What Is Ammonium Trideceth-6 Phosphate?
Ammonium Trideceth-6 Phosphate is a surfactant made by joining tridecyl alcohol, ethylene oxide and phosphoric acid, then neutralizing the mix with ammonia. The result is an ammonium salt that carries both water loving and oil loving parts, which is why it works so well in cleansing and mixing tasks. The ingredient first appeared in personal care formulas in the late 1990s when brands were looking for milder alternatives to older sulfate surfactants. Because it is less likely to strip skin or hair, formulators adopted it for everyday products.
Production starts with tridecyl alcohol, usually sourced from plant or petrochemical feedstocks. This alcohol reacts with ethylene oxide in a controlled process to add six repeating units, creating Trideceth-6. Phosphoric acid is then added to convert part of the molecule into a phosphate ester. Finally the mixture is treated with ammonia to form the ammonium salt, improving solubility in water-based products.
You will most often see Ammonium Trideceth-6 Phosphate in facial cleansers, body washes, shampoos, makeup removers, micellar waters and sometimes in lightweight lotions where it helps oils and water stay blended. It may also pop up in exfoliating masks or wipes that need gentle yet effective cleansing power.
Ammonium Trideceth-6 Phosphate’s Cosmetic Benefits/Uses
This ingredient serves two key roles in cosmetics
- Cleansing: Its surfactant nature lifts away dirt, oil and product buildup without creating harshness, leaving skin or hair feeling fresh and soft
- Emulsifying: It helps oil and water mix smoothly, giving products a stable, even texture so the formula stays uniform from the first use to the last
Who Can Use Ammonium Trideceth-6 Phosphate
Because it is a mild surfactant, Ammonium Trideceth-6 Phosphate is generally well tolerated by most skin types, including oily, combination, normal and dry skin. People with very sensitive or compromised skin should still monitor how their skin feels, as even gentle cleansers can sometimes cause dryness if overused.
The ingredient is typically synthesized from plant or petrochemical sources with no animal-derived inputs, so products featuring it are usually suitable for vegans and vegetarians. Always check the full ingredient list to confirm no other animal ingredients are present.
No data suggest any special risks for women who are pregnant or breastfeeding when the ingredient is used topically in rinse-off or leave-on cosmetics. This is not medical advice; expectant or nursing mothers should discuss any skincare product with their healthcare provider to be safe.
Ammonium Trideceth-6 Phosphate does not increase photosensitivity, so it will not make skin more prone to sunburn. Standard daily sun protection is still recommended as part of a healthy routine.
Potential Side Effects/Adverse Reactions
Reactions to topical Ammonium Trideceth-6 Phosphate vary from person to person. The following is a list of potential side effects that could occur, although most users will not experience them when the ingredient is properly formulated and used as directed.
- Mild skin dryness
- Temporary tightness or squeaky feel after rinsing
- Minor eye irritation if product accidentally gets into the eyes
- Rare cases of redness or itching in very sensitive individuals
If you notice any discomfort or irritation while using a product that contains this ingredient stop use and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 1/5
Ammonium Trideceth-6 Phosphate is highly water-soluble and designed to rinse away rather than sit on the skin. Its molecules are large enough to stay on the surface and lift off oils yet small enough to wash off cleanly, so it rarely blocks pores. A rating of 1 reflects this low likelihood of clogging while still acknowledging that any surfactant could cause trouble for a very small group of users.
Because of its low rating it is generally fine for people who break out easily, especially in rinse-off products like cleansers and shampoos.
No special interactions with other pore-clogging ingredients are known, but a heavy formula packed with oils or butters can still cause congestion even if this surfactant is present.
Summary
Ammonium Trideceth-6 Phosphate mainly cleans and emulsifies. Its split personality molecule has an oil-loving tail that grabs grime plus a water-loving head that lets grime rinse away, leaving skin or hair refreshed without harshness. In emulsions the same structure keeps water and oil blended so lotions and creams stay smooth and stable.
It is not a headline ingredient like hyaluronic acid and vitamin C, but brands that focus on gentle everyday cleansing often pick it over stronger sulfates. You will notice it most in facial cleansers, body washes, micellar waters and lightweight lotions.
Current research shows it is low risk for irritation, non-sensitizing and rated low on the comedogenic scale, making it safe for most users when used as directed. Still, everyone’s skin is different so perform a simple patch test when trying a new product that contains this ingredient just to be sure your skin agrees with it.