Mineral oil is a type of carrier oil. A carrier oil is any type of oil that helps dilute or solubilize (evenly distribute one ingredient, the solute, into a liquid solvent) another ingredient
Let's explain - have you ever mixed a packet of sugar into a glass of iced tea? Sugar is naturally water-soluble, so all it takes is a few swirls of a spoon and poof! The sugar becomes distributed within the liquid so that it is no longer visible to the naked eye.
The sugar didn't magically disappear into the iced tea. Instead, it became uniformly dispersed, allowing for you to experience the same level of sweetness every time you take a drink . If you had mixed in a sweetener that isn't water soluble, your drink would not be evenly sweet. The particles of the sweetener would sink to the bottom of your tea instead of remaining suspended, and your tea would remain bitter.
While sugar is naturally soluble, other ingredients need some assistance in order to become evenly dispersed in liquid forms, so they don't just sink to the bottom or float on the top. This is where carrier oils, such as cosmetic grade mineral oil, make an enormous difference in cosmetic chemistry. The particles of an insoluble ingredient are able to latch onto those of the carrier oil, and become suspended in the formula instead of sinking to the bottom or floating on the top.
Yes! Mineral oil does not penetrate the hair shaft - its molecular size and functional groups prevent it from "sticking" to proteins, so it easily washed off. The current research indicates that cosmetic grade mineral oil is functionally inert, which means it is extremely unlikely to cause a skin allergy, clog pores, or create any other form of irritation. Although many consumers worry that using products that include cosmetic grade mineral oil will dry out their hair, current scientific literature actually conveys that the opposite of this is true - beyond being an incredibly useful carrying agent, cosmetic grade mineral oil also can help form a protective barrier around the hair to prevent loss of moisture. Hurray for bonus benefits!
This is where there's a lot of confusion. People often point to safety regulations around industrial grade mineral oil to argue that cosmetic grade mineral oil should not be included in cosmetic chemistry. The problem with this argument is that industrial grade mineral oil and cosmetic grade mineral oil are incredibly different in terms of quality. Industrial grade quality mineral oil is full of impurities, whereas cosmetic grade mineral oil is extremely purified and highly regulated.
Here at Formulate, we exclusively use US sourced NF grade mineral oil, which means it has been accepted as a pharmaceutical excipient and manufactured to the standard set by the National Formulary and United States Pharmocopea. We understand the exact manufacturing standards used by our cosmetic grade mineral oil suppliers, and have certified that it is of the very highest quality. Your safety is what matters to us most!
If you ever want to know more about the quality of the mineral oil included in a specific product, the best way to get more information is to ask the company that manufactures it! Don't be afraid to ask for documentation - it's important for companies to be able to not just talk the talk, but walk the walk as well! 😉
The Formulate Team
Rele AS, Mohile RB. Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage. Journal Of Cosmetic Science. 2003;54(2):175-192.
Ruetsch SB, Kamath YK, Rele AS, Mohile RB. Secondary ion mass spectrometric investigation of penetration of coconut and mineral oils into human hair fibers: relevance to hair damage. Journal Of Cosmetic Science. 2001;52(3):169-184.
Keis K, Persaud D, Kamath YK, Rele AS. Investigation of penetration abilities of various oils into human hair fibers. International Journal of Cosmetic Science. 2006;28(1):78. doi:10.1111/j.1467-2494.2006.00304_4.x.
Urlaub J, Norwig J, Schollmayer C, Holzgrabe U. Reply to "Requirements for accurate 1H NMR quantification of mineral oil hydrocarbons (paraffins) for pharmaceutical or cosmetic use." Journal Of Pharmaceutical And Biomedical Analysis. 2019;171:235-237. doi:10.1016/j.jpba.2019.04.020.