds about eight ethoxy units to each oleyl molecule, producing a molecule that has both oil-loving and water-loving parts. This dual nature makes it valuable in modern cosmetics, where it has been used since the late 20th century as formulators looked for milder alternatives to traditional soaps. Manufacture takes place in controlled reactors where temperature and pH are carefully managed to attach the ethoxy units and finally esterify with phosphoric acid, yielding a clear to slightly hazy liquid.
Because it can pull together oily and watery ingredients, Dioleth-8 Phosphate appears in a wide variety of personal care products. You are most likely to find it in facial cleansers, micellar waters, makeup removers, lightweight moisturizers, sheet masks, body washes and even some hair conditioners where gentle cleansing or improved texture is needed.
Dioleth-8 Phosphate’s Cosmetic Benefits/Uses
This ingredient brings more than one useful property to a formulation
- Cleansing: Its amphiphilic structure surrounds dirt and excess sebum so they can be rinsed away with water, giving products a gentle yet effective washing action that leaves skin feeling refreshed without a tight after-feel
- Emulsifying: By sitting at the boundary between oil and water it keeps creams, lotions and cleansing milks stable, preventing separation and ensuring a smooth consistent texture throughout the product’s shelf life
Who Can Use Dioleth-8 Phosphate
Dioleth-8 Phosphate is generally well tolerated by all skin types. Dry and sensitive complexions appreciate its mild cleansing action that does not strip the moisture barrier, while oily or combination skin benefits from its ability to lift excess sebum without harsh surfactants. There are no particular concerns for acne-prone skin beyond the usual need to check the full formula of any product.
The ingredient is synthesised from plant-derived oleyl alcohol and contains no animal components so it is suitable for vegans and vegetarians.
Current safety data show no specific risks for pregnant or breastfeeding women when the ingredient is used at the low concentrations found in cosmetics. This is not medical advice and anyone who is pregnant or nursing should run any skincare product by their healthcare provider to be on the safe side.
Dioleth-8 Phosphate is not known to increase photosensitivity and does not make skin more vulnerable to sunburn. It also plays nicely with most common skincare actives such as niacinamide, hyaluronic acid and mild fruit acids.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical application of Dioleth-8 Phosphate can vary from person to person. The points below list potential issues yet they are rare in normal cosmetic use when the ingredient has been formulated correctly.
- Mild skin irritation – a small number of users may notice transient redness or itching, usually if the product contains a high percentage of surfactants overall
- Eye stinging – if a cleanser with this ingredient gets into the eyes it can cause temporary discomfort that subsides after rinsing with water
- Contact dermatitis – very rarely an individual may develop an allergic response leading to localized rash or swelling
If you experience any of the above effects discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
Dioleth-8 Phosphate is highly water-soluble and designed to rinse clean so it is unlikely to linger in pores or form a greasy film. Its structure resembles that of other low-residue cleansing agents which historically score at the lower end of comedogenic scales. Therefore it earns a 1, indicating a very low chance of clogging pores.
The ingredient is generally considered suitable for people who are prone to acne or breakouts.
No published data suggest it interferes with prescription acne treatments or increases follicular occlusion when used at typical cleanser or lotion levels.
Summary
Dioleth-8 Phosphate acts as a gentle cleanser and an emulsifier. Its amphiphilic makeup grabs onto oils and dirt while still dissolving in water, letting formulas lift impurities without stripping skin. At the same time it positions itself between oil and water phases to keep emulsions smooth and stable.
This is not the most famous cosmetic surfactant on the market but it pops up regularly in modern cleansers micellar waters lightweight lotions and a few hair products because it offers mildness and versatility without a big cost premium.
Current research and decades of use show it to be low risk for irritation sensitization or acne. As with any new skincare ingredient it is wise to patch test a product that contains it so you can confirm personal compatibility.