Trideceth-9
What Trideceth-9 is & what it does
Trideceth-9 is a synthetic nonionic surfactant made by reacting a branched C13 fatty alcohol (tridecyl alcohol) with about 9 units of ethylene oxide. In sunscreens and other skincare formulas it works as an emulsifier and solubilizer, helping oils, fragrances, and UV filters disperse evenly in water-based systems. The number 9 refers to its average degree of ethoxylation, which makes it relatively water-soluble.
What does Trideceth-9 do in skincare?
Trideceth-9 works as an emulsifier and solubilizer. It helps oils, fragrances, and UV filters mix evenly into water-based formulas, which keeps sunscreens and lotions smooth and stable. It is a nonionic surfactant, so it is generally mild in this role.
Is Trideceth-9 natural or synthetic?
Trideceth-9 is synthetic. It is made by reacting a fatty alcohol with ethylene oxide, a process called ethoxylation. The 9 indicates the average number of ethylene oxide units attached.
Is Trideceth-9 safe?
Trideceth-9 is widely used as a cosmetic emulsifier and solubilizer and is generally considered safe for use in rinse-off and leave-on products at standard levels. As with other ethoxylated ingredients, reputable manufacturers purify it to limit trace impurities. If you have specific concerns, check with a qualified professional.
Sunscreens with Trideceth-9
We rate 12 sunscreens that contain it, showing the top 10 by overall score:
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Wardah UV Shield Tone Up Sunscreen Serum SPF 50 Pa+++
79/100
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Nivea Daily Protection Sun Lotion SPF 33 Pa +++
72/100
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Emina Water UV Gel SPF 50 Pa++++
72/100
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BABE Fotoprotector Facial Oil-Free Sun Cream Spf50
70/100
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Nivea Extra Whitening Cell Repair Spf 15 Body
67/100
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Nivea Extra Whitening Cell Repair And Uv Protect Body Lotion Spf 15
67/100
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Nivea Natural Glow Cell Repair SPF 15
66/100
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Nivea Daily Protection Sun Lotion SPF 33 PA +++ (New)
65/100
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Wardah Crystallure Supreme Revitalizing Rich Cream 35 Pa+++
64/100
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Maria Ross Paris SPF 40
49/100