What Is Ceteareth-100?
Ceteareth-100 is a nonionic surfactant made by attaching roughly one hundred ethylene oxide units to a blend of cetyl and stearyl alcohols, which come from natural oils such as coconut or palm oil or from petroleum sources. This process, called ethoxylation, turns the waxy fatty alcohols into an ingredient that mixes easily with both water and oil. Chemists first introduced it to personal care formulas in the late 1970s when the industry began looking for gentler alternatives to older detergents. Today it is created in controlled reactors where the fatty alcohols and ethylene oxide combine under heat and pressure then are purified into a fine white pellet or flake. Because it helps oil and water stay blended, you will find Ceteareth-100 in moisturizers, facial masks, body lotions, sunscreens, anti aging creams, hair conditioners, cleansers and makeup removers.
Ceteareth-100’s Cosmetic Benefits/Uses
In daily beauty products Ceteareth-100 performs one key job that makes formulas look and feel better.
Cleansing: As a mild surfactant it lowers the surface tension between dirt or excess oil and your skin so impurities can be lifted away with water. At the same time it keeps oil and water evenly dispersed which gives creams a smooth texture and helps rinse-off products leave less residue.
Who Can Use Ceteareth-100
Ceteareth-100 is generally well tolerated by all skin types including dry, normal, combination and oily skin because it is a gentle surfactant and emulsifier that rinses clean without stripping natural moisture. Very sensitive or reactive skin may still prefer formulas with lower concentrations or extra soothing ingredients if they notice tightness or redness after cleansing.
The ingredient itself is synthetically produced from plant or petroleum sources and contains no animal-derived material, so it is suitable for vegans and vegetarians as long as the finished product is certified cruelty free.
Pregnant and breastfeeding women can usually use products containing Ceteareth-100 without special restrictions, but this is not medical advice and anyone expecting or nursing should review their skincare routine with a qualified healthcare provider to be safe.
Ceteareth-100 does not increase photosensitivity, so there is no added risk of sunburn beyond normal daily exposure. It is also odorless and non-volatile, so it will not interfere with fragranced products or essential oils in a routine.
Potential Side Effects/Adverse Reactions
Reactions to topical Ceteareth-100 differ from person to person. The points below outline potential side effects, though most users will not experience them when the ingredient is properly formulated and used at recommended levels.
- Mild skin irritation such as redness stinging or itching, more likely on compromised or very sensitive skin
- Contact dermatitis in rare cases for individuals allergic to ethoxylated compounds
- Eye irritation if the product accidentally gets into the eyes before rinsing
- Follicular buildup leading to a heavy feel on hair or skin when used in high amounts or not rinsed thoroughly
If any of these effects occur discontinue use and consult a healthcare professional
Comedogenic Rating
Comedogenic rating: 2 out of 5
Ceteareth-100 comes from fatty alcohols but the lengthy ethoxylation process makes it more water friendly and less likely to block pores than its raw counterparts. It tends to stay near the skin surface and then wash away, so only a mild risk of congestion remains, mainly in rich leave-on creams used on very oily skin.
Most acne-prone users tolerate it well, especially in rinse-off cleansers or when it appears low on the ingredient list.
Pairing it with light emollients and thorough rinsing further keeps buildup in check, which is why formulators often rely on it without seeing widespread breakout complaints.
Summary
Ceteareth-100 acts as both a gentle cleanser and an emulsifier, breaking the bond between grime and skin while helping water and oil blend into smooth stable mixtures. This dual role lets products spread easily, feel silky and rinse clean.
Its reliability has made it a workhorse in everyday lotions, sunscreens, masks and conditioners, even as newer plant-based options enter the market.
Regulatory reviews consider it low risk for irritation or toxicity at normal use levels, so most people can use it confidently. Still, every complexion is unique, so doing a quick patch test when you try a product with Ceteareth-100 is a smart habit.