Petroleum Jelly / White Petroleum Jelly, petrolatum or soft paraffin, is a semi-solid mixture of hydrocarbons, originally promoted as a topical ointment for its healing properties. Petroleum jelly is a flammable, semi-solid mixture of hydrocarbons, having a melting-point usually within a few degrees of 75°C. It is colorless, or of a pale yellow color , translucent, and devoid of taste and smell when pure. White petroleum jelly is a non-polar hydrocarbon hydrophobic and insoluble in water, glycerol (not a hydrocarbon but an alcohol) is the opposite: petroleum jelly is so strongly hydrophilic that by continuous absorption of moisture from the air, it produces the feeling of wetness on the skin, similar to the greasiness produced by petroleum jelly. The feeling is similar, but white petroleum jelly repels water, and glycerine attracts it.