White mineral oil, also known as petroleum mineral oil, is a colorless, transparent aerosol liquid that disperses in the air with a smell similar to burnt lubricating oil and has an extremely low odor threshold of only 1.0 ppm. Its Chemical Abstracts Service (CAS) number is 8042-47-5 and it is widely recognized as a cosmetic ingredient, especially when used as a moisturizer. The substance is extracted from petroleum through a multi-step refining process to remove harmful impurities such as sulfur, nitrogen compounds, and heavy hydrocarbons, ensuring its safety and purity. Consisting mainly of hydrocarbons, the molecular structure of white mineral oil gives it excellent lubricity and moisturizing properties, allowing it to form a protective layer on the skin surface to prevent moisture evaporation and keep the skin soft and supple. It is widely used in various cosmetic products such as creams, lotions, baby oil, and sunscreens in the cosmetics industry. Because it does not contain active ingredients, it is less likely to cause skin allergies or irritation and is particularly suitable for sensitive skin. Additionally, its stability and antioxidant properties help prolong the shelf life of cosmetics. However, there is still controversy about the environmental impact and long-term effects on skin health of white mineral oil. Some studies suggest that mineral oil may not be biodegradable and may affect the skin's normal breathing and excretion functions. As a common ingredient in cosmetics, white mineral oil is recognized for its stability and moisturizing effects, but potential environmental and skin effects still need further research. Consumers should make wise decisions based on their skin condition and environmental awareness when choosing and using products containing mineral oil. In laboratory applications, white mineral oil plays a critical role in PCR amplification, reducing evaporation of the reaction liquid in PCR instruments without heating covers to ensure the precision and reliability of the experiment. Additionally, its cleaning and emulsifying properties make it widely used in facial and makeup removal products, effectively removing skin impurities and protecting the skin's natural oil layer. The moisturizing ability of mineral oil has also been widely recognized. It forms a non-polar protective film on the skin surface to prevent moisture evaporation and help maintain skin moisture balance, especially suitable for skin care in dry environments. However, the degree of refinement of mineral oil may affect its effects on the skin, and highly refined mineral oil usually has a lower tendency to clog pores. Despite this, the potential effects of unremoved components in mineral oil, such as polycyclic aromatic hydrocarbons (PAHs), on the skin may be related to skin aging and increased risk of skin cancer. Therefore, consumers should choose mineral oil products that have undergone strict quality control and third-party testing to ensure safety. White mineral oil has important value in scientific experiments and skin care. Its unique properties, such as moisturizing, cleansing, and protective effects, make it a preferred ingredient in many products. However, the use of mineral oil should take into account its refining degree and potential effects to achieve safe and effective application.