Response to comments on proposed Prohibition of Certain Toxic Substances Regulations: chapter 2


Tributyltins (TBTs)

Topic Comment Summary Response
International Jurisdictions A non-governmental organization representative commented that other jurisdictions, such as the European Union, have adopted a decision in May 28, 2009 to prohibit the use of triorganotin compounds and dibutyltin in articles. They requested that Canada follow this approach and expand the Regulations to include prohibition of dibutyltin at a minimum or to establish clear numerical limits similar to those of the European Union.

The Regulations are one of several measures in place to manage the risks associated with TBTs in the Canadian environment.  Other measures in place include a Code of Practice and an Environmental Performance Agreement that are intended to manage the release of these substances or of compounds that may contain these substances.

During the development of the Regulations, consideration was given to actions taken by other jurisdictions.     

In the case of dibutyltins, Health Canada’s conclusion of the human health assessment conducted in 2003 was that it did not meet the criteria listed in subsection 64(c) of CEPA 1999, and therefore, no risk management actions are being proposed at this time.

Similarly, Environment Canada’s conclusion of the 2009 ecological assessment for dibutyltins was that they did not meet the criteria listed in subsection 64(a) or (b) of CEPA 1999 due to industry-wide stewardship practices in place to limit their potential environmental releases, which are being verified under an Environmental Performance Agreement.

General Comments A non-governmental organization representative indicated that there should be mandatory controls on tetrabutyltin, mono- and dibutyltins in place of non-regulatory mechanisms, and that it should be released to the public for review and comments.

The risk management tools in place for managing potential releases of tetrabutyltin, monobutyltins and dibutyltins have been released to the public for comments prior to their finalisation.

In the case of tetrabutyltin, the proposed Code of Practice was published for public comments in January 2011. Comments have been considered and the final Code was published on November 5, 2011. Environment Canada intends to verify the degree of implementation of the Code and to publish the results on our website. 

As for mono- and dibutyltins, these were not concluded to be toxic; however, an Environmental Performance Agreement (EPA) was put in place to verify whether suitable management practices and procedures were in place to prevent their release into the aquatic environment. The draft EPA on tin stabilizers was published in April 2007 for public review.  Apart from a clarification question, no comments were received, and the final EPA was signed in March 2008. Furthermore, annual progress reports are published on Environment Canada’s website.

  An industry stakeholder suggested that the proposed regulations not interfere with the Code of Practice objectives and /or the development process.

The Regulations and the Code of Practice do not interfere with one another.

The Regulations prohibit the manufacture, use sale, offer for sale or import of the product tetrabutyltin containing a concentration greater than 30% by weight of TBTs.

The existing activities involving the import, distribution, manufacture and use of tetrabutyltin are covered by the Code of Practice as they pertain to products containing less than or equal to 30% by weight of TBTs. 

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