What Is Nonyl Nonoxynol-11 Phosphate?
Nonyl Nonoxynol-11 Phosphate is a synthetic ingredient made by linking nonylphenol with ethylene oxide units and then adding a phosphate group. On paper its chemical name looks long, but in practice it is simply a surfactant with an average of 11 repeating ethylene oxide units. Manufacturers first explored this class of materials in the mid-20th century while searching for milder alternatives to soap that could break down oils without irritating skin. By the 1980s formulators discovered that adding a phosphate group improved the ingredient’s ability to work in a wider range of pH levels, making it more versatile in personal care products.
The production process starts with nonylphenol, a compound derived from petroleum. Ethylene oxide gas is then reacted with the nonylphenol to build the chain of 11 oxyethylene units. Finally the resulting nonylphenol ethoxylate is treated with phosphoric acid to create the phosphate salt that is used in cosmetics. Each of these steps happens in closed reactors to control heat and pressure and to ensure purity.
Because of its surface-active properties, Nonyl Nonoxynol-11 Phosphate shows up most often in cleansers, makeup removers, shampoos, body washes and exfoliating masks. It can also be found in some micellar waters and pre-shave products where a mild yet effective cleanser is required. Formulators appreciate that it rinses away easily and can help stabilize emulsions, so it sometimes appears in lightweight moisturizers and leave-on lotions as well.
Nonyl Nonoxynol-11 Phosphate’s Cosmetic Benefits/Uses
This ingredient plays a straightforward but important role in many personal care formulas.
Cleansing: As a surfactant it lowers the surface tension between water and oil, allowing dirt, makeup and excess sebum to lift away from skin or hair. Its phosphate group helps it work even when the product contains acidic or basic ingredients, so cleansers maintain their performance throughout their shelf life. Users get a thorough yet gentle clean without the tight or stripped feeling that harsher detergents can leave behind.
Who Can Use Nonyl Nonoxynol-11 Phosphate
Thanks to its mild cleansing profile Nonyl Nonoxynol-11 Phosphate is generally suitable for normal, dry, oily, combination and sensitive skin. People with a history of reacting to surfactants or nonylphenol derivatives should proceed with extra caution because even gentle cleansers can occasionally provoke redness or itchiness in highly reactive skin.
The ingredient is synthetically produced from petroleum based raw materials so it contains no animal derived components, making it appropriate for vegans and vegetarians. Individual brands may still differ in their animal testing policies so anyone strictly following cruelty-free guidelines should verify the finished product’s certification.
No specific warnings exist for pregnant or breastfeeding women when this ingredient is used at the concentrations common in rinse-off or leave-on cosmetics. That said this is not medical advice and expectant or nursing mothers should review any skincare product with their physician before adding it to a routine.
Nonyl Nonoxynol-11 Phosphate does not absorb UV light and is not known to increase photosensitivity. It also plays well with other actives like acids and retinoids because its phosphate group keeps it stable across a broad pH range.
Potential Side Effects/Adverse Reactions
Responses to topical Nonyl Nonoxynol-11 Phosphate vary from person to person. The following list covers potential side effects, though most users will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild skin irritation such as redness, tingling or itchiness
- Drying or tight feeling if the surrounding formula lacks adequate moisturizers
- Allergic contact dermatitis in individuals sensitized to nonylphenol ethoxylates
- Eye stinging or watering if the cleanser accidentally gets into the eyes
- Exacerbation of pre-existing eczema or barrier damage when used too frequently
If you notice any of these reactions discontinue use immediately and seek guidance from a qualified healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5
Nonyl Nonoxynol-11 Phosphate is a water-soluble surfactant that rinses off cleanly and does not leave behind oily residues that clog pores. Its molecular size and polar phosphate group further limit buildup on the skin, keeping the chance of blocked pores low. For these reasons it earns a score of 1 which means it is very unlikely to trigger comedones in most users. People who are prone to acne or breakouts can generally use products containing this ingredient without added worry.
The actual risk also depends on the full formula. If the product pairs this surfactant with heavy oils or waxes, overall pore-clogging potential could rise, so always consider the full ingredient list.
Summary
Nonyl Nonoxynol-11 Phosphate is mainly a cleansing agent. As a surfactant it lowers surface tension so water can mix with oil and dirt, lifting grime away from skin or hair. The added phosphate group lets it stay active over a wide pH range which helps formulas stay stable and effective.
This ingredient is not a household name yet it has a steady spot in gentle cleansers, micellar waters and some lightweight lotions thanks to its mild nature and easy rinse-off profile.
Current safety data show low irritation and very low comedogenicity at the levels used in cosmetics. Even so skin is personal so it is smart to patch test any new product that features Nonyl Nonoxynol-11 Phosphate before full use.