Tridecane
Hydrocarbon with 13 carbons. Used as a light volatile emollient, often paired with Undecane in the Cetiol Ultimate system. Gives a 'dry' spread and evaporates after application. An alternative to cyclic silicones. Main use – sunscreens and lightweight serums.
Supporting ingredient
It gives a product its texture, stability or shelf life. It has no claimed effect on the skin, so an efficacy tier does not apply. What is known about its safety is below
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Combination, Oily
- Use with caution
- Sensitive
About this ingredient
Tridecane is a linear hydrocarbon with 13 carbon atoms. Mostly produced synthetically from plant feedstock (BASF Cetiol Ultimate). Liquid, odourless, leaves no greasy residue. Mechanism. Lightweight volatile emollient. Smooths the skin by filling intercorneocyte spaces; evaporates within 10-30 minutes. Does not occlude the skin or block TEWL like an occlusive, hence the 'dry' texture feel. Fully compatible with UV filters and silicones. Where applied. Sunscreens (especially light lotions and sprays), primers, light serums, products for oily and combination skin. Paired with undecane it forms the Cetiol Ultimate system (BASF) – a popular replacement for cyclic silicones (cyclopentasiloxane) after EU restrictions on D4/D5. In Spain it shows up in Heliocare, Isdin and La Roche-Posay Anthelios sunscreens. Evidence base. Volatile emollients are functional ingredients: they don't treat skin but improve spread and sensorial feel. Cetiol Ultimate (tridecane + undecane) in BASF studies reduces stickiness in sunscreens and improves UV-filter film spread on skin. Safety. CIR assessed alkanes C7-C16 as safe in 2018. Non-sensitising, non-comedogenic (rating 0). Pregnancy and lactation – safe. Usable in sunscreens and creams without restrictions.
Frequently asked questions
Is Tridecane safe during pregnancy?
Tridecane is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Tridecane for?
Tridecane suits: normal, combination, oily. Use with caution in: sensitive.
What is Tridecane and what does it do in cosmetics?
Hydrocarbon with 13 carbons.
Is Tridecane comedogenic?
On the Fulton scale 0/5 – non-comedogenic. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
What's the INCI name for Tridecane?
The INCI name is Tridecane. It may also appear as: n-Tridecane, C13 isoalkane.
See Tridecane in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Similar role in the formula
Other functional ingredients
Trideceth-10, Trideceth-6, Trideceth-9, Triethanolamine, Ceresin, Helianthus Annuus Seed Cera, PEG-20 Glyceryl Triisostearate, PVP
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