Phenol is a derivative of benzene, having the following structure:

It is a white/transparent solid with a very strong penetrating odor. In the past it was used for disinfecting purposes and older people among us certainly will recognize its odor and associate that with antiseptics.

Phenol has a low melting point of 40.5 °C but small amount of moisture sharply decrease the melting point and for this reason many samples of phenol have a somewhat wet appearance. Phenol must be protected from air, because it is slowly oxidized when in contact with air and then it becomes red/brown. A pure sample is white or transparent.