Paradichlorobenzene is a hydrocarbon that is aromatic and has been chlorinated. It was registered for use in the United States in 1942. It is used as a fumigant insecticide to control moths from damaging clothes. Another use for paradichlorobenzene is as a deodorant block to be placed in toilets or trash cans. It works well at controlling the growth of mold and mildew. For this reason, it is used to control mold in tobacco seeds. It serves as an intermediate when producing other chemicals, as well. Paradichlorobenzene is a chemical with a vapor that is toxic to insects. This is why it makes a powerful insecticide. Mothballs contain this insecticide, which turns from a solid into a toxic gas to kill the moths. Humans and animals must avoid direct exposure to the chemical, because it can be harmful when the vapor is breathed in, or when you touch the chemical.