Proposed Re-evaluation Decision PRVD2018-01, Ethephon and Its Associated End-use Products

This consultation is now closed

Pest Management Regulatory Agency
26 January 2018
ISSN: 1925-0967 (PDF version)
Catalogue number: H113-27/2018-1E-PDF (PDF version)

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Table of Contents

Proposed Re-evaluation Decision

Under the Pest Control Products Act, all registered pesticides must be regularly re-evaluated by Health Canada’s Pest Management Regulatory Agency (PMRA) to ensure that they continue to meet current health and environmental safety standards and continue to have value. The re-evaluation considers data and information from pesticide manufacturers, published scientific reports, and other regulatory agencies. The PMRA applies internationally accepted risk assessment methods as well as current risk management approaches and policies.

Ethephon is a plant growth regulator intended to promote fruit ripening, abscission, flower induction, and an increase in lateral branching through the release of ethylene gas, a natural plant hormone. Ethephon is applied as a broadcast foliar spray via ground, aerial, or backpack sprayer equipment and is used in a variety of crops including cereals, apples, sweet and sour cherries, blueberries, field tomatoes and tobacco, as well as in potted greenhouse ornamentals. It is registered for commercial use only.

This proposed re-evaluation decision (PRVD2018-01) presents the proposed regulatory decision for the re-evaluation of ethephon including proposed risk mitigation measures to further protect human health and the environment, as well as the science evaluation on which the proposed decision was based. All products containing ethephon registered in Canada are subject to this proposed re-evaluation decision. Proposed Re-evaluation Decision PRVD2018-01, Ethephon and Its Associated End-use Products is subject to a 90-day public consultation period, during which the public, including manufacturers and stakeholders, may submit written comments and additional information to the PMRA Publications Section. The final re-evaluation decision will be published taking into consideration the comments and information received.

Outcome of Science Evaluation

Ethephon is especially of value for field tomatoes intended for processing, as it promotes uniform ripening thus facilitating the mechanical harvest. It is also of value for greenhouse ornamentals, as it promotes lateral branching, which is desirable for the retail market.

With respect to human health, dietary risks of concern were identified resulting in proposed mitigation measures including cancellation of uses on apple trees when fruit are present. Canadian maximum residue limits (MRLs) for ethephon are currently specified for various commodities. With the proposed measures to minimize risk, Canadian MRLs for ethephon on apples, apple juice, citrus fruits, grapes, and raisins are being proposed to be revoked.

Risks of concern were also identified for certain occupational exposures to ethephon, resulting in the addition of engineering controls, additional personal protective equipment (PPE), limiting the amount of product handled in a day, and lengthening the restricted-entry interval (REI) as additional risk reduction measure.

In the environment, ethephon at high enough concentrations can pose risks to birds, mammals and terrestrial plants. It is however not expected to affect the environment when used according to the proposed label directions, which include advisory statements and spray buffer zones.

Proposed Regulatory Decision for Ethephon

Under the authority of the Pest Control Products Act and based on the evaluation of currently available scientific information, products containing ethephon are being proposed for continued registration in Canada, while risk mitigation measures are required to be in place to further protect human health and the environment.

Registered pesticide product labels include specific directions for use. Directions include risk mitigation measures to protect human health and the environment that must be followed by law. As a result of the re-evaluation of ethephon, further risk mitigation measures as summarized below for product labels are being proposed.

Human Health

To protect consumers, workers handling ethephon, and those entering treated areas, the following risk mitigation measures are proposed:

  • Cancellation of uses on apple trees when fruit are present.
  • Revocation of the existing MRLs for apple, apple juice, citrus fruit, grape, and raisin such that they will be subject to the general maximum residue limit (GMRL).
  • Requirement for additional PPE and engineering controls when mixing/loading and applying to various crops.
  • Restrictions on amount handled per day.
  • Requirement for lengthened REIs for some postapplication activities.
  • Requirement for a statement to promote best management practices to minimize human exposure from spray drift or spray residues resulting from drift.


  • Environmental hazard statements for birds, mammals and non-target plants.
  • To reduce the potential for runoff of ethephon to adjacent aquatic habitats, precautionary statements for sites with characteristics that may be conducive to runoff and when heavy rain is forecasted are required. In addition, a vegetative strip between the treatment area and the edge of a water body is recommended to reduce runoff of ethephon to aquatic areas
  • Terrestrial spray buffer zones for the protection of non-target plants.

International Context

Canada is part of the Organisation for Economic Co-operation and Development (OECD), which provides a forum in which governments from member countries can work together to share experiences and seek solutions to common problems.
Ethephon is currently acceptable for use in other OECD member countries, including the European Union, the United States, and Australia. As of 29 September 2017, no decision by an OECD member country to prohibit all uses of ethephon for health or environmental reasons has been identified.

Next Steps

The public, including manufacturers and stakeholders, are encouraged to submit additional information that could be used to refine risk assessments (exposure data or use information) during the 90-day public consultation periodFootnote 1.

All comments received during the 90-day public consultation period will be taken into consideration in preparation of re-evaluation decision document,Footnote 2 which could result in revised risk mitigation measures. The re-evaluation decision document will include final re-evaluation decision, the reasons for it and a summary of comments received on the proposed re-evaluation decision with the PMRA’s responses.


Footnote 1

“Consultation statement” as required by subsection 28(2) of the Pest Control Products Act.

Return to footnote 1 referrer

Footnote 2

“Decision statement” as required by subsection 28(5) of the Pest Control Products Act.

Return to footnote 2 referrer

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