Re-evaluation Decision RVD2020-10, Linuron and its associated end-use products

Pest Management Regulatory Agency
5 November 2020
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2020-10E-PDF (PDF version)

Summary

Table of contents

• Re-evaluation of linuron and associated end-use products
• Re-evaluation decision for linuron
• Next steps
• Other information
• Appendix I - Registered linuron products in Canada

Re-evaluation of linuron and associated end-use products

Under the authority of the Pest Control Products Act, all registered pesticides must be re-evaluated by Health Canada's Pest Management Regulatory Agency (PMRA) to ensure that they continue to meet current health and environmental standards and continue to have value. The re-evaluation considers data and information from pesticide manufacturers, published scientific reports and other regulatory agencies, as well as comments received during public consultations. Health Canada applies internationally accepted risk assessment methods as well as current risk management approaches and policies.

Linuron is a selective systemic herbicide registered for the control of annual and perennial broadleaf and grassy weeds in: corn (field and sweet), soybean, potato, wheat, barley, oats, carrots, parsnip, dill, caraway, coriander, celery, asparagus, sweet white lupins, fruit trees (peach, apple, pear, plum, cherry), chokecherries, Saskatoon berries, and shelterbelts (Western Canada). Currently registered products containing linuron can be found in the Pesticide Label Search and in Appendix I. The Proposed Re-evaluation Decision PRVD2012-02, Linuron, ^{Footnote 1} containing the evaluation of linuron and proposed decision, underwent a 60-day consultation period ending on 25 September 2012. PRVD2012-02 proposed the cancellation of linuron and its associated end-use products due to health and environmental risks of concern.

Health Canada received comments and information relating to the health, environmental and value assessments. Commenters are listed in Appendix II of Re-evaluation Decision RVD2020-10, Linuron and its associated end-use products. These comments are summarized in Appendix III of RVD2020-10 along with responses by Health Canada. These comments and new data/information did result in revisions to the toxicology, dietary, occupational, environmental, and value assessments (see Science evaluation update of RVD2020-10), and did result in changes to the proposed re-evaluation decision as described in PRVD2012-02.

A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2012-02, and further information used in the re-evaluation decision is listed in Appendix XI of RVD2020-10. Therefore, the complete reference list of all information used in this final re-evaluation decision includes both the information set out in the Reference section of PRVD2012-02 and the information set out in Appendix XI of RVD2020-10.

This document (RVD2020-10) presents the final re-evaluation decision^{Footnote 2} for the re-evaluation of linuron, including the required amendments (risk mitigation measures) to protect human health and the environment, and any label amendments required to bring labels to current standards. All products containing linuron that are registered in Canada are subject to this re-evaluation decision.

Re-evaluation decision for linuron

Health Canada has completed the re-evaluation of linuron. Under the authority of the Pest Control Products Act, Health Canada has determined that continued registration of products containing linuron is acceptable. An evaluation of available scientific information found that some uses (carrots, parsnip, potato, asparagus, shelterbelts) of linuron products meet current standards for protection of human health and the environment when used according to revised conditions of registration, which include new mitigation measures. The following uses of linuron are cancelled since health risks were not shown to be acceptable:

• Tree fruit (apple, peach, pear, plum/prune, cherry), corn (field and sweet), wheat, barley, oats, soybean, celery, Saskatoon berries, chokecherries, dill, coriander, caraway, sweet white lupins, and pre-emergent combined with post-harvest application to asparagus.

Label amendments, as summarized below and listed in Appendix X of RVD2020-10, are required.

Risk mitigation measures

Registered pesticide product labels include specific directions for use. Directions include risk mitigation measures to protect human health and the environment and must be followed by law. The required amendments, including any revised/updated label statements and/or mitigation measures, as a result of the re-evaluation of linuron, are summarized below. Refer to Appendix X of RVD2020-10 for details.

Uses not supported by manufacturers for re-evaluation and will be removed from all product labels:

• Field corn (post-emergence);
• Aerial and handheld applications.

Cancelled uses to be removed from all product labels:

• Tree fruit (apple, peach, pear, plum/prune, cherry), corn (field and sweet), wheat, barley, oats, soybean, celery, Saskatoon berries, chokecherries, dill, coriander, caraway, sweet white lupins, and pre-emergent combined with post-harvest application to asparagus.
• Airblast and right-of way application equipment.

Cancelled uses with an extended phase out schedule:

A subset of cancelled uses were found to lack suitable alternatives for the management of weeds, for which growers would face significant challenges:

• Chokecherries (fall seeded plantings), dill, coriander, caraway, celery, and sweet white lupins.

As a result, the implementation of the re-evaluation decision for these cancelled minor specialty crops will be delayed for an additional two years to allow growers to find pest management solutions. During this extended period, the overall exposure to human health and the environment will be significantly reduced by the removal of other cancelled uses, as well as through the implementation of additional interim mitigation measures that will be required when applying linuron to these cancelled minor uses. The risks to human health and the environment are therefore considered acceptable for an additional two years for these cancelled minor uses.

General label improvements:

• Update and/or revise the use directions for retained uses according to required risk mitigation measures.
• Replace 'guarantee' with 'active ingredient' on all product labels.

Human health

Risk Mitigation:

To protect human health from exposure, the following risk-reduction measures are required for uses with continued registration (carrots, parsnip, potato, asparagus and shelterbelts):

• Revised maximum application rates
  • Limit pre-emergent and post-emergent applications to carrots to a maximum annual application rate of 1.68 kg a.i./ha
  • Limit pre-emergent and post-emergent applications to parsnips to a maximum annual rate of 1.50 kg a.i./ha
  • Limit pre-emergent application to potatoes to a maximum annual rate of 1.78 kg a.i/ha
  • Limit pre-emergent or post-emergent application to asparagus to a maximum annual application rate of 1.63 kg a.i./ha
  • Limit dormant stage application to shelterbelts to a maximum annual application rate of 2.16 kg a.i./ha
• To protect consumers, increase the plant back interval restriction from 4 months to 12 months for carrots, potato, and parsnip.
• To protect mixers/loaders and applicators: increased personal protective equipment (PPE), addition of engineering controls (closed mixing loading and closed cab application), and restrictions on some types of application equipment.
• To protect post application workers: increased restricted-entry intervals (REIs) for all activities.
• To protect bystanders from spray drift: require a statement to promote best management practices to minimize human exposure from spray drift or spray residues resulting from drift.

Interim Risk Mitigation:

To protect human health from exposure, the following interim risk-reduction measures are required for cancelled uses with an extended phase out period (chokecherries, dill, coriander, caraway, celery and sweet white lupins):

• Interim maximum application rates
  • Limit pre-emergent application to chokecherries (fall seeded plantings) to a maximum annual application rate of 1.70 kg a.i./ha
  • Limit pre-emergent and post-emergent applications to dill to a maximum annual rate of 1.50 kg a.i./ha
  • Limit post-emergent application to coriander and caraway to a maximum annual rate of 0.80 kg a.i/ha
  • Limit post-emergent application to celery to a maximum annual application rate of 1.68 kg a.i./ha
  • Limit pre-emergent application to sweet white lupins to a maximum annual application rate of 1.49 kg a.i./ha
• To protect post application workers: increased interim restricted-entry intervals (REIs) for all activities.

Environment

Label improvements to meet current standards:

• Updated discharge of effluent statements;
• Updated storage statements.

Risk Mitigation:

To protect the environment, the following risk-reduction measures are required for uses with continued registration (carrots, parsnip, potato, asparagus and shelterbelts):

• Standard label statements are required to minimize potential risks resulting from runoff;
• Standard hazard statements to inform users of the potential toxic effects to sensitive biota;
• Aerial application is prohibited;
• Buffer zones are required to mitigate risks from spray drift.

Interim Risk Mitigation:

To protect the environment, the following interim risk-reduction measures are required for cancelled uses with an extended phase out period (chokecherries, dill, coriander, caraway, celery and sweet white lupins):

• Interim buffer zones to mitigate risks from spray drift.

Value

Label improvements to meet current standards:

• Remove any vague or non-specific claims that the product can be tank mixed with another pesticide.
• Verify that the resistance management statement on each end-use product label is up-to-date.

Next steps

To comply with this decision, the required amendments (mitigation measures and label updates) must be implemented on all product labels no later than 24 months after the publication date of RVD2020-10. Accordingly, both registrants and retailers will have up to 24 months from the date of this decision document to transition to selling the product with the newly amended labels. Similarly, users will have the same 24-month period from the date of RVD2020-10 to transition to using the newly amended labels, which will be available on the Public Registry.

Refer to Appendix I for details on specific products impacted by this decision.

Other information

Any person may file a notice of objection^{Footnote 3} regarding this decision on linuron and its associated end-use products within 60 days from the date of publication of RVD2020-10. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides section of the Canada.ca website (Request a Reconsideration of Decision) or contact the PMRA's Pest Management Information Service by phone (1-800-267-6315) or by e-mail (pmra.info-arla@hc-sc.gc.ca).

The relevant confidential test data on which the decision is based (as referenced in PRVD2012-02 and Appendix XI of RVD2020-10) are available for public inspection, upon application, in the PMRA's Reading Room (located in Ottawa). For more information, please contact the PMRA's Pest Management Information Service.

Appendix I - Registered linuron products in Canada