What Is Aluminum Dicetyl Phosphate?
Aluminum dicetyl phosphate is the aluminum salt of dicetyl phosphate, a compound made when phosphoric acid reacts with two molecules of cetyl alcohol, a fatty alcohol often sourced from plant oils. Once this fatty phosphate is formed it is neutralized with an aluminum compound, giving a fine white powder that blends easily with both oils and water. The ingredient was introduced in the 1970s as chemists looked for more reliable ways to keep water and oil phases from separating in creams and makeup.
Today manufacturers produce aluminum dicetyl phosphate in large reactors where cetyl alcohol and phosphoric acid are heated under controlled conditions. After the reaction is complete aluminum hydroxide or a similar aluminum source is added, then the mixture is washed, dried and milled. The finished material is lightweight, disperses quickly and has a low odor, making it convenient for use in personal care labs.
You will most often spot aluminum dicetyl phosphate in products that need long term stability such as fluid foundations, tinted moisturizers, sunscreens, BB and CC creams, anti aging lotions, overnight masks, leave on hair conditioners and some cream based color products like blush or high coverage concealer. It is also common in water resistant formulas where keeping oily and watery parts together is critical.
Aluminum Dicetyl Phosphate’s Cosmetic Benefits/Uses
This ingredient mainly acts as an emulsion stabilising agent. By lodging itself at the border between the water phase and the oil phase it strengthens the bond between the two. The result is a cream or lotion that stays smooth, does not split in the jar and feels uniform on the skin. A stable emulsion spreads more evenly, holds pigments in place for better color payoff and can tolerate temperature swings during shipping and storage, all of which translate to a longer shelf life and consistent performance for the consumer.
Who Can Use Aluminum Dicetyl Phosphate
Aluminum dicetyl phosphate is considered suitable for most skin types including dry, normal, combination and oily skin because it sits on the surface and does not significantly alter the skin’s moisture balance. Sensitive skin generally tolerates it as well but anyone with a known sensitivity to aluminum salts or fatty alcohol derivatives may prefer to avoid it.
The cetyl alcohol used to make this ingredient is typically sourced from plant oils such as coconut or palm so finished material is usually vegan and vegetarian friendly. That said some suppliers may still offer grades derived from animal fats so strict vegans should check with the brand for sourcing details.
No evidence suggests that aluminum dicetyl phosphate is harmful during pregnancy or while breastfeeding when used topically in cosmetic amounts. This is not medical advice and anyone who is pregnant or nursing should show the full ingredient list of their products to a qualified healthcare professional before use just to be safe.
The ingredient is not known to cause photosensitivity so it will not make skin more prone to sunburn. It also has no impact on hair color treatments or common actives like retinol or vitamin C so it can be layered without special precautions.
Potential Side Effects/Adverse Reactions
Side effects from topical use of aluminum dicetyl phosphate can vary from person to person. The points below reflect potential reactions that could occur even though they are unlikely for the average user when the ingredient is formulated correctly.
- Mild skin irritation such as redness itching or a stinging sensation
- Allergic contact dermatitis in individuals sensitive to aluminum compounds or fatty alcohol derivatives
- Follicular clogging in very acne prone skin if used in a heavy or occlusive formula
- Eye irritation if loose powder gets into the eyes during product application
If you experience any of these reactions stop using the product and seek advice from a medical professional or dermatologist.
Comedogenic Rating
Aluminum dicetyl phosphate carries a comedogenic rating of 1 on the 0-5 scale. The molecule is a lightweight salt that stays mostly at the surface, offers little occlusion and is used at low percentages, so it is unlikely to block pores in most formulas. Those prone to acne or breakouts generally tolerate it well, though very heavy creams packed with multiple fatty ingredients could still pose a risk if your skin clogs easily. Because it is an inorganic salt rather than a pure fatty acid, it does not feed acne-causing bacteria the way richer oils sometimes can.
Summary
Aluminum dicetyl phosphate is best known for keeping oil and water phases locked together, making lotions, creams and makeup stay smooth from the lab bench to your bathroom shelf. It wedges itself at the interface of oils and water, forming a thin film that stabilizes the entire emulsion so pigments stay suspended, textures remain silky and products resist temperature swings.
While not a headline ingredient it remains a quiet workhorse in many foundations, sunscreens and skin care creams where reliable stability is a must. Brands choose it because it is easy to disperse, has virtually no scent and does not interfere with color or active ingredients.
Safety data show the salt is non irritating for most users with a low risk of sensitization. Still every skin type is unique, so it is smart to patch test any new product that includes aluminum dicetyl phosphate before committing to full-face or full-body use.