What a 1/5 rating means
On the comedogenic scale, a 1 sits at the safe end of the scale — clogging is unlikely for most people. That places Castor Oil in the range most people, including many with acne-prone skin, tolerate well.
One thing the number cannot tell you is concentration. Ingredients are listed in descending order, so Castor Oil near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Castor Oil
It is a plant- or seed-derived oil, valued for the emollient, conditioning feel it gives a formula. A thick, glossy oil used in cleansing balms and lip products, rated around 1. Its sulfated form (Turkey Red Oil) rates higher.
On a label it can read as Castor Oil, Ricinus Communis Seed Oil — worth knowing when you scan an ingredient deck.
Castor Oil in makeup and skincare
In makeup it turns up in cream blushes, tinted balms, and hydrating foundations; in skincare, in face oils and cleansing balms. Its irritancy is rated separately at 0/5, which is low.
If you deal with fungal acne (malassezia folliculitis) rather than ordinary clogged pores, note that Castor Oil is among the fatty-acid or ester-type ingredients that community sources commonly avoid — a separate concern from its comedogenic score, and one with weaker evidence behind it.