EPA Review of Thiram, Ferbam, and Ziram
By: Melanie L. Lewis Ivey, Associate Professor, Extension Fruit Pathologist, Department of Plant Pathology
This article can be found in the January 2024 issue of Ohio Fruit News.
In December 2023, the Environmental Protection Agency (EPA) proposed an interim decision for the registrations for thiram, ferbam and ziram. Despite updates and recommendations for ziram, presented during the public comment period for the 2021 proposed interim decision, changes were not made to the previous risk picture and proposal.
Thiram, ferbam and ziram are critical to the successful management of fruit diseases and the prevention of fungicide resistance development. Final decisions on the proposed interim decisions are scheduled for April-June 2024. An open 60-day public comment period is planned for the beginning of 2024. Once the comment period opens, comments can be submitted on-line or by mail. Open comment periods are announced at www.epa.gov/pesticide-reevaluation.
Representatives from the EPA have emphasized that without new data or significant numbers of comments, the proposed interim decision on these products is unlikely to change.
The EPA will only announce final changes to the registrations of all pesticides through the “Bulletins Live – 2” website. However, the OSU Extension Specialty Crop Team will make every effort to keep fruit producers in the state updated.
Figure 1. Peach leaf curl is most effectively controlled using Ferbam or Ziram. Image courtesy of K. Peter, Penn State University.
Thiram
Docket EPA-HQ-OPP-2015-0433
Risks of Concern: There are risks of concern for “fish (both freshwater and estuarine/marine), aquatic invertebrates, mammals, terrestrial invertebrates, birds, and aquatic and terrestrial plants.” In addition, there are “exposure concerns to occupational handlers and post application risks”.
Proposed Mitigation: To address the risks of concerns for thiram the following mitigation strategies were proposed.
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Cancellation of all non-seed treatment uses such as strawberries, peaches, non-bearing trees, shrubs, nursery stock, ornamentals.
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Cancellation for all commercial seed treatment uses.
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Only on-farm seed treatment for liquid formulations and use of a PF10 respirator for some crops (snap bean, rice, soybean, and wheat).
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Limit animal repellency use in nursery settings (ornamentals, vegetables, trees, container stock) to 84178-1 only. This product is also registered for other use sites and those uses must be removed from the label. Applications must be made with a manually pressurized handgun. All other products must remove their animal repellency use from the label.
Ferbam
EPA-HQ-OPP-2015-0567
Risks of Concern: There are risks of concern for “fish (both freshwater and estuarine/marine), aquatic invertebrates, mammals, terrestrial invertebrates, and birds.” In addition, there are “exposure concerns to occupational handlers and occupational post application risks for workers”.
Proposed Mitigation: To address the risks of concerns for ferbam the following mitigation strategies were proposed.
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Cancellation of all uses on apple, pear, citrus, mango, and cranberries.
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Restrict the application method to only be applied by a mechanically pressurized handgun on peach and nectarine for dry flowable formulations and require the use of a PF50 respirator.
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Only dormant period applications for peaches and nectarines.
Ziram
EPA-HQ-OPP_2015-0568
Risks of Concern: There are risks of concern for “fish (both freshwater and estuarine/marine), aquatic invertebrates, mammals, birds, and terrestrial invertebrates”. In addition, there are “dermal and inhalation exposures to occupational handlers, post-application occupational risks (dermal), and bystander (non-occupational) risks to adults (dermal) and children (combined dermal and incidental oral)”.
Proposed Mitigation: To address the risks of concerns for ziram the following mitigation strategies were proposed.
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Cancellation of all uses on all crops.
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Cancellation of uses for paint preservatives.
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Engineering controls for the non-paint materials preservative uses.
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Reducing the maximum application rate in all ziram-preserved building materials.
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Limiting application to the dry-end of the paper preservation process.