At a glance
| Chemical family | Organochlorine — cyclodiene insecticide (stereoisomer of dieldrin) |
| CAS number | 72-20-8 |
| Classification | Not evaluated by IARC for carcinogenicity; Stockholm Convention Annex A (elimination); Canada SOR/2025-270 prohibited; one of the most acutely toxic pesticides ever manufactured |
| Where you encounter it | Agricultural soil in regions where it was applied (cotton, rice, sugarcane); environmental contaminant near former manufacturing sites; fish and wildlife |
| Sleep micro-environment relevance | Minimal — endrin was used in agriculture, not structural pest control, and degrades faster than aldrin/dieldrin. Present mainly through dietary exposure in historically contaminated regions |
Regulatory & certification status
| European Union | POP Regulation (EU) 2019/1021 — banned. Original dirty dozen Stockholm POP. Regulatory |
| United States | EPA cancelled all registrations (1984). CERCLA hazardous substance. Regulatory |
| Canada | Prohibited under the Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270), in force 30 June 2026. Regulatory — Canada authority |
| International | Stockholm Convention Annex A (elimination) — original dirty dozen POP. Not evaluated by IARC for carcinogenicity. Regulatory — International authority |
What it is
Endrin is a chlorinated cyclodiene insecticide and a stereoisomer of dieldrin (same molecular formula, different three-dimensional arrangement). It is one of the most acutely toxic pesticides ever produced — the oral LD50 in rats is approximately 3 mg/kg, making it far more dangerous in acute exposure than DDT or lindane. Endrin was used primarily against agricultural pests (cotton bollworm, rice borers, grasshoppers) and as a rodenticide. Unlike dieldrin, endrin has not been evaluated by IARC for carcinogenicity. Its global ban was driven by acute toxicity to humans, massive wildlife kills (particularly fish), and environmental persistence.
Where it shows up in bedding
Endrin has limited bedroom relevance. Unlike aldrin, dieldrin, and chlordane, endrin was not commonly used for structural termite control — its primary use was agricultural. It also degrades somewhat faster than its stereoisomer dieldrin. However, homes near former endrin manufacturing sites or heavily treated agricultural areas may have legacy contamination in soil. For most bedrooms, endrin is not a meaningful exposure source.
Citations
- ATSDR (1996). Toxicological Profile for Endrin. Agency for Toxic Substances and Disease Registry. Source Regulatory
- Stockholm Convention. Listing of Endrin — Annex A (Elimination). Source Regulatory
- Government of Canada. Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270). Source Regulatory
Frequently asked questions
Is endrin the same as dieldrin?
No. Endrin and dieldrin are stereoisomers — they have the same molecular formula but a different three-dimensional arrangement. Endrin is more acutely toxic than dieldrin but degrades faster in the environment. Both are banned under the Stockholm Convention dirty dozen.
Was endrin used in homes?
Rarely. Unlike aldrin, dieldrin, and chlordane, endrin was used primarily in agriculture (cotton, rice, sugarcane) rather than structural pest control. Its extreme acute toxicity made it unsuitable for residential applications. Homes near former manufacturing sites or heavily treated agricultural land are the most likely to have legacy contamination.
Related compounds
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.