para-Dichlorobenzene. Computer model of a molecule of the chlorinated aromatic para-dichlorobenzene (PDB). It is an organic chemical, and is used as a pesticide. It primary use is in mothballs, where it is a substitute for naphthalene (see A705/078). PDB is marketed under names such as Paramoth, Para crystals, and Paracide. It is a toxic substance that can kill through volatile substance abuse. The molecule consists of two chlorine atoms attached to a benzene ring. The molecule's chemical formula is C6.H4.Cl2. The atoms are shown as colour-coded spheres in this ball-and-stick model: carbon (light grey), hydrogen (dark grey), and chlorine (green).