What a —/5 rating means
Because no dependable rating exists, judge Isononyl Isononanoate by how your own skin responds rather than by a number. The absence of a score is not the same as a zero — it simply means the ingredient has not been reliably tested on the classic comedogenic scale.
About Isononyl Isononanoate
It is a synthetic ester — an oil-and-alcohol reaction product engineered for a smooth, quick-absorbing slip. A light, volatile-feeling branched ester used to replace silicones for a fast, dry finish. Its C9 chains fall below the roughly C11-C24 window malassezia is thought to feed on, so it is not flagged for fungal acne. It is named on the CLEARSTEM pore-clogging ingredient list, but that list does not publish a 0-5 comedogenic score for it and no Fulton-derived table we cite carries one. We therefore leave it unrated rather than invent a number — treat the listing itself as the signal.
On a label it can read as Isononyl Isononanoate, Isononyl Isononoanoate — worth knowing when you scan an ingredient deck.
Isononyl Isononanoate in makeup and skincare
It is a workhorse of foundations, primers, sunscreens, and mascara, where a fast, silky slip sells the texture.