Consultation document on proposed risk management measure for tetrabutyltin: chapter 1

Substance Containing the Grouping (C₄H₉)₄Sn

Environment Canada

December 2010

Download Consultation Document (PDF Format, 121 KB)

Table of Contents

• 1 Introduction
• 2 Industrial Use of Tetrabutyltin
  • 2.1 Current Uses and Industrial Sectors
  • 2.2 Releases and Exposure Sources to the Environment
• 3 Existing Risk Management Activities for Tetrabutyltin
  • 3.1 Canada
  • 3.2 International
• 4 Next Steps
• 5 References
• Annex A: Proposed Code of Practice for the Management of Tetrabutyltin in Canada

1 Introduction

Organotin substances are tin compounds having 1, 2, 3 or 4 organic groups attached and are designated as mono-, di-, tri- or tetraorganotin depending on the number of tin-carbon bonds in the molecule. Organotins are mainly used in the vinyl processing industry and as pesticides. Tetrabutyltin, the substance which is the subject of this consultation document, has the chemical formula (C₄H₉)₄Sn and is used in Canada as a starting material for the synthesis of mono- and dibutyltin compounds for use in polyvinyl chloride (PVC) processing.

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 1999) [EC, 2009a]. 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 1999.

In the Risk Management Approach for Non-Pesticidal Organotin Compounds that was published in August 2009 (EC, 2009b), the Government of Canada indicated it would consider issuing a Code of Practice for tetrabutyltin under paragraph 54(1)(d) of CEPA 1999 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.

Environment Canada is developing a Code of Practice for tetrabutyltin. This is being proposed to meet the risk management objective of achieving the lowest level of releases that are technically and economically feasible. A draft of the Code of Practice is presented in Annex A.

This consultation focuses on the environmental and economic issues associated with the proposed Code of Practice. The purpose of this consultation is to:

• Inform interested stakeholders of the proposed Code of Practice; and
• Provide an opportunity for interested stakeholders to comment on the proposed Code of Practice.

The Government of Canada is committed to providing interested and affected parties with the opportunity to take part in consultations at all stages of the Code's development. All interested parties may comment on the proposed Code of Practice in writing to the contact provided in section 4 of this document.