Re-evaluation Decision RVD2019-11, Permethrin and Its Associated End-use Products

Pest Management Regulatory Agency
26 August 2019
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2019-11E-PDF (PDF version)

Summary

Table of Contents

• Re-evaluation Decision
• Outcome of Revised Science Evaluation
• Regulatory Decision for Permethrin
• Risk Mitigation Measures
• Next Steps
• Other Information

Re-evaluation Decision

Under the authority of the Pest Control Products Act, all registered pesticides must be regularly 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. The PMRA applies internationally accepted risk assessment methods as well as current risk management approaches and policies.

Permethrin is a broad-spectrum synthetic pyrethroid insecticide. It is registered for use on a wide range of crops including grains and oilseeds, legumes, horticultural crops, mushroom houses, ginseng, greenhouse and field-grown ornamentals as well as tobacco. It is also registered for use on livestock, companion animals, forestry and woodlots, feedlots, termite treatment, pet premises, kennels, indoors and outdoors of homes, agricultural, commercial and institutional buildings, military clothing, mosquito netting and soil around honeybee hives. In Canada, there are over 400 registered pesticides containing permethrin. Information on these products can be found through Health Canada’s label transcription service.^{Footnote 1}

The regulatory approach for the re-evaluation of permethrin was first presented in the Proposed Re-evaluation Decision PRVD2017-18, Permethrin and its End-use Products,^{Footnote 2} which underwent a 90-day consultation period ending on 18 January 2018. PRVD2017-18 proposed mitigation measures to further protect human health and the environment, including cancellation of use in mushroom houses and certain application types (fogger, handheld mist blower/airblast, indoor broadcast in residential areas, indoor solid fogger), as well as a mandatory 10-metre vegetative strip for agricultural products.

Health Canada received comments and new data/information relating to the health, value and environmental risk assessments. These comments are summarized in Appendix I of RVD2019-11 along with the responses by Health Canada. These comments and new data/information resulted in revisions to the risk assessments (see Science Evaluation Update section of RVD2019-11), and subsequently, in changes to the proposed regulatory decision as described in PRVD2017-18. A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2017-18, and further data used in the re-evaluation decision are listed in Appendix VI of RVD2019-11.

This document (RVD2019-11) presents the final regulatory decision^{Footnote 3} for the re-evaluation of permethrin, including the required risk mitigation measures to protect human health and the environment. All products containing permethrin that are registered in Canada are subject to this re-evaluation decision.

Outcome of Revised Science Evaluation

Following the consultation on the proposed re-evaluation decision, Health Canada revised the occupational risk assessment based on the comments and new data/information received. As a result, use of permethrin in mushroom houses is acceptable for continued registration with implementation of new mitigation measures and label amendments. Also, mechanically-pressurized handheld sprayer applications of permethrin for mists, aerosols, and fogs, indoor structural manually-pressurized handwand application as well as rod and sub-slab injector applications for termites are acceptable for continued registration provided that additional personal protective equipment (PPE) is worn, when necessary. Health risks have not been shown to be acceptable for electric mistblower applications to attic spaces when these products are used according to current label directions, or when additional mitigation measures are considered. The environmental risks associated with the use of permethrin and associated end-use products are acceptable when permethrin products are used according to the mitigation measures including the vegetative strip for agricultural products and revised label directions.

Regulatory Decision for Permethrin

Health Canada has completed the re-evaluation of permethrin. Under the authority of the Pest Control Products Act, Health Canada has determined that continued registration of products containing permethrin is acceptable. An evaluation of available scientific information found that most uses of permethrin products meet current standards for protection of human health and the environment when used according to revised label directions which include new mitigation measures. Certain uses and application methods for permethrin are being cancelled to address potential risks of concern to human health. Label amendments, as summarized below and listed in Appendix III of RVD2019-11, are required for all technical and end-use products. No additional data are requested at this time.

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 key risk-reduction measures and label updates required, as a result of the re-evaluation of permethrin, are summarized below. Refer to Appendix III of RVD2019-11 for details.

Human Health

To protect workers, homeowners, those entering treated areas etc. from occupational/residential exposure, the following risk-reduction measures are required for continued registration of permethrin in Canada:

• Cancellation of electric mistblower and total release fumigating fogger applications.
• Limiting application timing in mushroom houses.
• The rate for application to residential yards reduced to 0.123 g a.i./m2.
• Increased PPE.
• Increased restricted entry-intervals (REIs).
• Additional label statements are required for domestic- and commercial-class products used in residential areas.

To protect consumers from dietary exposure, the following risk-reduction measures are required for continued registration of permethrin in Canada:

• A minimum rotational crop plant-back interval of 60 days must be observed for all food/feed crops not currently on the label.
• The number of applications on tomato per year to be reduced from 6 to 5.

Label improvements required to meet current standards:

• Additional improvements to the product labels are required to provide clarity in areas such as the use directions. For certain products registered for uses on livestock and livestock housing, label updates must include the supported use directions (application rate, maximum number of applications, minimum re-treat interval, and/or pre-slaughter interval) on product labels, where applicable.
• Additional improvements to the product labels are required for domestic- and commercial-class products used in residential areas.

Environment

To protect the environment, the following risk-reduction measures are required:

• Environmental hazard statements for bees, beneficial insects, birds and aquatic organisms
• To reduce risk to pollinators, application is restricted or prohibited during the crop blooming period for bee attractive crops.
• To reduce risk to beneficial insects living in habitats adjacent to the application site, spray drift should be minimized.
• Spray buffer zones for non-target aquatic habitats.
• To reduce the potential for run-off of permethrin to adjacent aquatic habitats; precautionary statements for sites with characteristics that may be conducive to runoff and when heavy rain is forecasted.
• Addition of a vegetative filter strip between the treatment area and the edge of a down-gradient water body to reduce runoff of permethrin to aquatic environments.

Next Steps

To comply with this decision, the required mitigation measures must be implemented on all product labels sold by registrants no later than 24 months after the publication date of this decision document (RVD2019-11). The registered products containing permethrin that are subject to this decision can be found through Health Canada’s online pesticide label search database. One registered product, Raid Fumigator Fumigating Fogger (Registration Number 25167) is cancelled by this decision. Raid Fumigator Fumigating Fogger will be phased out following the implementation timeline outlined below.

• One (1) year of sale by registrant from the publication date of this decision document, followed by;
• One (1) year of sale by retailer from the last date of sale by registrant, followed by;
• One (1) year of permitted use from the last date of sale by retailer.

Other Information

Any person may file a notice of objection^{Footnote 4} regarding this decision on permethrin within 60 days from the date of publication of this Re-evaluation Decision. 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 Pest Management Information Service by phone (1-800-267-6315) or by e-mail (pmra.info-arla@hc-sc.gc.ca).

The relevant test data on which the decision is based (as referenced in PRVD2017-18) 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.