<< Back to Chemical Sampling Information

Chemical Sampling Information (CSI)
Search (use word(s)/phrase)
Table of Contents
By Name

By CAS Number
Quick Links

General Description

Synonyms: Dichlorobenzene; 1,4-Dichlorobenzene; p-DCB; para-Dichlorobenzene; Dichlorocide

OSHA IMIS Code Number: 0868

Chemical Abstracts Service (CAS) Registry Number: 106-46-7

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: CZ4550000

NIOSH Pocket Guide to Chemical Hazards, p-Dichlorobenzene: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Table Z-1 -- 75 ppm, 450 mg/m3 TWA

Construction Industry: 29 CFR 1926.55 Appendix A -- 75 ppm, 450 mg/m3 TWA

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 75 ppm, 450 mg/m3 TWA

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 10 ppm, 60 mg/m3 TWA; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

Carcinogenic Classification:

International Agency for Research on Cancer (IARC): Group 2B, Possibly Carcinogenic to Humans [134 KB PDF, 54 pages]

National Toxicology Program (NTP): Group 2, Reasonably Anticipated to be Human Carcinogen
[186 KB PDF, 3 pages]

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 150 ppm

Potential Symptoms: Eye irritation, periorbital swelling; profuse rhinitis; headache, anorexia, nausea, vomiting; weight loss; hemolytic anemia; jaundice, cirrhosis; burning sensation; drowsiness; cough, shortness of breath; In animals: liver, kidney damage; INGES. ACUTE: diarrhea; [potential occupational carcinogen]

Health Effects: Cumulative systemic toxicity (HE3); Cataracts (Limited evidence) (HE7)

Affected Organs: Liver, respiratory system, eyes, kidneys, skin


  1. p-Dichlorobenzene is an OSHA Select carcinogen.
  2. It is metabolized primarily in the liver by cytochrome P450 2E1 to the urinary metabolite 2,5-dichlorophenol, which is excreted both free and conjugated.
  3. Chloracne was reported in nine long-term male workers in a factory producing chlorobenzene chemicals, including p-dichlorobenzene. All nine also had a mixed polyneuropathy.
  4. One case of neuropathy (ataxia, dysarthria, limb weakness, hyporeflexia) due to chronic overuse of a moth repellant p-dichlorobenzene product at home has been reported.

Literature Basis:

  • NIOSH Pocket Guide to Chemical Hazards: p-Dichlorobenzene.
  • International Chemical Safety Cards (WHO/IPCS/ILO): 1,4-Dichlorobenzene.
  • Bogaards, J.J.P., van Ommen., B., Wolf, C.R. and van Bladeren, P.J.: Human cytochrome P450 enzyme selectivities in the oxidation of chlorinated benzenes. Toxicol. Appl. Pharmacol. 132(1): 44-52, 1995.
  • Miyai, I., Hirono, N., Fujita, M. and Kameyama, M.: Reversible ataxia following chronic exposure to paradichlorobenzene. J. Neurol. Neurosurg. Psychiatry 51(3): 453-454, 1988.
  • Pohanish, R.P. (editor): Dichlorobenzenes. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 799-804.
  • Rosas Vazques, E., Campos Macias, P., Ochoa Tirado, J.G., Garcia Solana, C., Casanova, A. and Palomino Moncada, J.F.: Chloracne in the 1990s. Int. J. Dermatol. 35(9): 643-645, 1996.
  • Yoshida, T., et al.: Inhalation toxicokinetics of p-dichlorobenzene and daily absorption and internal accumulation in chronic low-level exposure to humans. Arch. Toxicol. 76(5-6): 306-315, 2002.

Date Last Revised: 05/10/2005

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Charcoal Tube (100/50 mg sections, 20/40 mesh)
    analytical solvent: Carbon Disulfide
    maximum volume: 3 Liters
    maximum flow rate: 0.05 L/min (TWA)
    maximum volume: 3 Liters
    maximum flow rate: 0.2 L/min (STEL)
    current analytical method: Gas Chromatography; GC/FID
    method reference: NIOSH Analytical Method (NIOSH 1003 [113 KB PDF, 7 pages])
    method classification: Partially Validated

** All Trademarks are the property of their respective owners.

Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF materials.