Petroleum jelly is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its healing properties.
After petroleum jelly became a medicine chest staple, consumers began to use it for many ailments, as well as cosmetic purposes, including toenail fungus, genital rashes (non-STD), nosebleeds, diaper rash, and chest colds. Its folkloric medicinal value as a "cure-all" has since been limited by better scientific understanding of appropriate and inappropriate uses. It is recognized by the U.S. Food and Drug Administration (FDA) as an approved over-the-counter (OTC) skin protectant and remains widely used in cosmetic skin care.
Petroleum jelly is a mixture of hydrocarbons, having a melting point usually close to human body temperature, approximately 37 °C (99 °F). It is colorless or has a pale yellow color (when not highly distilled), translucent, and devoid of taste and smell when pure. It does not oxidize on exposure to the air and is not readily acted on by chemical reagents.