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Canada - Final Regulatory Action
Tributyl tin compounds CAS number:
1461-22-9, 1983-10-4, 2155-70-6, 24124-25-2, 4342-36-3, 56-35-9, 85409-17-2
Date circular:

Chemical name: TBT

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 of antifouling paint containing tributyltin compounds are prohibited from import, sale or use in Canada.

Pesticide use or uses that remain allowed:

Formulations for the pest control uses in the following categories are registered in Canada.
- Material preservative
- Wood preservative
- Slimicide

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

Summary of the final regulatory action:

Use of TBT antifouling paints represent an unacceptable risk to the marine environment. Alternative products currently registered in Canada offer an adequate period of control of fouling organisms to meet the needs of Canadian users.
As a result of the review, the registrations of all tri-N-butyl tin based TBT antifouling paints, and their associated registered concentrates and active ingredient, were phased out during 2002.
The registrant had agreed to conduct a recall of any unsold product to ensure that there is no product in the channels of trade after January 1, 2003.

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

Summary of known hazards and risks to the environment:

TBT is an exclusively anthropogenic chemical. A detailed review conducted by Environment Canada concluded that TBT is extremely toxic to aquatic organisms, and is sufficiently persistent and bioaccumulative to warrant virtual elimination from the Canadian environment.
Using the effect of imposex on molluscs to monitor recovery from TBT contamination, studies indicate that regulatory control of TBT antifouling paints in Canada prior to 1999 had not eliminated the problem.
It was determined that the continued use of TBT in antifouling paints poses an unacceptable risk to Canadian waters, based on non-target toxicity to aquatic organisms, persistence in the environment, and bioaccumulation in aquatic organisms.
Because of the long persistence of TBT in sediment, TBT concentrations in marine sediments in some locations may exceed chronic toxicity thresholds for years to come.

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

Regulatory action will remove this source of TBT to the aquatic environment. Although persistence in the marine environment at some locations will maintain elevated levels for some time, removing this source of input will allow recovery to occur.

Date of entry into force of the final regulatory action: 31/10/2002