The Canadian Pest Management Regulatory Agency (PMRA) is proposing to grant continued registration for ethephon based on the evaluation of currently available scientific information, while risk mitigation measures are required to be in place to further protect human health and the environment.
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.
As a result of the re-evaluation of ethephon, further risk mitigation measures as summarized below for product labels are being proposed.
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.
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) before 26 April 2018.