Phenol crystals are used to describe the solid forms that result from the phenol compound, which is also known as the carbolic acid. It is an organic compound that has the molecular structure of C6H5OH. It is an extremely volatile white crystalline solid that is mildly acidic. It requires extremely careful handling because its structure can cause painful chemical burns. Phenol was originally extracted from coal tar, and it is now available on a much larger scale from the extraction of petroleum. It is one of the most commonly used industrial compounds, as it can be applied to a wide range of materials and substances.These crystals and many of their chemical derivatives are used as a key ingredient in build epoxies, detergents, herbicides, and many types of pharmaceutical drugs. Because the compound is so inexpensive to produce and purchase, it is used in a wide variety of niche industries as well.