Mineral oil is a common ingredient in lip products because it’s highly occlusive, so it locks in moisture. (You can find it in plenty of thick, jelly balms frequently touted for slugging techniques.) The mineral oil used in lip balms is cosmetic-grade and technically safe for skin, as opposed to technical-grade options, which are typically used to lubricate car engines.
That being said, even cosmetic-grade options are still derived from petroleum, “meaning it’s environmentally irresponsible to use mineral oil when there are vegetable and fruit oils, like coconut oil, that are more sustainable,” says clean cosmetic chemist Krupa Koestline about the ingredient. It also does not biodegrade well and can actually accumulate in waterways, which raises even more concern in regards to the health of the environment.
And as we mentioned, mineral oil is highly occlusive, which can create a pore-clogging environment for some. “It more suffocates the skin than anything else,” says board-certified dermatologist Ava Shamban, M.D., founder of SKINFIVE. “The molecular structure is simply too large so it can both clog pores, cause a disruption or even damage to the skin barrier, and ultimately increase transepidermal water loss.” See, you still need some degree of transepidermal water loss for proper skin barrier function, as it signals to your skin cells that it’s time to jump-start repair; if there’s no signaling, your skin cells may think everything is A-OK and won’t repair. Essentially: Preventing transepidermal water loss completely can make your lips feel even drier in the long run.
Given these environmental and skin care concerns, you may be thinking: Why would anyone use mineral oil, anyway? Well, mineral oil can give products a smooth feel when applying, which is appealing to many users. Not to mention they have pretty impressive staying power. Additionally, mineral oil and cosmetic-grade petrochemicals are generally inexpensive, which is appealing to many brands. But as we’ve said before regarding our clean beauty ethos: Just because an ingredient can achieve a desired effect doesn’t mean it supports skin, body, or environmental health long term.