The main raw material of candles is paraffin (C₂₅H₅₂), which is obtained from the waxy fraction of petroleum by cold pressing or solvent dewaxing. Octadecane (C28H58), containing about 85% carbon and 14% hydrogen. The added accessories are white oil, stearic acid, polyethylene, essence, etc. Among them, stearic acid (C17H35COOH) is mainly used to improve the softness, and the specific addition depends on what kind of candles are produced.
It is easy to melt, and its density is less than that of water and it is difficult to dissolve in water. When heated, it melts into a liquid state, colorless and transparent, and volatile when slightly heated, and can smell the unique odor of paraffin. When cold, it solidifies into a white solid with a slight special odor.