Re-evaluation Note REV2012-07, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Antimicrobial Products

Pest Management Regulatory Agency
14 September 2012
ISSN: 1925-0649  (PDF version)
Catalogue number: H113-5/2012-07E-PDF (PDF version)

Executive Summary

The purpose of this document 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 antimicrobial products containing these active ingredients.

This Re-evaluation Note 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. This Re-evaluation Note also provides the PMRA's responses to the comments received.

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 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, sealed and then 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 considered in the re-evaluation.

The regulatory approach and proposed label improvements for the soil fumigant cluster 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 antimicrobial 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 soil fumigant products containing chloropicrin, dazomet, metam sodium or metam potassium is communicated separately in Re-evaluation Note REV2012-08, Chloropicrin, Dazomet, Metam Sodium and Metam Potassium Label Improvements for Soil Fumigant Products. Comments pertaining to antimicrobial products received during the consultation process resulted in some changes to the proposed label improvements as described in the consultation documents. Appendix I 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.

Appendix II outlines the required label amendments for antimicrobial products containing chloropicrin. Appendix III outlines the label amendments required for antimicrobial products containing dazomet. Appendix IV outlines the label amendments required antimicrobial products containing metam sodium and metam potassium.

Additional Information

Any person may file a notice of objection regarding this decision of label improvements 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) at www.hc-sc.gc.ca/cps-spc/pest/part/protect-proteger/publi-regist/index-eng.php#rrd 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.