A liquid produced by the distillation of petroleum, mineral oil is odorless, tasteless and inexpensive. It’s a common ingredient in lotions, cold creams, ointments and cosmetics. Recently, there have been studies questioning it’s safety and ability to accumulate and contribute to tumor formation. According to the National Toxicology Program, unrefined or mildly refined mineral oil is a known carcinogen due to the presence of polycyclic aromatic hydrocarbons, which naturally occur in coal and petroleum. PAHs have been linked to various cancers, including scrotal, gastrointestinal, sinonasal, bladder and lung cancer (see source 1 below). Mineral oil used for cosmetic purposes is highly refined to remove PAHs but different manufacturing processes control the quality and purity of the final product. It must be monitored and tested by governmental agencies to ensure safety (see source 4) . Another study in 2009, found that commonly used moisturizing creams containing mineral oil are tumorigenic when applied topically to UVB-pretreated high-risk mice. (see source 2, 3). Consumer advocacy groups suggest caution when using products containing mineral oil until more conclusive research is available.
Sources:
1. http://ntp.niehs.nih.gov/ntp/roc/twelfth/profiles/MineralOils.pdf
3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2630214/?tool=pubmed