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Canada - Final Regulatory Action
Endrin CAS number:
Date circular:

Chemical name: 2,7:3,6-Dimethanonaphth[2,3-b]oxirene, 3,4,5,6,9,9-hexachloro-1a,2,2a,3,6,6a,7,7a-octahydro-, (1a.alpha.,2.beta.,2a.beta.,3.alpha.,6.alpha.,6a.beta.,7

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

All formulations prohibited from import, sale or use.

Pesticide use or uses that remain allowed:


The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

Registration discontinued in 1990; no pest control uses allowed as of December 31, 1994.

The reasons for the final regulatory action were relevant to: Environment

Summary of known hazards and risks to the environment:

- Persistent in the environment due to insolubility in water, high solubility in fats, adsorption to particulate matter, and resistance to chemical, physical, and microbiologic degradation
- In the air, mainly associates with particulate matter, but small amounts may exist in the vapour phase; will react with hydroxyl radicals with a half-life of 1.45 hours and photodegrade to y-ketoendrin with a half-life of 7 days.
- Adsorbs strongly to soil, where it is immobile and will persist with a half-life of $ 12 years. Leaching to groundwater is possible under certain conditions. Small amounts may volatilize from soil and/or be carried by dust particles in the air.
- Does not hydrolyse or biotransform in water and the half-life can range 16 weeks to many years. It will extensively adsorb to sediment.
The bioaccumulation factors (BCFs) for endrin range 2,720 to 12,600 with fish BCFs from 1,335 to 10,000; BAFs for Trophic Levels 3 and 4 are 15,033.47 and 13,048.54, respectively; values for ecological magnification in fish and snail are 1,335 and 49,218, respectively; and, the values for biodegradability index in fish and snail are 0.009 and 0.0124, respectively.
When in use, endrin entered the food chain of mammals, birds, fishes, and other living matter. It is extremely toxic to birds, fish, and other aquatic life, and it is toxic to bees. Like other organochlorine insecticides, endrin will negatively impact the reproductive success of birds by acute intoxication, fatality, and eggshell thinning.

Expected effect of the final regulatory action in relation to the environment:

Chemical no longer registered for pest control use in Canada. Source of entry into environment removed.

Date of entry into force of the final regulatory action: 31/12/1990