Mineral Oil
Mineral oil (INCI: Paraffinum Liquidum) is a highly refined petroleum-derived liquid consisting of a complex mixture of saturated hydrocarbons with carbon chain lengths predominantly in the C15–C50 range. It is produced by intensive acid treatment, hydrogenation, or a combination of both, followed by additional washing and treating steps. It is a clear, inert, and pure material used in cosmetics for over 100 years. It functions primarily as an emollient and solvent.
Mineral oil is an effective moisturizer that works mainly through occlusivity — sitting on top of the skin to reduce trans-epidermal water loss. It is notably non-irritating and hypoallergenic, making it suitable for very sensitive and allergy-prone skin. A clinical comparison found it equally efficient and safe as extra virgin coconut oil in treating xerosis (very dry skin).
Does not penetrate the skin or deliver biologically active components (e.g., fatty acids, vitamins), so it does not "nourish" the skin the way plant oils do. Industrial-grade mineral oil contains carcinogenic polycyclic compounds, but these are fully removed in cosmetic-grade versions; a 2017 review concluded cosmetic use presents no systemic risk. Some users may dislike its heavy, occlusive feel on skin.
