Re-evaluation Decision RVD2026-04, Potassium bicarbonate and its associated end-use products

Health Canada
Healthy Environments and Consumer Safety Branch
Pesticides Regulatory Directorate
4 August 2026
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2026-4E-PDF (PDF version)

Summary

Table of contents

• Re-evaluation decision for potassium bicarbonate and associated end-use products
• Re-evaluation decision for potassium bicarbonate
• Risk mitigation measures
• Implementation of the re-evaluation decision
• Amendment timeframe
• Next steps
• Other information
• Appendix I  Registered products containing potassium bicarbonate in Canada

Re-evaluation decision for potassium bicarbonate and associated end-use products

Under the authority of the Pest Control Products Act, all registered pesticides must be re-evaluated by Health Canada to ensure that they meet current health and environmental standards and have value. The re-evaluation considers data and information from pesticide manufacturers, incident reports and other regulatory agencies, as well as comments directly related to the proposed re-evaluation decision, such as comments directed to the Science evaluation, received during public consultations. Health Canada applies internationally accepted risk assessment methods as well as current risk management approaches and policies. More details, on the legislative framework, risk assessment and risk management approach, are provided under the Evaluation Approach of the full version of Re-evaluation DecisionRVD2026-04, Potassium Bicarbonate and its associated end-use products.

Potassium bicarbonate is a contact fungicide that acts by inhibiting fungus mycelium development following spore germination. Potassium bicarbonate is registered for control or suppression of powdery mildew on a wide range of greenhouse and field crops including certain ornamentals, vegetables, fruits, herbs and spices, cannabis grown in greenhouses or other enclosed growing structures and field-grown cannabis and industrial hemp. It is also registered for suppression of Botrytis grey mold on grapes and partial suppression of primary infections of apple scab in orchards. Currently registered products containing potassium bicarbonate can be found in the Pesticide Product Information Database and in Appendix I.

The Proposed Re-evaluation Decision PRVD2025-06, Potassium Bicarbonate^{Footnote 1} containing the evaluation of potassium bicarbonate and proposed decision, underwent a 90-day consultation period ending on 8 September 2025. PRVD2025-06 proposed continued registration of potassium bicarbonate and all associated end-use products in Canada, with updates to label directions and precautions to reflect the current labelling standards and improve clarity (Appendix II of PRVD2025-06). Risk mitigation measures included a drift statement for all commercial class end-use product labels to minimize potential for spray drift to residential areas, and updates to precautionary label statements as per current labelling standards such as PPE, restricted-entry interval, storage and disposal.

Written comments were received during the public consultation period conducted in accordance with section 28 of the Pest Control Products Act. However, they did not relate to the health, environmental or value assessments in PRVD2025-06. Therefore, this decision is consistent with the proposed re-evaluation decision as described in PRVD2025-06. In addition, is it to be noted that the registrant already voluntarily implemented the limitation of the application of potassium bicarbonate for use on cannabis grown in greenhouses, other enclosed growing structures and grown outdoors during the vegetative stage only in response to the publications of Health Canada’s guidance document (July 2025), Classification Of Cannabis and Industrial Hemp Crops as Use Sites, Data Requirements and Label Amendments.

A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2025-06; no further information was used in the final re-evaluation decision. Therefore, the complete reference list of all information used in this final re-evaluation decision is set out in PRVD2025-06.

This document (RVD2026-04) presents the final re-evaluation decision^{Footnote 2} for the re-evaluation of potassium bicarbonate, including the required amendments (risk mitigation measures) to protect human health and the environment, as well as label amendments required to bring labels to current standards. All products containing potassium bicarbonate that are registered in Canada are subject to this re-evaluation decision.

Re-evaluation decision for potassium bicarbonate

Health Canada has completed the re-evaluation of potassium bicarbonate. Under the authority of the Pest Control Products Act, Health Canada has completed all required evaluations and consultations and has determined that the registration of products containing potassium bicarbonate is required to be amended, in accordance with paragraph 21(2)(a) of the Pest Control Products Act. An evaluation of available scientific information respecting the health and environmental risks and value of potassium bicarbonate found that all uses of potassium bicarbonate products meets current standards for protection of human health and the environment and has acceptable value when used according to the amended conditions of registration which includes new mitigation measures. Label amendments, as summarized and listed in Appendix II of RVD2026-04, 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 mitigation measures, as a result of the re-evaluation of potassium bicarbonate. Refer to Appendix II of RVD2026-04 for details.

Human health

Label improvements to meet current standards:

Risk mitigation:

To protect workers and those entering treated areas from exposure, the following risk-reduction measures are required for continued registration of potassium bicarbonate in Canada:

• Update personal protective equipment, restricted-entry interval, and spray drift statement to meet current standards. 
• Update precautionary statements to include respirator and ventilation requirements for all the labelled crops treated in enclosed areas using ultra-low volume method of application. 

Environment

Label improvements to meet current standards:

Risk mitigation:

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

• Label amendments to meet current standards including disposal statement and use directions (spray drift).

Implementation of the re-evaluation decision

Regulatory Directive DIR2018-01, Policy on Cancellations and Amendments Following Re-evaluation and Special Review provides information and general timelines regarding the implementation of post-market decisions, (for example, up to 24-month timeline for label amendments and up to 36-month phase-out timeline for cancelled registrations), and Information Note: Update on implementation of post-market decisions provides additional information on phase-out measures for post-market decisions that include cancellations. The post-market decision considers potential health and environmental risks regarding the use of the pest control product, and its value, when establishing the implementation timelines.

Amendment timeframe

The implementation timeline of 24 months for the required amendments (mitigation measures and label updates) for pest control products containing potassium bicarbonate is considered acceptable. These required amendments must be implemented within 24 months after the publication date of PRVD2026-04. 
Refer to Appendix I for details on specific products impacted by this decision.

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 RVD2026-04. Accordingly, both registrants and retailers will have up to 24 months from the date of RVD2026-04 to transition to selling the product with the newly amended labels. Similarly, users will also have the same 24-month period from the date of RVD2026-04 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

The relevant confidential test data on which the decision is based (as referenced in PRVD2025-06) are available for public inspection, upon application, in the Pesticides Regulatory Directorate’s Reading Room. For more information, please contact the Pesticides Information Service.

Any person may file a notice of objection^{Footnote 3}, which must be based on scientific grounds, regarding this decision on potassium bicarbonate and its associated end-use products within 60 days from the date of publication of this Re-evaluation Decision through the Public Engagement Portal (Public Engagement Forms - Notice of Objection). The request for reconsideration must include the Notice of Objection form, the scientific explanation of the objection and the supporting scientific evidence in possession of the requestor that would not already be in the Health Canada’s possession or cite specific Health Canada documentation they wish to rely on as supporting evidence (for example, scientific reports) in the form of electronic copies of cited references. Each of the references provided or cited must be clearly associated with the objection it supports. Failure to provide a complete package may result in the Notice of Objection being considered ineligible for further consideration by Health Canada. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides and Pest Management portion of the Canada.ca website or contact the Pesticides Information Service.

Appendix I Registered products containing potassium bicarbonate in Canada