Mineral oils are frequently used in cosmetic products such as skin creams, lotions, cleansers, etc., on account of their skin tolerance and protecting properties, their high cleansing performance and broad viscosity options.1 Mineral oils and waxes are mixtures of saturated hydrocarbons.1

It has been pointed that there is inconsistency in the current understanding of the dermal penetration of mineral oils following long-term exposure to cosmetic products containing mineral oils and waxes.1

Experimental studies point to the possible carcinogenic effects of aromatic hydrocarbons.2 While hydrocarbons containing 30.2% of aromatic carbon have been shown to have the least dermatogenic effect, those containing 35.2% of aromatic carbon exert higher dermatogenic effect. The highest dermatogenic effect has been noted with samples containing 55.2% of aromatic carbon.2

Light mineral oils applied topically to the skin of experimental models have been shown to cause marked epidermal hypertrophy, hyperplasia, hyperkeratosis, and subsequent depilation.3 Mineral oil has the potential to irritate the skin and cause rash or burning sensation.4

Mineral oil hydrocarbons seem to be the greatest contaminant of the human body. A study explored the sources of mineral oil contamination. In all, 142 women undergoing elective cesarean section were recruited in the study. A specimen of subcutaneous fat was obtained prior to wound closure. On postpartum days 4 and 20, milk samples were collected from the women. Fat and milk samples were assessed for mineral oil saturated hydrocarbons (MOSH). The enrolled women also completed a questionnaire on personal data, nutrition habits, and use of cosmetics. Age was a major predictor for MOSH contamination of fat tissue. Body mass index, country of main residence, number of previous childbirths, use of sun creams in the present pregnancy, and use of hand creams and lipsticks were significant independent determinants. A strong correlation was evident between MOSH concentration in fat tissue and in the corresponding milk fat sample from day 4 and day 20. Increase in MOSH concentration in human fat tissue with age indicated accumulation over time and cosmetics seem to be a key source of the contamination.5

Petrolatum acts as a barrier to lock moisture in the skin in several moisturizers. It is also known as mineral oil jelly. Petrolatum can be contaminated with polycyclic aromatic hydrocarbons (PAHs). Exposure to PAHs has been linked with cancer. PAHs in petrolatum can also cause allergies and skin irritation.6

Thus, it can be deduced that mineral oils have possible carcinogenic effects, cause epidermal hypertrophy, hyperplasia, and hyperkeratosis, and can irritate the skin and cause rashes or burning sensation. Therefore, it seems wise to avoid using mineral oil-based products for skin care.

References

1. Petry T, Bury D, Fautz R, et al. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications. Toxicology Letters 2017;280:70-78.
2. Kimakova T, Poracova J, Dopirakova T, Blascakova M. Mineral Oils and Harmful Effects on Human and Animal Skin. Epidemiology 2011;22(1):S243.
3. Hoekstra WG, Phillips PH. Effects of topically applied mineral oil fractions on the skin of guinea-pigs. Available from: https://core.ac.uk/download/pdf/82433522.pdf.
4. Available from: https://www.nj.gov/health/eoh/rtkweb/documents/fs/1437.pdf.
5. Concin N, Hofstetter G, Plattner B, et al. Evidence for cosmetics as a source of mineral oil contamination in women. J Womens Health (Larchmt). 2011 Nov;20(11):1713-9.
6. Okereke J N, Udebuani A C, Ezeji E U, et al. Possible Health Implications Associated with Cosmetics: A Review. Science Journal of Public Health 2015; 3(5-1): 58-63.