para-Dichlorobenzene (p-DCB)

p-DCB (also known as 1,4-dicholorbenzene or 1,4-DCB) is an organic (has carbon) compond that is used as a disinfectant (mold and mildew control), as a pesticide (moth balls), in deodorant, and as a building block for dyes, pigments, and the polyphenylene sulfide thermal plastic. At room temperature p-DCB vaporizes to produces a distinct "moth-ball" odor.


People are exposed by breathing the vapors or accidently ingesting crystals of p-DCB. Once in the body, p-DCB is metabolized to 2,5-dichlorophenol (2,5-DCP), which is then excreted in urine. The 4CSBC is testing for the 2,5-DCP metabolite to determine the amount of p-DCB people are exposed to.

Exposure Thresholds

Health Concerns

p-DCB is neurotoxic. At high levels of exposure in the air, one experience headache, numbness, weakness of the limbs, and lack of coordiantion (ataxia). High levels of exposure in the air can also cause irritation of the eyes and respiratory tract.

Once p-DCB enters the body, it is metabolized inot other chemicals which may be toxic to other organs, particularly to the liver, thyroid, and pituitary glands.

Maternal exposure to p-DCB may be associated to adverse developmental effects in the mother's unborn baby.

Additional Information

Agency for Toxic Substances and Disease Registry (ATSDR)

Centers for Disease Control and Prevention (CDC)

U.S. Environmental Protection Agency (EPA)

National Pesticide Information Center


Last Update: May 9, 2016