Naphtha is a flammable liquid made from petroleum (crude oil) or coal tar. It's a mixture of different chemicals that evaporate easily and burn readily, making it useful as fuel and as a starting material for creating plastics, rubber, and other products.

In ancient Persia, people discovered burning pools of naphtha and considered them sacred. Ancient armies sometimes used naphtha as a weapon, pouring it on battlefields and setting it aflame.

Today, naphtha has two main uses: As a solvent (a liquid that dissolves other substances), it helps clean metal parts and remove grease. More importantly, chemical factories use naphtha as a raw material in a process called cracking, where heat breaks its molecules apart to create the building blocks for plastics, synthetic fabrics, and other materials. The plastic in your water bottle, the nylon in backpacks, even some synthetic rubber in tires may have started as naphtha.

You might also encounter naphtha as lighter fluid, the liquid used to help start charcoal grills or campfires. Because naphtha evaporates so easily and catches fire so readily, it must be handled carefully and kept away from sparks or flames.