Re-evaluation Note REV2010-02, Re-evaluation Work Plan for Glyphosate

02 February 2010
HC Pub: 100049
ISBN: 978-1-100-14773-4 (print version)
ISBN: 978-1-100-14774-1 (PDF version)
Catalogue number: H113-5/2010-2E (print version)
Catalogue number: H113-5/2010-2E-PDF (PDF version)

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Introduction

In Canada, glyphosate is under re-evaluation by Health Canada's Pest Management Regulatory Agency (PMRA). The PMRA's pesticide re-evaluation program considers potential risks as well as the value of pesticide products to ensure they meet modern standards established to protect human health and the environment. Under the authority of section 16 of the Pest Control Products Act, the registrants of glyphosate were served notice of the initiation of the re-evaluation of glyphosate in November-December of 2009. This Re-evaluation Note outlines a work plan and timeline for review as well as summarizes anticipated needs relevant to the re-evaluation of glyphosate.

Glyphosate is a non-selective herbicide that has been registered in Canada under various forms. Currently registered glyphosate and its other forms include the following: glyphosate acid (GPS); glyphosate potassium salt (GPP); glyphosate mono-ammonium salt or diammonium salt (GPM); glyphosate isopropylamine salt or ethanolamine salt (GPI); glyphosate trimethylsulfonium salt (GPT, also known as glyphosate TMS); and glyphosate dimethylamine (GPX). Glyphosate is registered on the following Use-Site Categories:

• Forests and Woodlots (Use-Site Category 4);
• Industrial Oil Seed Crops and Fibre Crops (Use-Site Category 7),
• Terrestrial Feed Crops (Use-Site Category 13);
• Terrestrial Food Crops (Use-Site Category 14);
• Industrial and Domestic Vegetation Control Non-food Sites (Use-Site Category 16);
• Ornamentals Outdoors (Use-Site Category 27); and
• Turf (Use-Site Category 30).

Glyphosate products are formulated as liquids or solids and can be applied at preplanting, after emergence, preharvest or after harvest using ground or aerial equipment.

The work plan discussed below outlines the anticipated risk assessment and data needs. The United States Environmental Protection Agency (USEPA) is re-evaluating glyphosate as part of its registration review program, and has published a final registration review work plan.¹ The PMRA will be working cooperatively with the USEPA on the re-evaluation of glyphosate. The overall Canadian re-evaluation timelines will be closely aligned with those of the USEPA. Currently, the assessment is targeted for completion in 2014.

Re-evaluation Work Plan

Human Health Assessment

• Consideration will be given to any new toxicological data including data being generated for the USEPA and available in relevant published scientific literature.
• The assessment will include application of the Pest Control Products Act factors.²
• Occupational and residential risk assessments will be revised if required should there be any changes to toxicology endpoints or the Pest Control Products Act factors.
• Dietary risk is well below the levels of concern based on current modern assessments. New assessments will not be needed provided there are no changes to toxicology endpoints as a result of the Pest Control Products Act factor considerations.
• The PMRA will conduct new assessments if required and workshare with the USEPA.

Environmental Risk Assessment

• Additional environmental data that have been submitted or required in recent years will be considered in the re-evaluation of glyphosate as well as any relevant scientific literature.
• Environmental risk mitigation measures will be reviewed to ensure consistency among labels (for example, spray buffer zones).
• The major transformation products of glyphosate, including amino methyl phosphonic acid (AMPA), will be considered as part of the scheduled re-evaluation of glyphosate.
• The PMRA will conduct new assessments and workshare with the USEPA as needed.

Formulant

• Polyethoxylated tallow amines (POEA) is a family of many compounds. In Canada, some glyphosate end-use products contain the surfactant POEA. A health risk assessment as well as an environmental risk assessment (including consideration of effects on non-target organisms) of the POEA/glyphosate combination will be conducted as part of the scheduled re-evaluation of glyphosate.

Chemistry

• A reassessment of the impurity profile of glyphosate will be conducted.

Data Requirements

• While at this time no new additional data requirements have been identified, the PMRA will examine the data requested by the USEPA as part of its registration review program.

Additional Information

If there are any questions or for additional information regarding this work plan, please contact Publications.

PMRA documents can be found on our website at www.healthcanada.gc.ca/pmra. PMRA documents are also available through the Pest Management Information Service.

The USEPA documents for glyphosate are available on the USEPA  Pesticide Registration Status page.