Information note regarding dsRNA-based pesticides

Organization: Health Canada

Date published: 4 January 2024

Cat.: H113-21/2023-1E-PDF

ISBN: 978-0-660-69246-3

Pest Management Regulatory Agency

4 January 2024

Table of Contents

• About dsRNA
• Current uses
• Current regulatory status
• Current actions
• For more information

The purpose of this information note is to communicate the current regulatory status of double-stranded ribonucleic acid (dsRNA)-based pesticides, and the current approach to their regulation under the Pest Control Products Act by Health Canada's Pest Management Regulatory Agency (PMRA).

About dsRNA

dsRNA is part of a process called RNA interference (RNAi) that occurs naturally in plants, animals and fungi. In RNAi, dsRNA molecules moderate gene expression by binding to a matching sequence of a "target" messenger RNA (mRNA), causing it to be destroyed. In other words, dsRNA transiently "silences" the expression of genes. This process can be harnessed for use in pest control applications by designing sequence-specific dsRNA to target mRNA encoding, for example, a protein that may be essential for the survival, reproduction, or growth of a pest. It could also be used to eliminate proteins that contribute to a pest exhibiting resistance to a conventional pest control product.

Current uses

Novel foods harnessing RNAi (for example, corn expressing a dsRNA that causes death in Western Corn Rootworm) have already been approved for use in food and feed by Health Canada's Health Products and Food Branch and by the Canadian Food Inspection Agency, respectively. However, dsRNA-based pesticides would differ from these novel foods in that dsRNA molecules would be applied directly to the crop (for example, by spraying), instead of the crop itself producing the dsRNA.

Current regulatory status

dsRNA-based pesticides are an active field of research and development, and applications for registration of dsRNA-based pesticides are expected in Canada. Health Canada's PMRA has completed pre-submission consultations and has been granting research authorizations for experimental trials of dsRNA-based pesticides since 2016. For more information on research involving dsRNA-based pesticides, please contact the PMRA's Pest Management Information Service.

The use of dsRNA in pest control applications meets the Pest Control Products Act definition of "pest control product", and therefore is subject to regulation by the PMRA as a novel class of pesticides. dsRNA does not fall under any of the existing frameworks for conventional or microbial active ingredients, pheromones or semiochemicals, etc.; therefore, data requirements for dsRNA-based pesticides are currently being determined on a case-by-case basis.

To date, the PMRA has not received any applications with data to support the registration of dsRNA-based pest control products. Sufficient data to assess any potential hazards and risks associated with dsRNA-based pesticides, such as data on toxicology, occupational and dietary exposure and hazard to non-target organisms in the environment, as well as their value, would need to be evaluated by the PMRA to determine if registration of such products could be approved.

Until such data are submitted and assessed, the use of dsRNA-based pesticides is not permitted under the Pest Control Products Act, except for research that has been approved by the PMRA under a research authorization.

Current actions

In anticipation of data development, the PMRA is working with international partners and stakeholders through the Organisation for Economic Co-Operation and Development (OECD) within the Ad Hoc Expert Group on RNAi-based Pesticides. This OECD Expert Group has developed documents on topics to consider in order to determine if risks associated with the use of dsRNA-based pesticides will be acceptable for human health and the environment.

In addition, the PMRA offers a free pre-submission consultation service that provides regulatory guidance to applicants prior to the submission of an application. To request a pre-submission consultation or to obtain additional information on submitting an application relating to a dsRNA-based pest control product, contact the PMRA at pmra.presubs-prealables@hc-sc.gc.ca.

For more information

• Pesticides in Canada
• Registrants and Applicants
• Research Authorizations and Notifications
• Pest Management Information Service
• OECD Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides and Biotechnology, Series on Pesticides No. 104 - Considerations for the Environmental Risk Assessment of the Application of Sprayed or Externally Applied dsRNA-Based Pesticides
• OECD Chemicals and Biotechnology Committee, Series on Pesticides No. 110 - Considerations for the Human Health Risk Assessment of Externally Applied dsRNA-Based Pesticides