Proposed Re-evaluation Decision PRVD2020-08, Pyrethrins and Associated End-use Products
Pest Management Regulatory Agency
17 September 2020
ISSN: 1925-0967 (PDF version)
Catalogue number: H113-27/2020-8E-PDF (PDF version)
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Table of contents
- Proposed re-evaluation decision
- Outcome of science evaluation
- Proposed regulatory decision for pyrethrins
- Proposed risk mitigation measures for pyrethrins
- International context
- Next steps
- Additional scientific information
Proposed 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. Health Canada applies internationally accepted risk assessment methods as well as current risk management approaches and policies.
Pyrethrins are insecticides registered for use on a wide range of commercial and domestic sites including agricultural crops, greenhouses, livestock, companion animals, structural sites (indoor and outdoor), clothing, and stored grains. Pyrethrins products are available in various formulations, including dusts, solutions, emulsifiable concentrates, pastes, solids (coils) and pressurized products. A list of the registered products containing pyrethrins in Canada can be accessed through the PMRA’s label transcription service.Footnote 1
Many pyrethrins-containing products were registered prior to the development of modern standardized label language and do not contain comprehensive use directions. Considering the very large amount of pyrethrins products currently registered and the variability with regards to the description of their uses on the labels, pesticide registrants and various stakeholders were consulted on several occasions throughout the re-evaluation process to gather additional information and clarifications on the use pattern of pyrethrins products. Limited information was obtained from theses consultations.
Therefore, a scenario-based approach was used to identify the pyrethrins use pattern, rather than a label-based approach. High-level use pattern summary tables were prepared that outlined the different use scenarios for pyrethrins. These tables were shared with registrants and user groups for consultation on the use pattern that was assessed for the re-evaluation. Clarifications were received which were incorporated into the summary tables.
As a result of this consultation, it was determined that the food uses assessed in the dietary assessment would be limited to the crops and uses specifically identified on commercial class pyrethrins labels, namely greenhouse peppers, blueberry, grape, raspberry, herbs, spices, pears, pinto, snap and wax beans, tomato, stored grains, the direct treatment of livestock, and the use in food handling establishments. In addition, uses where no data was available, such as some indoor or outdoor application methods for residential applicators, were not included in the assessment. Summary tables of the uses at the basis of the risk assessment can be found in Appendix I of PRVD2020-08.
This document (Proposed Re-evaluation Decision PRVD2020-08, Pyrethrins and Associated End-use Products) presents the proposed regulatory decision for the re-evaluation of pyrethrins including the proposed risk mitigation measures to further protect human health and the environment, as well as the science evaluation on which the proposed decision was based. All products containing pyrethrins registered in Canada are subject to this proposed re-evaluation decision. PRVD2020-08 is subject to a 90-day public consultation period, during which the public including the pesticide manufacturers and stakeholders may submit written comments and additional information to the PMRA. The final re-evaluation decision will be published taking into consideration the comments and information received.
Outcome of science evaluation
Pyrethrins are insecticides registered for use on a wide range of commercial and domestic sites including agricultural crops, greenhouses, livestock, companion animals, structural sites (indoor and outdoor), clothing, and stored grains.
With respect to human health, risks have been shown to be acceptable with mitigation measures required for most uses. However, dietary risks that have not been shown to be acceptable for the use on stored cereal grains. In addition, the risk from the use of domestic-class products used as indoor aerosol space sprays (including total release foggers) were not shown to be acceptable. Also, there were no data available to assess indoor or outdoor application using a mechanically-pressurized handheld sprayer for mists, aerosols, and fogs for residential handlers. Therefore, label directions are proposed to prohibit application using this type of equipment. Exposure from the remaining uses is unlikely to affect human health when used according to the proposed label directions, which include increased personal protective equipment (PPE) and a reduction in the amount handled per day for commercial-class products.
Pyrethrins enter the environment when used to control insects in a variety of agricultural crops, mosquito control uses and outdoor domestic uses. Based on available scientific information, potential risks to the environment have been shown to be acceptable when pyrethrins are used according to the proposed label directions.
Proposed regulatory decision for pyrethrins
Under the authority of the Pest Control Products Act and based on the evaluation of currently available scientific information, Health Canada is proposing that products containing pyrethrins are acceptable for continued registration in Canada, provided that the additional proposed risk mitigation measures are in place to further protect human health and the environment.
The use on stored cereal grains, where risks to human health are not shown to be acceptable is being proposed for cancellation. In addition, some indoor or outdoor application methods for residential applicators are proposed for cancellation due to the lack of data to assess their risks to human health. Furthermore, only the uses explicitly identified in the summary tables outlined in Appendix I of PRVD2020-08 were included in the risk assessment. All other uses are proposed for cancellation due to lack of data.
Registered pesticide product labels include specific directions for use. Directions include risk mitigation measures to protect human health and the environment that must be followed by law. As a result of the re-evaluation of pyrethrins, Health Canada is proposing further risk-reduction measures in addition to those already included on pyrethrins product labels. Additional revisions to the pyrethrins labels are proposed to update label statements to current policies and language.
Proposed risk mitigation measures
The updated label statements and mitigation measures required, as a result of the re-evaluation of pyrethrins, are summarized below. Refer to Appendix IX of PRVD2020-08 for details.
The following requirements are proposed to reduce potential exposure to workers using pyrethrins for agricultural uses:
- For application to agricultural crops using a mechanically-pressurized handgun, wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks, shoes, and a respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides, or a NIOSH-approved canister approved for pesticides during mixing, loading, application, clean-up and repair.
- For application using handheld airblast/mistblower, wear chemical-resistant coveralls over long-sleeved shirt, long pants, chemical-resistant hood, socks, chemical-resistant footwear, and a respirator with a NIOSH-approved organic-vapour removing cartridge with a prefilter approved for pesticides OR a NIOSH-approved canister approved for pesticides.
- When entering treated indoor areas prior to venting after application using a fogger (handheld airblast/mistblower or automatic fogger), wear chemical-resistant coveralls over long-sleeved shirt, long pants, chemical-resistant hood, chemical-resistant footwear, socks, chemical-resistant gloves, and a respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides OR a NIOSH-approved canister approved for pesticides.
- Restriction on the amount handled per day when applying using a handheld airblast/mistblower.
The following requirements are proposed to reduce potential exposure to workers using pyrethrins for non-agricultural/structural uses:
- For application using a mechanically-pressurized handgun, wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks, shoes, and a respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides, or a NIOSH-approved canister approved for pesticides during mixing, loading, application, clean-up and repair.
- For application using mechanically-pressurized handheld sprayer for mists, aerosols, and fogs, wear chemical-resistant coveralls over long-sleeved shirt, long pants, chemical-resistant hood, socks, chemical-resistant footwear, and a respirator with a NIOSH-approved organic-vapour removing cartridge with a prefilter approved for pesticides OR a NIOSH-approved canister approved for pesticides.
- For mixing, loading, and application using all dust application equipment, wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks, shoes, and a NIOSH approved N95 (minimum) filtering facepiece respirator (dust mask).
- When entering treated indoor areas prior to venting after applying using a fogger (total release fogger, mechanically-pressurized handheld sprayer for mists, aerosols, and fogs, and automatic fogger), wear chemical-resistant coveralls over long-sleeved shirt, long pants, chemical-resistant hood, chemical-resistant footwear, socks, chemical-resistant gloves, and a respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides OR a NIOSH-approved canister approved for pesticides.
- Restriction on the amount handled per day when applying using mechanically-pressurized handheld sprayer for mists, aerosols, and fogs in indoor scenarios.
- Restrictions on applications to golf course greens, fairways, and tees.
- Restriction on amount applied as a space spray in indoor residential sites.
- A label statement prohibiting use of domestic-class greenhouse end-use products in commercial greenhouses.
- A 2-hour re-entry interval is required after indoor residential space spray applications.
- Structural labels are to be updated as per the 2020 PMRA Guidance Document: Structural Pest Control Products: Label Updates.
The following mitigation measures are proposed to reduce exposure to residential handlers and residential postapplication exposure from domestic-class end-use products and from commercial class end-use products used in residential areas:
- For surface spray applications, label directions must be added or revised to:
- Specify the pests controlled, the application rate and application type (for example, perimeter/spot, crack and crevice) that was shown to have acceptable risk in the human health risk assessment. The maximum assessed rates are presented in Appendix I of PRVD2020-08.
- The revised label directions must clearly define and establish the conditions of use for residential areas where children may be present versus non-residential areas where children are not expected to be present.
- For products that are co-formulated with piperonyl butoxide, the acceptable application rates of piperonyl butoxide are presented in PRVD2020-09, Appendix IX, Sections 3.2 and 3.3. Co-formulated products must meet the mitigation requirements for both pyrethrins and piperonyl butoxide.
- Prohibit application using mechanically-pressurized handheld equipment for mists, aerosols, and fogs.
- Cancel the use of total release foggers including all domestic-class end-use products that have the “lock-valve” option.
- Prohibit the use of aerosol indoor space sprays (not including metered release devices).
To protect food safety and the health of Canadians, the following measures are proposed:
- Cancel the use of pyrethrins on stored grains
- Revoke the MRL of 3 ppm on raw cereals
- Establish a plant-back interval (PBI) of 12 months for all crops other than the ones for which pyrethrins is registered for use.
To protect the environment, the following risk mitigation measures are proposed:
- Standard environmental hazard statements to inform users of the potential toxic effects on bees, beneficial insects, birds and aquatic organisms.
- Prohibition or restriction of application during crop blooming period to protect pollinators.
- Label directions to minimise spray drift to reduce risk to beneficial insects living in habitats adjacent to the application site.
- Spray buffer zones for non-target aquatic habitats.
- Precautionary statements for sites with characteristics that may be conducive to run-off and when heavy rain is forecasted, in order to reduce the potential for run-off of pyrethrins to adjacent aquatic habitats.
Uses not included in the assessment and proposed for cancellation due to lack of data:
The following crops appear on domestic product labels but were not assessed:
- Apple tree, “fruit” tree (except pear)
- Outdoor and greenhouse applications to asparagus, beets, broccoli, Brussels sprout, cabbage, carrots, cauliflower, celery, cole crops, collards, cranberries, cucumbers, eggplant, kale, lettuce, mustard green, onion, pea, potato, radish, spinach, squash, turnip, “vegetables” (except crops specifically identified on commercial class pyrethrins labels), and vine products
- Outdoor application to peppers
- Greenhouse application to beans, herbs, tomatoes, “Greenhouse plantings” (except peppers)
- Label claims related to killing lice on mattresses, bedding, furniture, and garments are proposed for cancellation.
The proposed label amendments are listed in Section 8.0 and Appendix IX of PRVD2020-08.
Kresoxim-methyl is currently acceptable for use in other Organisation for Economic Co-operation and Development (OECD) member countries, including Australia, European Union, Japan, New Zealand and the United States. No decision by an OECD member country to prohibit all uses of pyrethrins for health or environmental reasons has been identified.
The public, including the registrants and other stakeholders are encouraged to submit additional information that could be used to refine risk assessments during the 90-day public consultation periodFootnote 2 upon publication of this proposed re-evaluation decision.
All comments received during the 90-day public consultation period will be taken into consideration in preparation of re-evaluation decision document,Footnote 3 which could result in revised risk mitigation measures. The re-evaluation decision document will include the final re-evaluation decision, the reasons for it and a summary of comments received on the proposed re-evaluation decision with Health Canada’s responses.
Additional scientific information
Data are required to confirm that the application rates and use directions on current product labels are consistent with the rates used in the residential, bystander and occupational risk assessments. Many current labels do not have any rate specified, or the rate is presented in a form that cannot be used for risk assessment purposes (for example, spray for 5 seconds). Registrants are required to provide data that bridges the use directions and/or the rate on the label, to a rate that can be expressed in units of the amount of pyrethrins per surface area (for example, mg a.i./cm2) for surface applications, or amount of pyrethrins per air volume (for example, mg a.i./m3) for space spray or fogging applications. Data are required for the following products:
- All ready-to-use, commercial-class products for all formulations (for example, pressurized products, dusts) used for structural pest control, unless current label directions have very clear application directions and rates.
- All domestic-class products for all formulations (for example, pressurized products, dusts) for all uses, except pet/livestock and greenhouse uses.
In addition, for several uses where risks were shown to be acceptable at the highest rate assessed, limited label rate use/directions are available. Consequently, additional label information is required to support the risk assessment proposal, and further confirm what use directions/mitigation will be required in the final re-evaluation decision.
Registrants are encouraged to contact the PMRA for guidance on how to meet this data requirement. Only products supported by data demonstrating that the rates used in the risk assessments are not exceeded will be considered for continued registration. A Notice, pursuant to paragraph 19(1)(a) of the Pest Control Products Act, will be issued to affected registrants in the near future and will include additional guidance on how to satisfy this data requirement.
In addition, although not required, for uses proposed for cancellation, Health Canada is asking stakeholders to provide information on how pyrethrins are typically used, including application rates, frequency of applications, minimum re-application interval, and maximum number of applications per year.
For uses where changes to the use pattern are proposed as mitigation measures, Health Canada is asking stakeholders to comment on the feasibility of the proposed changes, and the potential impact on the associated pest management practice.
- Footnote 1
The PMRA’s pesticide label search database is available online in the Pesticides portion of Canada.ca. Pesticide labels can also be accessed on a mobile device using the pesticide label app available in the Pesticides portion of Canada.ca.
- Footnote 2
“Consultation statement” as required by subsection 28(2) of the Pest Control Products Act.
- Footnote 3
“Decision statement” as required by subsection 28(5) of the Pest Control Products Act.
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