Re-evaluation Decision RVD2025-09, Cellulose (from powdered corn cobs) and its associated end-use products

Pest Management Regulatory Agency
19 November 2025
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2025-9E-PDF (PDF version)

Summary

Table of contents

• Re-evaluation decision for cellulose and associated end-use products
• Re-evaluation decision for cellulose
• Risk mitigation measures
• Label amendments
• Implementation of the re-evaluation decision
• Next steps
• Other Information
• Appendix I  Registered products containing cellulose in Canada

Re-evaluation decision for cellulose and associated end-use products

Under the authority of the Pest Control Products Act, all registered pesticides must be re-evaluated by Health Canada’s Pest Management Regulatory Agency (PMRA) to ensure that they meet current health and environmental standards and have value. The re-evaluation considers information from various sources such as data and information from pesticide manufacturers 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 risk management approaches and policies.

This document (Re-evaluation Decision RVD2025-09, Cellulose (from powdered corn cobs) and its associated end-use products) presents the final re-evaluation decision^{Footnote 1} for the re-evaluation of cellulose (from powdered corn cobs), including the response to comments received, and the required label updates. All products containing cellulose regulated under the Pest Control Products Act in Canada are subject to this re-evaluation decision.

Cellulose is a rodenticide prepared from powdered corn cobs which interferes with the digestive system of rats and mice. There are currently six domestic class end-use products registered for the control of rats and mice indoors. Similarly, the commercial class end-use product is registered for indoor use in buildings, warehouses, barns, and empty feed storage areas. All end-use products are formulated as pellets (bulk pellets, pellets in pre-measured ready-to-use place packs, or pellets in pre-measured ready-to-use bait trays).

Currently registered products containing cellulose can be found in the Pesticide Product Information Database and in Appendix I. The Proposed Re-evaluation Decision PRVD2025-04, Cellulose (from powdered corn cobs) and its Associated End-use Products^{Footnote 2} containing the evaluation of cellulose and the proposed decision, underwent a 90 day consultation period ending on 1 June 2025. PRVD2025-04 proposed continued registration of cellulose products in Canada, with updates to label directions and precautions to reflect the current labelling standards and to improve clarity (Appendix IV of the full version of RVD2025-09).

Health Canada received comments during the public consultation. Commenters are listed in Appendix II of RVD2025-09. The comments are summarized in Appendix III of RVD2025-09 along with the responses by Health Canada. The comments did not result in changes to the proposed re-evaluation decision as described in PRVD2025-04. A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2025-04.

Re-evaluation decision for cellulose

Health Canada has completed the re-evaluation of cellulose. 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 cellulose is required to be amended, in accordance with paragraph 21(2)(a) of the Pest Control Products Act. An evaluation of available scientific information related to human health and environmental risks and value of cellulose found that all uses of cellulose products meet current standards for protection of human health and the environment and have acceptable value when used according to the amended conditions of registration which includes updates to standard label statements to reflect the current labelling standards and for clarity. Label amendments, as summarized below and listed in Appendix IV of RVD2025-09, 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 updated label statements, as a result of the re-evaluation of cellulose, are summarized below. Refer to Appendix IV of RVD2025-09 for details.

Label amendments - Human health

• Update labels (Principal Display Panel, precautions, use limitations, storage) to minimize the exposure of cellulose to pets and people during its use and storage.
• Update labels of commercial and domestic end-use products to indicate that individuals should avoid inhaling dust generated by handling of the end-use products, for consistency.

Label amendments - Environment

• Update labels to reflect current standards.

Label amendments - Value

• Update general statements on all product labels to improve clarity and meet current standards (for example, replace “guarantee” with “active ingredient”).

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). 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 (label updates) for pest control products containing cellulose is considered acceptable. These required amendments must be implemented within 24 months after the publication date of this decision document.

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 this decision document. Accordingly, both registrants and retailers will have up to 24 months from the date of this decision document 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 this decision document 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

Any person may file a notice of objection^{Footnote 3} regarding this decision on cellulose and its associated end-use products 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 and pest management Section of the Canada.ca website (Public Engagement Portal - Public Engagement Portal forms - Notice of Objection) or contact PMRA’s Pest Management Information Service.

The relevant confidential test data on which the decision is based (as referenced in PRVD2025-04) are available for public inspection, upon application, in PMRA’s Reading Room. For more information, please contact the PMRA’s Pest Management Information Service.

Appendix I Registered products containing cellulose in Canada

Table 1 Products containing cellulose requiring (label) amendments^{Footnote 1}

Registration number	Marketing classFootnote 2	Registrant	Product name	Formulation type	Active ingredient (%, g/L)
28682	T	Verdesian Life Sciences U.S., LLC	Rode-trol Rodent Control Bait Technical Grade Active Ingredient	Dust or Powder	45%
32657	T	ConSeal International, Inc.	RatX Technical	Solid	29.3%
29978	M	Verdesian Life Sciences U.S., LLC	Rode-trol Rodent Control Bait for Mice and Rats MUP	Pellets	42.75%
28684	C	Verdesian Life Sciences U.S., LLC	Rode-trol Rodent Control Bait for Mice and Rats	Pellets	42.75%
28916	D	Verdesian Life Sciences U.S., LLC	Rode-trol Rodent Control Bait for Mice and Rats – Domestic	Pellets	42.75%
29427	D	Premier Tech Ltd.	Wilson Mouse Out Rat and Mouse Killer Pellets	Pellets	42.75%
32658	D	ConSeal International, Inc.	RatRid Rat & Mouse Killer Pellets	Pellets	27.5%
33437	D	ConSeal International, Inc.	RatRid Ready-to-Use	Pellets	27.5%
33658	D	ConSeal International, Inc.	MouseRid Rat & Mouse Killer Pellets	Pellets	27.5%
33856	D	ConSeal International, Inc.	MouseRid Ready-to-Use	Pellets	27.5%