Petrolatum, also known as petroleum jelly, is a semisolid mixture of hydrocarbons obtained from petroleum refining. It has a melting point close to body temperature, which allows it to soften upon application and form a water-repellent film around the applied area, creating an effective barrier against the evaporation of the skin’s natural moisture and foreign particles or microorganisms that may cause infection. Petrolatum is odorless and colorless, and it has an inherently long shelf life, making it a popular ingredient in skincare products and cosmetics. It is classified as an occlusive moisturizer, which means it works by creating a physical, water-resistant barrier on top of the skin, sealing in moisture and helping to prevent transepidermal water loss. When properly refined, petrolatum has no known health concerns. However, petrolatum is often not fully refined in the US, which means it can be contaminated with toxic chemicals called polycyclic aromatic hydrocarbons (PAHs) . PAHs are byproducts of organic material combustion, commonly stored in fats upon exposure due to its lipophilic properties. Exposure to PAHs, including skin contact over extended periods of time, is associated with cancer. The European Union classifies petrolatum as a carcinogen and restricts its use in cosmetics. In the US, there is no parallel restriction, but petrolatum has been flagged for future assessment under the government’s Chemicals Management Plan.