Vaseline Petroleum Jelly Vaseline Vaseline petroleum jelly protects skin from drying elements. Vaseline® Petroleum Jelly is a mixture of mineral oils, paraffin and microcrystalline waxes that, when blended together, create something remarkable - a smooth jelly that has a melting point just above body temperature. The result - it literally melts into skin, flowing into the spaces between cells and the gaps in our lipid barrier. Once there, it re-solidifies, locking itself in place. Vaseline® Petroleum Jelly serves two functions: First it helps keep the outside world out - it protects skin from the effects of weather and exposure. Second, it acts like a sealant to help keep the inside world in - it forms an occlusive barrier to the natural water loss of our skin. So skin that is dry and chapped is protected from drying elements, enabling skin-softening moisture to build up naturally from inside the skin itself.