Clear, odorless oil derived from petroleum that is widely used in cosmetics because it rarely causes allergic reactions and it cannot become a solid and clog pores. Despite mineral oil’s association with petroleum and the hype that it is bad for or ages skin, keep in mind that petroleum is a natural ingredient derived from the earth and that once it becomes mineral oil USP (cosmetics- and pharmaceutical-grade mineral oil), it has no resemblance to the original petroleum.
Cosmetics-grade mineral oil and petrolatum are considered the safest, most nonirritating moisturizing ingredients ever found (Sources: Cosmetics & Toiletries, January 2001, page 79; and Cosmetic Dermatology, September 2000, pages 44–46). Yes, they can keep air off the skin to some extent, but that’s what a good antioxidant is supposed to do; they don’t suffocate skin! Moreover, mineral oil and petrolatum are known to be efficacious in wound healing, and are also among the most effective moisturizing ingredients available (Source: Cosmetics & Toiletries, February 1998, pages 33–40).
Mineral oil is not an ingredient to avoid unless you have oily skin, in which case the somewhat greasy texture of mineral oil won't feel the best (but again, mineral oil doesn't clog pores or suffocate skin).
The confusion around mineral oil is also caused by some cosmetics companies and people who use the information about non-purified mineral oil as a scare tactic. The mineral oil used in skin-care products is certified as either USP (United States Pharmacopeia) or BP (British Pharmacopeia). This is the type that’s used in skin-care products, and it’s completely safe, soothing, non-irritating, and perfectly healthy for skin (Sources: Sources: Journal of Dermatologic Science, May 2008, pages 135–142; International Journal of Cosmetic Science, October 2007, pages 385–390; European Journal of Opthalmology, March-April 2007, pages 151–159; International Wound Journal, September 2006, pages 181–187; Ostomy Wound Management, December 2005, pages 30–42; and Dermatitis, September 2004, pages 109–116).