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 Caprylic Acid 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 Caprylic Acid near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Caprylic Acid
It is a fatty acid, one of the building blocks of oils and a common texture and cleansing agent. A short C8 fatty acid rated 1/5. Below the malassezia chain-length range, so usually treated as fungal-acne safe.
On a label it can read as Caprylic Acid, Octanoic Acid — worth knowing when you scan an ingredient deck.
Caprylic Acid in makeup and skincare
It shows up in cleansing balms, cream cleansers, and the base of many creams and pressed powders. Its irritancy is rated separately at 3/5, which is worth noting for sensitive or reactive skin.