What it is
C18-21 Alkane is a mixture of branched, saturated hydrocarbons in the C18 to C21 chain-length range, often produced from renewable plant sources as a sustainable alternative to silicones and mineral oil. In formulas it provides a dry, slippery spreadability and a light, non-tacky after-feel, helping disperse pigments and UV filters evenly. It is commonly chosen for clean and natural-positioned products because it delivers a silicone-like sensory without using cyclic silicones.
Safety & warnings
Saturated branched hydrocarbons of this type are generally well tolerated and considered low in irritation and sensitization potential. Because it is a light, spreadable oil it is usually regarded as low on the comedogenicity scale, though individual responses vary.
Origin & sourcing
Often produced from renewable plant feedstocks such as sugarcane-derived or other bio-based sources, though chemically identical branched alkanes can also be petroleum-derived; the CAS reference covers the broader hydrocarbon category.
Questions everyone asks
Is C18-21 Alkane a silicone?
No. It is a branched hydrocarbon oil. It is often used to give a silicone-like silky slip without being a silicone, which appeals to clean-beauty formulations.
Why is it used in sunscreens?
It spreads easily and helps distribute UV filters and pigments evenly while leaving a light, non-greasy feel, improving the overall texture of the product.