chemical information


Chemical Class:

Polychlorinated naphthalene (PCN)

Chemical SubClass

Tetrachlorinated naphthalene

Manufacturing/Use Status

use/production has been voluntarily discontinued in the U.S.

Found in these people:

Baby #1, Baby #2, Baby #3, Baby #4, Baby #5, Baby #6, Baby #7, Baby #8, Baby #9, Baby #10, Anonymous Adult 1, Kathy Fowler, U.S. Representative Louise Slaughter

Found in these locations:

Rockville, MD; Upstate New York, NY


There are 75 possible chemical variations of PCNs. They have been used as cable insulation, wood preservatives, engine oil additives, electroplating masking compounds, capacitors, and in dye production (EPA 1983). Products are generally mixtures of several different PCNs. The largest source of PCNs believed to be waste incineration and disposal of items containing PCNs, although other potential sources of PCNs to the environment include sewage discharge from municipal and industrial sites, leaching from hazardous waste sites. PCNs are also unwanted byproducts formed after the chlorination of drinking water (Kuehl et al. 1984b, Vogelgesang 1986, Furlong et al. 1988, Lin et al. 1984, Shiraishi et al. 1985). They have not been used commercially in significant quantities since the 1980s. PCNs are toxic and persistent. They bioaccumulate in people and are stored in fatty tissues. PCNs have not been tested for their ability to induce cancer. The toxic effects of many PCNs are thought to be similar to dioxin. In humans, severe skin reactions (chloracne) and liver disease have both been reported after occupational exposure to PCNs. Other symptoms found in workers include cirrhosis of the liver, irritation of the eyes, fatigue, headache, anaemia, haematuria, impotentia, anorexia, and nausea. At least 10 deaths were reported from liver toxicity. Workers exposed to PCNs also have a slightly higher risk of all cancers combined. (WHO 2001).


PCN-29 has been found in 13 of the 23 people tested in EWG/Commonweal studies.

Top health concerns for PCN-29 (References)

health concern or target organ weight of evidence
Gastrointestinal (including liver)unknown

Results for PCN-29

This chemical was found to co-elute with PCN-27 and PCN-30 and PCN-39 and PCN-28 and PCN-43.

in blood serum (lipid weight)

Showing results from Pollution in Minority Newborns, EWG/Commonweal Study #4, industrial chemicals and pesticides in cord blood, EWG Study #3, industrial chemicals and pesticides in adults

EWG/Commonweal results

  • geometric mean: 0.0206 ng/g (lipid weight) in blood serum
  • found in 13 of 23 people in the group
0 ng/g (lipid weight) in blood serum 0.0664

PCN-29 results

Detailed toxicity classifications (References)

classification governing entity/references
Gastrointestinal system toxicity - weight of evidence unknown/unassessedWard, E. M., Ruder, A.M., Suruda, A. (1994). Cancer mortality patterns among female and male workers employed in a cable manufacturing plant during World War II. J Occup Med 36: 7.