What Is Sodium Undeceth-5 Carboxylate?
Sodium Undeceth-5 Carboxylate is a synthetic surfactant made by linking a plant or petroleum derived C11 fatty alcohol to roughly four units of ethylene oxide, then adding a carboxyl group and neutralizing it with sodium hydroxide. The result is a mild anionic compound that dissolves well in water and helps oil and water mix. Chemists began using ethoxylated carboxylate surfactants in the late 1980s as they searched for gentler cleansers that still produced a satisfying lather. Today this ingredient appears in many rinse off formulas including shampoos, facial cleansers, body washes, baby washes, micellar waters, refreshing toners, bath foams and makeup removers. It is usually blended with other surfactants to balance foam, thickness and skin feel.
Sodium Undeceth-5 Carboxylate’s Cosmetic Benefits/Uses
Formulators include Sodium Undeceth-5 Carboxylate to improve the way a product cleans and feels on the skin or hair.
- Cleansing – lowers the surface tension of water so dirt oil and product buildup lift away easily then rinse off without residue which leaves skin and hair feeling fresh and soft
- Emulsifying – keeps water based and oil based ingredients uniformly mixed so the formula stays stable looks appealing and delivers an even dose of actives with every use
Who Can Use Sodium Undeceth-5 Carboxylate
This gentle anionic surfactant is generally well tolerated by all skin types including dry sensitive oily and combination because it cleans without stripping too much of the skin’s natural moisture. People with extremely sensitive or compromised skin should still pay attention to overall formula strength since very high surfactant levels can feel drying.
The compound is synthesized from plant or petroleum feedstocks with no animal derived components so it is suitable for vegans and vegetarians. Cruelty free status depends on the finished brand’s animal testing policies rather than the ingredient itself.
Pregnant or breastfeeding women are not expected to face special risks from normal topical use as the ingredient stays on the outer skin layers and is rinsed away. This is not medical advice and anyone who is pregnant or nursing should show any skincare product they plan to use to a qualified health professional just to be safe.
Sodium Undeceth-5 Carboxylate does not increase photosensitivity so it will not make skin more prone to sunburn. It is also considered safe for use on the scalp and hair including color treated hair when used at normal wash off levels.
Potential Side Effects/Adverse Reactions
Individual responses can differ and the following is a list of potential effects that could occur even though most users will not experience them if the finished product is formulated correctly.
- Mild eye irritation brief stinging or tearing if the cleanser accidentally gets into the eyes
- Temporary skin tightness or dryness if the overall formula contains a high total surfactant load or if used too frequently
- Contact dermatitis rare cases of redness itching or rash in people with specific sensitivities to ethoxylated surfactants
- Scalp irritation itching or flaking when used in concentrated shampoos on very sensitive scalps
If any discomfort or visible reaction develops stop using the product and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0–1 (effectively non-comedogenic)
Sodium Undeceth-5 Carboxylate is a lightweight water-soluble surfactant that rinses off cleanly and does not leave a film that could block pores. It lacks heavy oils or waxes and has no known tendency to promote blackheads or whiteheads in clinical or anecdotal reports. Because it usually appears in rinse-off products its brief contact time further lowers any pore-clogging risk.
Suitable for acne-prone skin since it is unlikely to aggravate breakouts.
As with any cleanser the finished formula’s total surfactant blend and added emollients ultimately determine pore impact so very rich creamy washes that also contain occlusive ingredients could still pose a risk even if this specific surfactant does not.
Summary
Sodium Undeceth-5 Carboxylate is a synthetic anionic surfactant that lifts away dirt oil and product residue while keeping water and oil ingredients evenly mixed. It achieves these tasks by lowering the surface tension of water and providing a stable interface between oily and watery phases so every pump or splash delivers consistent performance.
Although not as famous as sulfate surfactants or trendy sugar-based cleaners it has carved out a steady niche in gentle shampoos micellar waters and baby washes where formulators want mildness plus decent foam.
Current safety assessments find it non-sensitizing and non-toxic at the low percentages used in rinse-off products. Still everyone’s skin is different so patch testing a new product that contains this ingredient is a smart precaution.