Re-evaluation Note REV2013-02, Re-evaluation Update 2,4-D

Pest Management Regulatory Agency
10 July 2013
ISSN: 1925-0649 (PDF version)
Catalogue number: H113-5/2013-2E-PDF (PDF version)

The purpose of this document is to provide an update to registrants, pesticide regulatory officials and the Canadian public on Health Canada's Pest Management Regulatory Agency's (PMRA) review outcome regarding confirmatory scientific information on 2,4-D. Information was required from registrants as a result of the re-evaluation decision of 2,4-D completed in May 2008.Footnote 1 This information was requested under section 12 of the  Pest Control Products Act and included the following requirements:

  • Chemistry - Recent analytical data for all identifiable dioxins and furans from at least five consecutive batches of technical grade product manufactured at each of the registered manufacturing sites of each of the registered technical products.
  • Toxicology - A multigeneration reproduction study and a developmental neurotoxicity study in rats using 2,4-D acid complete with adequate histopathological examination of myelin desposition.
  • Environment - Bioconcentration factors for 2,4-D as 2-ethylhexyl ester (EHE) and butoxyl ester (BEE) in fish.
  • Occupational exposure - As a condition of continued registration, registrants are required to obtain access to data under the Broadleaf Turf Herbicide Task Force or the Outdoor Residential Exposure Task Force or submit equivalent data.

Registrants had committed to the development of new data to address the chemistry and toxicology data requirements, and they were submitted to the PMRA for review. Note that an extended one-generation reproduction toxicity study was conducted in lieu of the two separate toxicology studies. Upon receipt of these data, the PMRA completed a review and determined that they were acceptable and supported the re-evaluation decision for 2,4-D, as described in Re-evaluation Decision RVD2008-11, (2,4-Dichlorophenoxy)acetic Acid.

With respect to the environmental data requirement, registrants submitted a rationale for a data waiver, which was reviewed by the PMRA and deemed acceptable. In addition, registrants provided the necessary information to satisfy the occupational exposure requirement.

As a result of the above, the PMRA can now conclude that the data and information submitted under section 12 of the Pest Control Products Act support the regulatory decision for 2,4-D and no further changes are required.

Additional Information

If there are any questions or for additional information, please contact Publications.

PMRA documents can be found on the Pesticides and Pest Management portion of Health Canada's website at or through the Pest Management Information Service.

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