What Is C12-13 Pareth-5?
C12-13 Pareth-5 is a group of synthetic fatty alcohols that have been reacted with about five units of ethylene oxide. The numbers C12-13 refer to the length of the carbon chains while Pareth indicates the blend of alcohol and ethylene oxide. The process that links the two parts is called ethoxylation and it turns the raw fatty alcohols, often sourced from plant oils like coconut or palm, into a water-compatible ingredient.
Ethoxylated fatty alcohols first appeared in personal care during the mid-20th century as brands looked for milder alternatives to traditional soaps. Their ability to mix oil and water quickly made them staples in shampoo and body wash research labs and today C12-13 Pareth-5 shows up in a wide range of rinse-off and leave-on products.
Manufacturing starts with splitting natural oils to obtain the C12-13 alcohol fraction. This fraction is purified then fed into a reactor with ethylene oxide gas under controlled heat and pressure. After the fifth mol of ethylene oxide attaches the reaction is stopped and the blend is neutralized and filtered, creating a clear liquid or soft paste.
Because it improves the way water and oil interact you will spot C12-13 Pareth-5 in shampoos, facial cleansers, micellar waters, liquid hand soaps, exfoliating scrubs, light lotions and some sheet mask essences. It is valued for giving formulas a low-foam silky feel and for keeping the mix stable on the shelf.
C12-13 Pareth-5’s Cosmetic Benefits/Uses
Here is what C12-13 Pareth-5 does inside your favorite products:
- Cleansing: The ingredient lowers the surface tension of water so it can lift dirt oil and sweat from skin or hair and rinse them away easily leaving a fresh comfortable finish without harsh stripping
- Emulsifying: It helps water and oil blend into a uniform mixture preventing separation over time which means lotions stay smooth and clear gels keep their body and serums deliver active ingredients evenly with every use
Who Can Use C12-13 Pareth-5
C12-13 Pareth-5 works for most skin types including normal, oily, dry and combination because it is a mild cleansing agent that does not leave a heavy film. People with very sensitive or eczema-prone skin might notice a slight tight feel if the formula is too strong or used too often so they may prefer lower levels or richer follow-up care.
The ingredient itself can be sourced from plant oils which makes it suitable for vegans and vegetarians when a brand chooses plant-based feedstocks. Those who follow a strict lifestyle may want confirmation from the product maker since some suppliers can also use petroleum-derived alcohols.
Current safety reviews show no red flags for use during pregnancy or breastfeeding. Because every situation is unique anyone who is pregnant or nursing should check with a doctor before starting a new cosmetic just to be safe.
C12-13 Pareth-5 does not make skin more sensitive to sunlight and it has no known effect on tanning or pigment.
Potential Side Effects/Adverse Reactions
Responses to topical C12-13 Pareth-5 vary from person to person. The points below cover potential side effects yet most people will not notice any issues when the ingredient is used at the levels found in finished products.
- Mild skin stinging or redness, especially on very delicate or broken skin
- Dry or tight feel after cleansing if the formula has little added moisture
- Temporary eye irritation if the product gets into the eyes
- Rare allergic contact dermatitis marked by itching or small bumps
- Trace amounts of 1,4-dioxane residue from manufacturing can be a concern if a supplier does not use proper purification
If you notice any of these effects stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
C12-13 Pareth-5 is a lightweight water-soluble surfactant that tends to rinse off cleanly so it has very little chance of building up inside pores. It lacks heavy oils or waxes that usually cause clogs which is why its comedogenic score is close to zero yet not quite absolute since any surfactant can leave a trace film if a formula is poorly balanced.
This makes C12-13 Pareth-5 generally fine for people who are prone to acne or frequent breakouts.
Because it appears mostly in wash-off products the short contact time further lowers the risk of pore blockage. If it is blended with rich butters or occlusive silicones in a leave-on product overall comedogenicity will depend more on those other ingredients than on C12-13 Pareth-5 itself.
Summary
C12-13 Pareth-5 cleans and stabilizes formulas at the same time. As a cleanser it lowers water surface tension so oils dirt and sweat slip away easily. As an emulsifier it grabs both water molecules and oily molecules letting them stay mixed so creams stay smooth and gels stay clear.
You will spot it in many mainstream shampoos face washes and micellar waters but it is not a headlining buzzword ingredient so most shoppers never notice it on the label. Lab teams like it because it delivers mild cleansing without heavy foam and keeps costs reasonable.
Safety studies show low irritation risk and almost no long-term concerns. Modern manufacturing removes nearly all unwanted by-products making it a dependable option for daily use. Still every skin is unique so when you pick up a new product that includes C12-13 Pareth-5 it is smart to patch test first to be sure it plays nicely with your skin.