UK blogger, Scientist, Dr. Ruby Majani aka JC of The Natural Hair Haven - Science and Natural Hair blog listed the following facts about mineral oil.
It is from fossil fuel and therefore considered natural in origin. All oils (including coconut, castor or mineral oil) form a barrier on the hair delaying water entry or exit to the hair. No oil can fully prevent water entry or exit.
Mineral oil is useful when hair needs to be kept dry. For example, for straight styling or styling in high humidity.
She stated that mineral oil forms one of the best barriers as far as oils go, therefore if hair is damaged or prone to being dry then it should be used sparingly.
For those that know from experience that mineral oil and their hair don’t get along, there are alternatives. Vegetable oils or butters are great substitutes for mineral oil/petroleum jelly.
Jojoba, Grapeseed, Sweet Almond, Avocado, Broccoli Seed, Calendula are examples of oils that can be used instead of mineral oil.
Also, for those who are more daring and don’t have a problem with using beeswax, you can make your own petroleum-free jelly with beeswax.
2 ounces olive oil
1/2 ounce grated beeswax
12 drops grapefruit seed extract
1. In a double boiler over simmering water and medium heat, combine the olive oil and beeswax, and heat until the wax has melted.
2. Remove mixture from the heat and add the grapefruit seed extract.
3. Beat with a hand mixer until creamy.
Makes 1/4 cup. Store in a glass jar with a screw-top. This jelly will keep for a year.
For those who prefer not to use beeswax, you can use vegetable wax or jojoba wax as substitutes.