Persistent Organic Pollutant — organochlorine pesticide

Chlordane in the bedroom

By — 19-year firefighter and entrepreneur. Published July 2026.

Chlordane is the most widely used termite pesticide in history. A complex mixture of chlorinated hydrocarbons, it was applied directly to the soil around building foundations from the 1950s through 1988 in the United States. IARC classifies it as Group 2B (possibly carcinogenic). The Stockholm Convention lists it as an Annex A POP. Canada prohibits it under SOR/2025-270 (in force 30 June 2026). Among the dirty dozen OCPs, chlordane has the strongest documented indoor persistence — it has been detected in the indoor air and dust of treated homes more than 20 years after the last application, making it one of the most relevant legacy pesticides for the sleep environment.

Chlordane — Embr Bedroom Chemistry Atlas

At a glance

Chemical familyOrganochlorine — cyclodiene insecticide mixture
CAS number57-74-9
ClassificationIARC Group 2B (possibly carcinogenic to humans); Stockholm Convention Annex A (elimination); Canada SOR/2025-270 prohibited
Where you encounter itLegacy termite treatments applied to building foundations; indoor air and dust in pre-1988 homes; food chain (particularly dairy, fish, and meat in contaminated regions)
Sleep micro-environment relevanceThe most relevant legacy pesticide for indoor environments. Detectable in indoor air and dust 20+ years after application. Homes treated before 1988 may still have measurable exposure during sleep

Regulatory & certification status

European UnionPOP Regulation (EU) 2019/1021 — banned. Original dirty dozen Stockholm POP. Regulatory
United StatesEPA cancelled all registrations (1988). The last use was termite control. CERCLA hazardous substance. California Proposition 65 listed (cancer). Regulatory
CanadaProhibited under the Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270), in force 30 June 2026. Regulatory — Canada authority
InternationalStockholm Convention Annex A (elimination) — original dirty dozen POP. IARC Group 2B (possibly carcinogenic). No exemptions remain. Regulatory — International authority

What it is

Chlordane is not a single compound but a complex mixture of at least 147 chlorinated hydrocarbons, with trans-chlordane, cis-chlordane, and heptachlor as the major components. Technical-grade chlordane was the dominant termite treatment in the United States from the 1950s until 1988. It was applied by injecting the mixture into the soil surrounding building foundations, creating a chemical barrier against subterranean termites. IARC classified chlordane as Group 2B based on sufficient evidence of carcinogenicity in animals (liver tumours in mice) and inadequate evidence in humans. Its extreme persistence in soil and ability to volatilise into indoor air for decades made it a defining case for the Stockholm Convention negotiations.

Where it shows up in bedding

Chlordane was not used in bedding products. Its bedroom relevance is structural and well-documented: the US EPA studied homes treated with chlordane and found that the compound volatilises from foundation soil into indoor air through cracks and openings in the building envelope. Multiple studies have detected chlordane in indoor air and house dust of treated homes 15-20 years after the last application. During the 8 hours of sleep, breathing contaminated air and contact with contaminated dust contribute to cumulative exposure. The US EPA estimated that residents of chlordane-treated homes could receive indoor air exposures exceeding those from diet.

The Embr Exposure Ledger: Chlordane

One chemical, several public questions, answered from independent datasets and joined here — the environment it shows up in, the body burden it carries, how it is regulated, and what actually reduces it.

This compound appears in 4 of the Embr Exposure Ledger’s 10 exposure datasets.
Is it in the air?
In U.S. outdoor air: about 2e-06 in a million added lifetime cancer risk.Source: EPA AirToxScreen (2020) — modeled ambient air-toxics concentrations and risk
At what level would it matter?
This compound does not appear in EPA’s consolidated screening-level table at all, so no published inhalation reference value exists to set against the findings on this page. That is common for newer substances and for replacements brought in after an older compound was restricted. What this page documents is that the compound is present, not how much of it would matter. Presence is not dose.Source: US EPA, Regional Screening Levels (RSL) Summary Table
Who releases it?
25 US facilities reported releasing it in 2024 across 16 states and territories. These are self-reported quantities leaving a facility, not levels anyone encountered, and the two national programs are not added together — they use different reporting thresholds.Source: US EPA, Toxics Release Inventory (TRI) Basic Data File, 2024 reporting year; Environment and Climate Change Canada, National Pollutant Release Inventory (NPRI), releases 1993-present
Does the law flag it?
Listed under California Proposition 65 for cancer since 1988. Carries an EU-wide binding classification as carcinogenic (category 2). That classifies the substance itself; it does not restrict any product. Banned in the EU under the persistent organic pollutants Regulation: manufacture, sale and use are prohibited. Specific exemptions apply.Source: California OEHHA Proposition 65 List (Safe Drinking Water and Toxic Enforcement Act of 1986)Source: EU CLP Annex VISource: EU POPs Regulation

Detection and body-burden figures are occurrence data, not a personal measurement or a health diagnosis. Part of the Embr Exposure Ledger — an open, cross-dataset chemical join (download the data), reusable with attribution.

Citations

  1. IARC (1991). Chlordane and Heptachlor. IARC Monographs Vol. 53. Source Regulatory
  2. ATSDR (1994). Toxicological Profile for Chlordane. Agency for Toxic Substances and Disease Registry. Source Regulatory
  3. Government of Canada. Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270). Source Regulatory

Frequently asked questions

  • Is chlordane still in my home?

    If your home was built before 1988 and had a professional termite treatment in regions where chlordane was used (most of the United States, Australia, Japan), the compound may still be detectable in indoor air and household dust. Chlordane volatilises slowly from foundation soil and enters indoor air through cracks and openings. Professional environmental testing can determine whether your home has residual chlordane exposure.

  • What is technical-grade chlordane?

    Technical-grade chlordane is a complex mixture of at least 147 chlorinated compounds, not a single pure chemical. The major components are trans-chlordane, cis-chlordane, heptachlor, and trans-nonachlor. This is why environmental monitoring for chlordane exposure typically measures multiple components. The mixture was sold under brand names including Velsicol, Termide, and Octachlor.

Related compounds

  • Chlordecone — another chlorinated insecticide listed for elimination, notorious in the Antilles
  • Endosulfan — another Stockholm Annex A organochlorine insecticide, banned without exemptions
  • Heptachlor — a major component of technical-grade chlordane
  • Dieldrin — another OCP used for termite control that persists indoors
  • DDT — another original dirty dozen POP
  • Mirex — another banned OCP used as both pesticide and flame retardant

Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.

Last reviewed 2026-07-07. If you find a factual error, contact us.