Mineral Oil is a colorless and odorless oil that's made from petroleum- as a by product of the petroleum distillation when producing gasoline. It's long been used as a common ingredient in skincare products, specifically creams, lotions and lip balms in cosmetics and hair products. Commercial baby oil for example is made entirely of mineral oil. Sadly the use of this oil in so many products is not so much for it's healing properties, but rather because it is inexpensive.
Mineral oil acts as a moisturizing agent to the extent that it keeps the area moist. It does not include any important nutrients which are found in other vegetable sourced oils. Jojoba, Avocado, Olive, Plum, Grapefruit oils are some of the oils that offer many nourishing ingredients to the skin.
Mineral oil is said to coat the skin, disrupting the skin's natural immune barrier and thus affecting it's ability to breathe effectively and to absorb natural moisture from the air. It also seems to attract moisture from skin cells , thus causing dehydration, increased collagen breakdown, reduced cellular renewal with the results of premature aging of the skin.
It has also been documented that repeated application to the skin as when applying one's daily moisturizing creams or body lotions, it can have a negative effect on the endocrine system, including ovarian dysfunction, endometriosis, miscarriages and damage to the immune system on the whole.