Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products

Pest Management Regulatory Agency
14 September 2012
ISSN: 1925-0649 (PDF version)
Catalogue number: H113-5/2012-08E-PDF (PDF version)

Executive Summary

The purpose of Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products is to notify registrants, pesticide regulatory officials, and the Canadian public of the re-evaluation status for the active ingredients chloropicrin, dazomet, metam sodium and metam potassium, and of label improvements for the soil fumigant products containing these active ingredients.

Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products summarizes comments made to the PMRA in response to the Re evaluation Note documents REV2010-10, Soil Fumigants Proposed Mitigation Measures, REV2010-12, Chloropicrin - Proposed Mitigation Measures, REV2010-13, Dazomet - Proposed Mitigation Measures, and REV2010-09, Metam Sodium and Metam Potassium - Proposed Mitigation Measures, published on 13 August 2010. Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products also provides the PMRA's responses to the comments received.

Background

Chloropicrin, dazomet, metam sodium and metam potassium are active ingredients under re evaluation by Health Canada's Pest Management Regulatory Agency (PMRA). These four active ingredients are being re-evaluated concurrently as part of a soil fumigant cluster. Soil fumigants are used to control soil pests or pathogens such as insects, nematodes, bacteria, fungi and weeds, which can disrupt plant growth and production. A fumigant is a volatile chemical that becomes a gas at relatively low temperatures (for example, chloropicrin), or a chemical that reacts to form a gas (for example, dazomet, metam sodium and metam potassium are converted to the active form, methyl isothiocyanate or MITC). In Canada, chloropicrin, dazomet, metam sodium and metam potassium are registered as pre-plant soil fumigants for use on a variety of terrestrial and/or greenhouse food/feed and non-food/non-feed crops, forests/woodlots, ornamentals, nurseries, seed beds and/or turf. The fumigants are applied and incorporated into the soil; treated soil is then sealed and subsequently aerated prior to planting. These active ingredients are also registered as antimicrobials, either as remedial wood preservatives (for example, structural timber) or as preservatives in industrial process fluids (for example, pulp and paper mills, water cooling towers). All currently registered uses are being considered in the re evaluation.

The regulatory approach and proposed label improvements for the soil fumigant cluster (including antimicrobial uses for these products) were first presented in Re-evaluation Note REV2010-10, Soil Fumigants Proposed Mitigation Measures, REV2010-12, Chloropicrin - Proposed Mitigation Measures, REV2010-13, Dazomet - Proposed Mitigation Measures, and REV2010-09, Metam Sodium and Metam Potassium - Proposed Mitigation Measures, published on 13 August 2010. This Re-evaluation Note describes this stage of PMRA's regulatory process for the re-evaluation of the soil fumigant products containing these active ingredients, as well as summarizes the Agency=s decision and the reasons for it. The regulatory process for the re-evaluation of antimicrobial products containing chloropicrin, dazomet, metam sodium or metam potassium is communicated in Re-evaluation Note REV2012-07, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Antimicrobial Products. The comments pertaining to soil fumigants received during the consultation process resulted in some changes to the proposed label improvements as described in the consultation documents. The PMRA also considered any incident reported to date to the PMRA for these active ingredients. Appendix I of Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products summarizes the comments received during the consultation and provides the PMRA's response to these comments.

Regulatory Strategy

The PMRA's re-evaluation of the soil fumigant cluster is ongoing. At this time, the PMRA is requiring label improvements to further limit user exposure and further protect bystanders and the environment. These label improvements are considered a first step in the re-evaluation of the Canadian uses of the products containing these active ingredients.

A key component of the label improvements for soil fumigant products containing chloropicrin, dazomet, metam sodium or metam potassium is the requirement of a Fumigation Management Plan (FMP) for all applications. A Fumigation Management Plan is an organized, written description of the required steps involved to help ensure a safe and effective fumigation. It will also assist in complying with pesticide product label requirements. Instructions for the preparation of a Fumigation Management Plan are required to be part of the product label. In addition, a Fumigation Management Plan template will be developed by the PMRA in consultation with registrants in order to help users meet the Fumigation Management Plan requirements. Chemical-specific label improvements are also required for all registered uses. Please refer to Re-evaluation Notes for chloropicrin (REV2012-09 Label Amendments for Soil Fumigants Products Containing Chloropicrin), dazomet (REV2012-10 Label Amendments for Soil Fumigant Products Containing Dazomet), and metam sodium/metam potassium (REV2012-11 Label Amendmens for Soil Fumigant Products Containing Metam Sodium of Metam Potassium) for a full description of the required amendments.

Additional Information

Any person may file a notice of objection regarding this decision for chloropicrin, dazomet, metam sodium and metam potassium within 60 days from the date of publication of this Re evaluation Note. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides and Pest Management portion of Health Canada's website (Request a Reconsideration of Decision) or contact the PMRA's Pest Management Information Service.

PMRA documents can be found on the Pesticides and Pest Management portion of Health Canada's website. PMRA documents are also available through the Pest Management Information Service.