Response to comments regarding tetrabutyltin
- Part I: comments on the proposed Risk management approach for non-pesticidal organotin compounds - pertaining to tetrabutyltin
- Part II: comments on the proposed Code of practice for tetrabutyltin
The final follow-up ecological assessment report for non-pesticidal organotin compounds was published by Environment Canada in the Canada Gazette, Part I, on August 8, 2009, under section 68 of the Canadian Environmental Protection Act, 1999 (CEPA). With respect to tetrabutyltin, this assessment report concluded that tetrabutyltin has the potential to cause environmental harm since it is a precursor to tributyltins, which are persistent and bioaccumulative compounds. Furthermore, it concluded that tetrabutyltin is entering, or may enter, the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity, as defined in paragraph 64(a) of CEPA.
On August 8, 2009, the proposed Risk management approach for non-pesticidal organotin compounds was published to solicit comments from stakeholders during the 60-day comment period. In this document, the Government of Canada indicated it would consider issuing a Code of practice for tetrabutyltin under paragraph 54(1)(d) of CEPA for the purpose of minimizing releases of tetrabutyltin to the aquatic environment by identifying best management procedures and practices for activities involving the import, distribution, manufacture and use of the substance.
On January 18, 2011, Environment Canada consulted with stakeholders on a proposed Code of practice for the management of tetrabutyltin in Canada, through a consultation document sent to stakeholders and published on Environment Canada’s website for a 30-day comment period.
The current document outlines the various comments received from stakeholders on the proposed Risk management approach for non-pesticidal organotin compounds as they pertain to tetrabutyltin and on the proposed Code of practice for tetrabutyltin. Also presented are the government response on how the comments have been considered in the preparation of the final version of the Code of practice for the nmnagement of tetrabutyltin in Canada that was published in November 2011. The comments received are presented in two parts: Part I includes comments on the proposed Risk management approach for non-pesticidal organotin compounds, and Part II includes comments on proposed Code of practice for the management of tetrabutyltin in Canada. The comments are further organized by topic according to their nature.
All comments received have been considered in the preparation of the final version of the Code of practice.
Part I: comments on the proposed Risk management approach for non-pesticidal organotin compounds - pertaining to tetrabutyltin
Topic: proposed risk management actions
We support the proposed risk management approach that would see the Ministerial Condition for tetrabutyltin rescinded and a Code of practice put in place.
We agree that minimizing releases of tetrabutyltin to the environment will contribute to the achievement of the government’s virtual elimination objective on tributyltins.
We support the decision that tetrabutyltin be added to the List of Toxic substances under Schedule 1 of CEPA.
Environment Canada is considering rescinding the ministerial condition for tetrabutyltin and adding this substance to the Domestic Substance List (DSL).
On July 6, 2011, tetrabutyltin was added to the List of Toxic Substances in Schedule 1 of CEPA.
Topic: ministerial conditions for tetrabutyltin
Although we are not subject to the ministerial condition for tetrabutyltin, our policies and current practices for managing tetrabutyltin are such that we are meeting the conditions that are identified therein; we intend to continue to do so until the proposed risk management action for tetrabutyltin has been implemented.
Environment Canada appreciates the efforts in meeting the conditions given that it is not a requirement.
Part II: comments on the proposed Code of practice for tetrabutyltin
Topic: recommended practices for reusable packaging
The requirement to rinse reusable packaging prior to returning it to the supplier (Section 5.1.1) is not practical in many cases (such as bulk trucks) and is not required by the existing ministerial condition. The code of practice should allow packaging to be simply sealed prior to it being returned to the supplier, sent for disposal or sent to companies specializing in the cleaning and reuse or recycling of the packaging.
We agree that any rinsate be treated as hazardous waste and this is already the current practice.
The proposed code already specified that if cleaning was not feasible or practical, the packaging should be sealed prior to returning it to the supplier. However, in light of the comment received, Environment Canada has revised the text in the final version of the code to put more emphasis on this practice by stating this option first.
Rinsate/residue from the washing of bulk trucks, though low volume, is another potential source of tetrabutyltin to the aquatic environment, and should be addressed in Section 5.
The definition of "reusable packaging" implicitly includes bulk truck. In light of this comment, Environment Canada has revised the code to explicitly mention bulk trucks in section 5 as one type of packaging, and therefore the procedures described in that section, including how rinsate/residue from washing should be addressed, would also apply to them.
Topic: recommended practices for non-reusable packaging
The proposal suggests that packaging, once rinsed to remove the tetrabutyltin, be disposed of as hazardous waste. This is not the current practice and would create additional and unnecessary expense to industry, and is also not required by the current ministerial condition. We therefore recommend that packaging that has been rinsed to remove tetrabutyltin should have no disposal restrictions.
In light of these comments, Environment Canada has revised the code of practice to recommend that once the packaging destined for disposal has been triple rinsed with a solvent capable of removing any residual tetrabutyltin, it can be sent to a non-hazardous waste facility.
Topic: transportation of packaging
The proposed code of practice does not directly address the transportation cycle as a potential source for tetrabutyltin to the environment. Regardless of the packaging type (drums, totes or bulk trucks), incidents during transportation, though low risk, are possible. We therefore recommend that Environment Canada includes in the final code of practice a requirement that any potential transportation carrier of tetrabutyltin (bulk or otherwise), be asked to demonstrate that they have a transportation emergency response plan in place, before the shipment is released to their care. This is because there is currently no such requirement under the Transportation of Dangerous Goods Regulations or any other Canadian legislation or regulations.
The transportation of dangerous goods is currently under the authority of the Transportation of Dangerous Goods Act, which is administered by Transport Canada. Given that such requirement does not fall under Environment Canada’s jurisdiction, this will not be addressed in the Code of Practice for tetrabutyltin developed under the Canadian Environmental Protection Act, 1999.
Topic: implementation of risk management actions
We support the implementation of a code of practice to replace the Ministerial Condition for tetrabutyltin. We recommend that the ministerial condition be rescinded immediately after the final code is in place, so as to prevent duplication. We note, however, that in the 2009 proposed risk management approach. The department indicated that the ministerial condition will be rescinded, whereas in the 2011 publication of the proposed code, the wording was changed to "would consider rescinding the ministerial Ccondition". We trust this softening of language is not an indication that Environment Canada is now reconsidering this position.
As the final code is published, Environment Canada will consider rescinding the ministerial condition and minimizing the overlap time. The department will also consider adding the substance to the Domestic Substance List (DSL).
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