Policy on continuous oversight of pesticides

Health Canada - Pest Management Regulatory Agency
14 October 2025
ISSN: 2819-6376 (PDF version)
Catalogue number: H113-32/1-2025E-PDF (PDF version)

Disclaimer

This administrative document does not constitute part of the Pest Control Products Act or its regulations and in the event of any inconsistency or conflict between the Act or regulations and this document, the Act or the regulations take precedence

Table of contents

• 1.0 Purpose
• 2.0 Background
• 3.0 Objective
• 4.0 Scientific information sources and monitoring
• 5.0 Triage of scientific literature and regulatory information
• 6.0 Application of continuous oversight information in supporting PMRA science assessments and decision making
• 7.0 Transparency and stakeholder engagement

1.0 Purpose

This document describes the Pest Management Regulatory Agency's (PMRA) continuous oversight policy for pesticides registered in Canada. It has been prepared taking into consideration comments provided during the 60-day public consultation period by interested stakeholders on the draft policy Regulatory Proposal PRO2024-01, Proposed policy on continuous oversight of pesticides, which was published on 3 January 2024.

2.0 Background

In Canada, pest control products, or pesticides, are regulated by the PMRA under the authority of the Pest Control Products Act.

The primary objective of the Pest Control Products Act is to prevent unacceptable risks to individuals and the environment from the use of pesticides. The Act prescribes both pre-market and post-market assessment of the human health and environmental risks and value of pesticides to determine the acceptability, or continued acceptability, in Canada.

The rapid generation of new scientific information on pesticides necessitates a systematic and predictable approach to monitoring emerging science over the lifecycle of a pesticide. As outlined within this policy, the PMRA is moving away from a point in time monitoring approach towards implementing a proactive and continuous oversight approach for monitoring scientific information sources. This will ensure that the PMRA stays abreast of emerging risks related to pesticides registered in Canada and prioritizes regulatory action when necessary to protect human health and the environment.

If at any time during the registration lifecycle the PMRA has reasonable grounds to believe that health or environmental risks, or the value, of a pesticide may no longer be acceptable, the PMRA evaluates the aspect of concern by initiating a special review. The special review considers the relevant information and may amend or cancel the registration if necessary to address the aspect of concern that prompted the special review. Full details related to special reviews can be found in the PMRA Guidance Document, Approach to Special Reviews of Pesticides.

In tandem with the implementation of continuous oversight, the PMRA is developing its proportional effort policy. Recognizing that some pesticides require more regulatory oversight than others, the objective of the proportional effort policy is to employ a systematic categorization process to ensure an appropriate level of review that is commensurate with the health and environmental risks of the pesticide. To be effective, the proportional effort approach must be dynamic, responding to new scientific evidence that may shift risk profiles over time. This is where the continuous oversight model plays a critical role. By systematically monitoring emerging science and other relevant information, continuous oversight ensures that the level of regulatory oversight assigned through proportional effort remains appropriate and evidence-based. Together these two policies are intended to create a balanced approach that optimizes regulatory resources while maintaining robust protection for human health and the environment.

To ensure seamless integration of the two policies, the PMRA will establish guidelines and processes that outline how continuous oversight findings may inform proportional effort determinations. This integration will enhance regulatory efficiency and transparency by prioritizing resources based on updated risk assessments. A gradual, multi-year phase-in of the new approaches will allow the PMRA to measure the effectiveness of these policies, and their impact including maturing supporting guidelines and processes over time.

3.0 Objective

The objective of the PMRA's continuous oversight policy is to enhance the PMRA's ability to protect human health and the environment in Canada by proactively monitoring and considering new scientific information related to the risk characterization of pesticides throughout the pesticide lifecycle, and taking appropriate regulatory action when necessary.

Implementation of continuous oversight increases the protection of human health and the environmental through:

• Systematic monitoring, collection and consideration of science information related to pesticides in Canada;
• Keeping pace with the evolving science of pesticides, including science literature and Indigenous knowledge;
• Triggering timely regulatory action, as necessary, in response to a newly identified aspect of concern with a registered pesticide; and
• Supporting the PMRA's science reviews and decision making with up-to-date science and regulatory information on pesticide active ingredients and associated products.

Continuous oversight is a complementary process that supports but does not replace requirements outlined in the Pest Control Products Act, including applications for registration, amendment, re-evaluation and special review. In its regulatory decisions, the PMRA considers the totality of available information including studies submitted by pesticide registrants, as well as publicly available scientific information collected through continuous oversight.

Continuous oversight starts upon the initial registration of a pesticide active ingredient and continues throughout its regulatory lifecycle. Relevant information collected and retained could support major reviews such as re-evaluations or special reviews or could trigger earlier regulatory action based on an emerging risk, ensuring that new information is being considered between, and during, review activities.

4.0 Scientific information sources and monitoring

There are four sources of information under continuous oversight:

• Pesticide incident reporting information,
• Pesticide water monitoring information,
• Chemistry information for technical grade active ingredient products, and
• Scientific literature and regulatory information.

The PMRA currently considers and incorporates these sources of information into review activities.

Under continuous oversight, this information will be collected in an expanded and more standardized and predictable manner, and on an ongoing basis throughout the pesticide's lifecycle. This allows for earlier identification of emerging risks and regulatory action when necessary.

The following Sections (4.1–4.4) describe the four sources of information and how they are considered.

4.1 Pesticide incident reporting information

The Pest Control Products Act requires registrants to report to the PMRA incidents of adverse effects that involve their registered pesticides. The Pest Control Products Incident Reporting Regulations specify the specific reporting requirements, including the types of information to be reported and the time frames for reporting the information. Registrants are required to report information concerning pesticide incidents that occur in Canada as well as a subset of more serious incidents that occur in the United States.

Incidents include effects on humans, domestic pets, plants and animals (both terrestrial and aquatic), as well as packaging failure that could result in exposure or injury to humans or the environment. Incident reports provide the PMRA with valuable real-world information regarding potential risks to humans or the environment from the use of registered pesticides.

Registrants are also required to provide the PMRA with any scientific study they have sponsored if it indicates either a new health or environmental hazard, increased health or environmental risk or the presence of a component or derivative that has not been previously detected. Registrants must report on a discontinued study or a study that is in progress, if the study has demonstrated adverse effects.

The Guidance for the Pest Control Products Incident Report Regulations provides details on how the PMRA monitors, considers and takes action based on information received through the incident reporting program.

4.2 Pesticide water monitoring information

The PMRA is establishing a long-term collaborative Canadian water monitoring program for pesticides and finalizing a framework to ensure consistency in data collected across Canada. Together with federal and provincial governments and local partners, the PMRA is collaborating to increase and enhance pesticide water monitoring in Canada.

Using data from all available sampling sources, the PMRA screens the detected concentrations of pesticides in water against Aquatic Life Reference Values (ALRV) and Human Health Reference Values (HHRV). Reference values are pesticide concentrations in water below which risks to aquatic life and human health are not expected. Where levels of a pesticide found in the Canadian environment exceed the reference values, the PMRA determines the appropriate regulatory action required.

4.3 Chemistry information for technical grade active ingredient products

The PMRA monitors product chemistry information for individual sources of technical grade active ingredients to ensure they are being manufactured consistent with the approved specifications and methods. Technical grade active ingredient products are used as the source material for formulating pesticide end-use products. Unreported and unverified changes to the manufacturing process or specifications of the active ingredient can have implications for the health or environmental risk assessment of the pesticide. Periodic monitoring of chemistry is important for ensuring that risk assessments are relying on the best available chemistry information.

Registrants of technical grade active ingredient products are required to submit updated chemistry information upon request for the PMRA to verify that the chemical composition has not changed and to check impurities against current standards. The PMRA maintains a transparent and predictable work plan through which chemistry verification for each active ingredient will occur at least every ten years, with the flexibility to allow for more frequent chemistry verification when required.

The PMRA memorandum to registrants, applicants and their representatives entitled "Verifying chemistry of registered technical grade active ingredients and integrated system products" provides detailed information on how the PMRA monitors the chemistry of pesticide active ingredients, and the process for addressing concerns when they arise.

4.4 Scientific literature and regulatory information

Through continuous oversight, the PMRA proactively monitors scientific literature and regulatory information for new findings related to human health or environmental risks of currently registered pesticides.

The types of scientific literature and regulatory information captured by continuous oversight activities include:

• Studies and reports from academic institutions and researchers published in peer-reviewed science journals related to pesticide exposure and/or risk characterization;
• Scientific grey literature, which includes science reviews, evaluations, monitoring, biomonitoring, risk assessments and regulatory documents related to pesticide exposure and/or risk characterization, from Canadian and international governments and public organizations, that are not published in traditional science journals; and
• Indigenous knowledge related to the effects of pesticides, where available.

5.0 Triage of scientific literature and regulatory information

The PMRA searches databases using standardized search criteria to identify and collect scientific literature related to pesticides and their effects. A streamlined and stepwise approach is then applied to triage the information to determine if the information is relevant, and what, if any, regulatory action is required. Additional details related to the search criteria, and the databases searched can be found in the PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information.

5.1 Screen for relevance

The scientific literature and regulatory information found through continuous oversight is screened to identify relevant information for further consideration. Screening for relevance is not a science review of the information and does not consider the results or quality of the information at this step.

Scientific literature and regulatory information is considered relevant in the context of continuous oversight provided that it meets all of the following criteria:

1. It relates to a pesticide that is registered in Canada. Information related to all pesticides registered in Canada can be found in the Pesticide Product Information Database of Health Canada's Public Registry for pesticides.
2. It applies to one or more use patterns that are registered in Canada. Use patterns associated with registered pesticides in Canada are defined by use-site categories and the specific crops or sites for which the pesticide is registered. Information related to use site categories for which pesticides are registered in Canada can be found in the Pesticide Product Information Database of Health Canada's Public Registry for pesticides.
3. It is applicable to the assessment and characterization of human health or environmental risk in Canada. Information used in the assessment of pesticides is categorized by a series of data codes (DACOs), which are described in DACO tables associated with different product types. Information that relates to the assessment and characterization of human health or environmental risk is included in DACOs 4-9. Information that does not directly impact or inform the risk assessment of the pesticide is not relevant in the context of continuous oversight. Examples include pesticide value information in DACO 10 (for example, efficacy, economic information, pesticide resistance, and agricultural production information).

Additional details related to how the criteria to determine relevance are applied to information collected under continuous oversight can be found in the PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information.

Scientific literature and regulatory information that does not meet all the above criteria for relevance is not considered further under continuous oversight, but it may still be used in other PMRA programs or activities. Relevant information continues through the triage to determine if action is required.

5.2 Determine if action is required

For information that is deemed relevant, the PMRA proceeds with determining what action, if any, may be warranted. This is aligned with the preliminary analysis for special reviews, as outlined in the PMRA Guidance Document, Approach to Special Reviews of Pesticides.

The relevant information is considered in the context of the PMRA's existing knowledge of the pesticide (for example, existing risk assessment conclusions, use information). Detailed criteria have been developed to quickly identify information that should be retained without additional triage, information that should not be considered further due to limitations that would preclude its use in a risk assessment, and information that should be further triaged. Additional details of these criteria and their application to scientific literature and regulatory information collected through continuous oversight can be found in the PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information.

For information that requires further triage, the PMRA compares the study's reported findings (for example, dose levels, toxicological effects, endpoints, exposure scenarios, numerical data) with the conclusions of the PMRA's existing risk assessment. This comparison allows the PMRA to determine if the study's findings indicate a potential aspect of concern that may trigger a change in the existing risk assessment conclusions and mitigation measures.

As described in the PMRA Guidance Document, Approach to Special Reviews of Pesticides, information that could alter the outcome of an existing risk assessment includes scientific results that indicate a greater hazard and potential for a lower toxicology reference value, a new risk (previously unidentified), or higher exposure levels than those previously considered by the PMRA. When investigating a potential aspect of concern, the PMRA considers the scientific validity and acceptability of the published scientific literature using the criteria and approaches outlined in the PMRA Information Note, Determining Study Acceptability for use in Pesticide Risk Assessments to determine whether information can be considered in support of a decision.

Relevant studies that do not indicate a potential aspect of concern are retained in PMRA's body of evidence for consideration during future pre- and post-market reviews, including future risk characterization, refinement of risk assessment methods and/or trend analysis. At this point in the triage, a study with a major limitation (for example, a study that does not identify the concentration of the test substance) will not be considered further.

5.3 Triage outcomes

When a piece of scientific literature or regulatory information collected through continuous oversight completes the triage process, one of four possible outcomes could apply. These outcomes, the associated actions and stakeholder notifications are described in this section. Examples to illustrate the type of information that could lead to each outcome are also provided.

Possible outcomes of the triage process and associated actions

Outcome 1: The information is not relevant or is excluded based on established criteria.

Action: No further action required.

Stakeholder Notification: Citation will be included in the transparency report for continuous oversight of scientific literature and regulatory information.

Examples:

• A study that does not contain information that can be used in the human health and/or environmental risk assessment.
• A study with major scientific limitations that cannot be used in a risk assessment.

Outcome 2: Information is relevant but no immediate action is required. Information is equivalent to, or already accounted for in, the existing risk assessment, and or the study or information does not indicate any new or increased risk relative to the current risk assessment.

Action: The information is retained as part of the body of evidence for future consideration should the risk assessment be updated, revised, or refined as part of a future application or evaluation. Key study information is captured to support subsequent use of the study by the PMRA (for example, study type, species, duration, effects).

Stakeholder Notification: Citation will be included in the transparency report for continuous oversight of scientific literature and regulatory information.

Examples:

• A study that describes an effect at a dose that is higher than the level already used in the PMRA risk assessment.
• A study that describes an effect that is already known and accounted for in the PMRA risk assessment.
• A study that potentially demonstrates a decrease in risk.
• A study that does not apply to the current route or duration of pesticide exposure as currently registered in Canada.

Outcome 3: The information does not meet the threshold to trigger a special review, but additional information is needed to further explore the science area.

Action: The PMRA issues a requirement for registrants to compile information, conduct tests or monitor the pesticide. Once information is received, it is reviewed and the PMRA determines if a special review is required. If the information is not required immediately to characterize risks, the PMRA provides early notification of anticipated data requirements for future pre-market submissions, or for the next re-evaluation.

Stakeholder Notification: Registrants are formally notified (as per process under section 12 of the Pest Control Products Act) and a public notice outlining the data required, the associated timeline and the reason(s) for the request is posted to the Public Registry. If the information is not required immediately, the updated data requirements are communicated in writing directly to the implicated registrants and an update is made in the Public Registry.

Examples:

• A study, or series of studies, shows an emerging area of risk but limitations in the study design(s) do not allow for full risk characterization. A new study is needed to fully characterize the risk.
• A study is identified in a review from an Organisation for Economic Co-operation and Development regulator that the PMRA has not previously considered. Based on the foreign review decision, the PMRA may determine that the study is not required immediately and may request it at the next re-evaluation to fully characterize the risk.

Outcome 4: The information provides reasonable grounds to believe that the health or environmental risks are unacceptable. The information indicates a serious possibility of an increase in risk or identifies a new health or environmental risk that may result in changes to the existing risk assessment, and changes to the conditions of registration may be required.

Action: The PMRA initiates a special review to conduct a full review of the study or information for the aspect of concern.^{Footnote 1}

Stakeholder Notification: As per the PMRA Guidance Document, Approach to Special Reviews of Pesticides, registrants are formally notified of the initiation and a public notice outlining the aspects of concern, including appropriate regulatory context, and any additional data that are required is posted to the Public Registry. Upon completion of the review, the PMRA issues a proposed special review decision for public consultation outlining the results of that review and any proposed mitigation measures required.

Example:

• A study that suggests the pesticide is more toxic than was considered in the PMRA's risk assessment that might impact risk conclusion and require changes to the product label.

5.4 Performance standard

To support the efficient and timely consideration of new scientific literature and regulatory information collected through continuous oversight, the PMRA commits to a performance standard of a maximum of 180 days from identification of the new science information to a triage outcome, 90% of the time. This performance standard is monitored through the initial implementation of continuous oversight and may be adjusted if required.

6.0 Application of continuous oversight information in supporting PMRA science assessments and decision making

The PMRA currently considers information collected through incident reporting, water monitoring, chemistry verification and scientific and regulatory information in its regulatory decisions. This policy brings together all four sources of scientific information under continuous oversight and outlines the standardized processes to how this information, particularly the scientific and regulatory information, is monitored, collected and considered on an ongoing basis throughout the lifecycle of an active ingredient so that the relevant information is readily available for consideration.

Information collected through continuous oversight that does not require immediate regulatory action is retained in the body of evidence and available for consideration in future reviews. A determination as to whether the relevant scientific information should be considered in the review will depend on the nature of the application as well as the need for the information to conduct, update or refine the risk assessment and determine the risk acceptability. The relevant information is considered in the context of the PMRA's existing knowledge of the pesticide (for example, existing risk assessment conclusions, use information) and the body of evidence retained through continuous oversight. The PMRA considers where groups of studies or information may over time identify potential aspects of concern when considered collectively.

While the collection of information through incident reporting and chemistry verification is fully implemented, a water monitoring pilot program has been completed and a framework for a national pesticide water monitoring program is being developed. The collection and triage of scientific and regulatory information will be phased in over time. The approach to this is described in the PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information and includes considerations related to criteria to determine which pesticides will be included in searches of the published scientific literature, and when, criteria and processes to search for grey literature and Indigenous knowledge, and how this information will be integrated into risk assessments.

As required by the Pest Control Products Act, registrants are given a reasonable opportunity to make representations in respect of any additional information that the PMRA used in its review that the registrant did not submit, including information collected through continuous oversight, before the evaluation is completed.

If through continuous oversight the PMRA identifies additional data requirements for future applications or future re-evaluations, the PMRA will communicate these requirements directly to the implicated registrants in writing and provide an update in the Public Registry.

7.0 Transparency and stakeholder engagement

The PMRA is committed to transparency in the processes, findings and outcomes of continuous oversight and will include summary information in its annual reports. More detailed information is shared publicly on an ongoing basis through the documents and websites described below:

• Information related to incident reports can be accessed through the Pesticide Incident Reporting Database.
• Water monitoring data can be accessed through the open data portal for the National Water Monitoring Program for Pesticides.
• Details related to the verification of chemistry information for technical grade active ingredient products, and the associated 5-year workplan are found on the Government of Canada website, Canada.ca.
• The PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information contains descriptions of the processes and criteria used to collect and triage information, and to determine if action is required.
• The PMRA will make available transparency reports for scientific literature and regulatory information collected through continuous oversight. The PMRA Information Note, Continuous Oversight of Scientific Literature and Regulatory Information contains details related to the content of these reports.

As per existing PMRA policies, when a special review is initiated, or where a requirement is imposed on registrants, the registrants are formally notified and a notice is posted to the Public Registry outlining, as applicable, the action taken, requirements the registrant must fulfill and the associated timelines.

As the PMRA considers new scientific information through continuous oversight, new insights can emerge that do not necessarily result in additional regulatory action yet may be important considerations for future submissions or re-evaluations. When new information has been identified that may be important for future consideration, the PMRA will notify implicated registrants as soon as it has been identified. This will allow the registrants an opportunity to assess the findings and, if required, prepare or generate data or scientific rationales to address the information.

Stakeholders will continue to be engaged as processes related to continuous oversight are implemented and refined. Transparency initiatives will continue to be enhanced based on public needs, feedback from stakeholders and as information technology tools are developed. In the interim, the PMRA will respond to active ingredient-specific inquiries related to continuous oversight via the Pest Management Information Service. Applicants and registrants are encouraged to continue directing inquiries relating to future premarket applications by requesting a pre-submission consultation.