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Canada - Final Regulatory Action
Terbufos CAS number:
13071-79-9
Date circular:
12/06/2021

Chemical name: Phosphorodithioic acid, S-[[(1,1-dimethylethyl)thio]methyl] O,O-diethyl ester

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 registered formulations containing terbufos and all registered uses of this active ingredient are prohibited.

Pesticide use or uses that remain allowed:

Not applicable.

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

Summary of the final regulatory action:

Sale of pesticides containing terbufos was prohibited in Canada effective May 1, 2012. The use of products containing terbufos was prohibited after August 1, 2012.

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

Summary of known hazards and risks to the environment:

n-Octanol-water partition coefficients indicate potential for a bioaccumulation of the parent compound and limited bioaccumulation potential for terbufos sulfone or terbufos sulfoxide. Bioconcentration studies with fish indicate a potential for bioconcentration.
Based on the available toxicity data, the risk was classified as high to extremely high for aquatic organisms and in most cases high to extremely high for birds. Similarly, risk to mammals was classified as low for large mammals to high for small mammals. The high risk of terbufos on non-target species has been documented by incident reports of adverse effects.

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

Terbufos can cause harm to the environment. Preventing use of this chemical protects the environment and non-target organisms from the risk of exposure.
The risk of environmental exposure to terbufos was reduced in a manner that was the least disruptive to the need to protect agricultural crops from pests.

Date of entry into force of the final regulatory action: 23/03/2004