<< 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: 1,4,5,6,7,8,8a-Heptachloro-3a,4,7,7a-tetra-hydro-4,7-methanoidene (principal ingredient)

OSHA IMIS Code Number: 1369

Chemical Abstracts Service (CAS) Registry Number: 76-44-8

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: PC0700000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 2761 151

NIOSH Pocket Guide to Chemical Hazards, Heptachlor: 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 -- 0.5 mg/m3 TWA; Skin

Construction Industry: 29 CFR 1926.55 Appendix A -- 0.5 mg/m3 TWA; Skin

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 0.5 mg/m3 TWA; Skin

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 0.05 mg/m3 TWA; Skin; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 0.5 mg/m3 TWA; Skin; Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

Carcinogenic Classification:

Environmental Protection Agency (EPA): Group B2, probable human carcinogen

International Agency for Research on Cancer (IARC): Group 2B, possibly carcinogenic to humans

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 35 mg/m3

Potential Symptoms: In animals: tremors, convulsions, lung, liver damage, reproductive toxicity; [potential occupational carcinogen]

Health Effects: Mutagen (HE2) Cumulative liver damage (HE3) CNS effects (Convulsions) (HE7)

Affected Organs: CNS, liver


  1. Heptachlor is an OSHA Select carcinogen. The cancer site in animal studies is the liver.
  2. Manufacture of heptachlor in the U.S. ended in 1987 and the EPA prohibited sale, distribution and shipment of existing stocks in 1988. Current exposure may be highest in and around structures treated with heptachlor (or technical-grade chlordane which contains ~10 % heptachlor) for termite and ant control. Use of heptachlor for fire ant control in power transformers is still permitted.
  3. EPA's oral reference dose (daily oral exposure likely to be without an appreciable risk of noncancer deleterious effects during a lifetime) of heptachlor is 0.0005 mg/kg/day.
  4. Heptachlor epoxide is the major metabolite of heptachlor and is often found at much higher levels in adipose tissue (fat) than is heptachlor.
  5. Regression analysis of data collected by the EPA between 1969 and 1983 on pesticide residues in human fat resulted in a significant association between heptachlor epoxide levels and diagnoses of non-Hodgkin's lymphoma.

Literature Basis:

  • Agency for Toxic Substances and Disease Registry (ATSDR): Draft toxicological profile for heptachlor and heptachlor epoxide. Atlanta: ATSDR, (September) 2005, 177 pp.
  • NIOSH Pocket Guide to Chemical Hazards: Heptachlor.
  • International Agency for Research on Cancer: Chlordane and Heptachlor (Group 2B). IARC Summaries & Evaluations, Vol 79, 2001.
  • International Chemical Safety Cards (WHO/IPCS/ILO): Heptachlor.
  • EPA Air Toxics Website: Group B2, probable human carcinogen. U.S. Environmental Protection Agency Technology Transfer Network.
  • Pohanish, R.P. (editor): Heptachlor. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1225-1227.
  • Quintana, P.J.E., et al.: Adipose tissue levels of organochlorine pesticides and polychlorinated biphenyls and risk of non-Hodgkin's lymphoma. Environ. Health Perspect. 112(8): 854-861, 2004.

Date Last Revised: 01/11/2006

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: OSHA Versatile Sampler (OVS-2) - 13 mm XAD-2 Tube (270/140 mg sections, 20/60 mesh) with Glass Fiber Filter enclosed
    analytical solvent: Toluene
    maximum volume: 60 Liters
    maximum flow rate: 1.0 L/min
    current analytical method: Gas Chromatography; GC/ECD
    method reference: OSHA Analytical Method (OSHA PV2029)
    method classification: Partially Validated

Bulk Method:

  • Limit the amount of bulk submitted to one gram or one mL.

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