What Is C12-13 Alketh-1?
C12-13 Alketh-1 is a liquid ingredient made by attaching a small amount of ethylene oxide to synthetic fatty alcohols that have 12 to 13 carbon atoms. Chemists call this process ethoxylation. Because only one unit of ethylene oxide is added on average, the molecule stays light and easy to mix with both water and oil. The fatty alcohols used are produced from petrochemical feedstocks or plant-derived sources, then purified before the ethoxylation step.
The first versions of this ingredient were explored in the mid-20th century when formulators were looking for mild cleansers that could replace harsher soaps. Over time it became a regular feature in rinse-off products because it lifts dirt without stripping the skin’s natural oils. Industry naming rules changed in the 1990s, so what was once listed as C12-13 Pareth-1 is now labeled C12-13 Alketh-1.
You will most often spot C12-13 Alketh-1 in face washes, body washes, shampoos, micellar waters, liquid hand soaps and makeup removers. It can also appear in gentle baby cleansers and exfoliating scrubs where a light foaming touch is needed.
C12-13 Alketh-1’s Cosmetic Benefits/Uses
Formulators choose this ingredient for one main reason
Cleansing: C12-13 Alketh-1 lowers the surface tension of water so oils, makeup and daily grime can be rinsed away more easily. It helps a formula create a soft lather, improves rinse-off and leaves skin or hair feeling clean yet comfortable.
Who Can Use C12-13 Alketh-1
C12-13 Alketh-1 is generally suitable for all skin types including normal, oily, combination and dry skin because it is a mild cleansing agent that removes debris without leaving a tight after-feel. People with very sensitive or compromised skin should still pay attention to how their skin responds since any surfactant can be irritating if used too frequently or at a high concentration.
The ingredient is produced from synthetic or plant-derived fatty alcohols and undergoes no animal-based processing, so it is considered appropriate for vegans and vegetarians.
Available safety data indicate no special concerns for women who are pregnant or breastfeeding when the ingredient is used in rinse-off cosmetics. This is not medical advice and pregnant or nursing women should run any skincare product past a doctor just to be on the safe side.
C12-13 Alketh-1 does not make skin more sensitive to sunlight, so it is not linked to photosensitivity. It also plays well with most other common cosmetic ingredients, letting formulators pair it with actives like salicylic acid, niacinamide and botanical extracts without issue.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical application of C12-13 Alketh-1 can vary from person to person. The following list covers potential issues only and these events are unlikely to be the typical user experience. When used correctly in finished products most people will not notice any negative effects.
- Mild skin irritation – tingling or redness can occur in those with very reactive skin or when the formula is left on too long
– like many cleansers it can cause temporary eye discomfort if the product is not rinsed out promptly - Dryness or tightness – overuse or pairing with other strong surfactants might strip some natural oils especially on already dry skin
- Allergic contact dermatitis – extremely rare but possible if a person is specifically sensitized to this class of ingredients
If you experience any of the above while using a product containing C12-13 Alketh-1 stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
C12-13 Alketh-1 is a lightweight polyethylene glycol ether that prefers to stay dissolved in water rather than sit on the skin’s surface. Because it is used almost exclusively in rinse-off formulas and does not leave behind an oily film, it has little chance of blocking pores. The base fatty alcohols are short-chain enough to stay fluid and get washed away quickly, which further keeps the clogging potential low.
With a rating of 1 it is generally considered suitable for skin that is prone to acne or breakouts.
As with any surfactant, residue left by incomplete rinsing could combine with heavy emollients in the same routine and raise the chance of congestion, but this is easily avoided by thorough rinsing.
Summary
C12-13 Alketh-1 is a mild cleansing agent that lowers surface tension so water can lift away dirt, oil and makeup without stripping the skin or hair. Its small dose of ethylene oxide keeps it water-loving while the 12-13 carbon tail grabs oily grime, giving formulators a balanced surfactant for face washes, shampoos and micellar waters.
The ingredient sits in the mid-tier of popularity: not as famous as sulfates or coco-glucosides but valued by labs that need gentle foam and quick rinse-off.
Safety reviews show a low irritation profile in rinse-off use, no links to sensitization at typical levels and no photosensitivity concerns. Still, individual reactions vary so it is wise to patch test any new product that contains C12-13 Alketh-1 before full-face or full-body use.