U.S. Environmental Protection Agency (EPA) announced the filing and subsequent evaluation of pesticide tolerance petitions submitted by ISK Biosciences Corporation, Concord, Ohio, pursuant to Section 408(d)(3) of the Federal Food, Drug, and Cosmetic Act (FFDCA).
The petitions concerned the fungicide pyriofenone and requested the establishment and modification of residue tolerances under 40 CFR §180.660 for use on certain fruit crops.
Petitions and Requested Tolerances
Petition PP 4F9115 requested the establishment of new tolerances for residues of pyriofenone, including its metabolites and degradates, in or on:
Apple: 0.30 ppm
Apple, wet pomace: 0.69 ppm (as requested)
Cherry subgroup 12-12A: 1.50 ppm
Petition PP 4F9119 requested modification of the existing tolerance for:
Berry, low-growing, subgroup 13-07G (except cranberry): 2.0 ppm
ISK Biosciences Corporation is the registrant of all currently registered pyriofenone pesticide products in the United States.
Public Consultation and Comments
EPA received eight public comments in response to the notice of filing.
Supportive submissions were received from the Northwest Horticultural Council and a student from Utah State University, highlighting:
The impact of fungal diseases on apple and cherry production
The need for additional fungicide tools for disease management
The role of pyriofenone in resistance management through differing Fungicide Resistance Action Committee (FRAC) modes of action
Other public comments raised concerns regarding:
The overall use of pesticides on crops
Environmental persistence
Long-term health impacts, particularly on vulnerable populations
Potential effects on non-target species
Several commenters requested further environmental and health risk assessments prior to tolerance establishment.
EPA Risk Assessment and Safety Determination
EPA reviewed the validity, completeness, and reliability of the available scientific data in accordance with FFDCA Section 408(b)(2). The Agency relied on previously published pyriofenone assessments and incorporated updated dietary exposure evaluations reflecting the new uses.
Key findings include:
Pyriofenone is not likely to be carcinogenic to humans
No acute dietary endpoint was identified
Chronic exposure from food and drinking water is below levels of concern
The highest estimated chronic exposure (children 12 years old) utilized 9.2% of the chronic population-adjusted dose (cPAD)
EPA reaffirmed that there is a reasonable certainty that no harm will result from aggregate exposure to pyriofenone residues, including for infants and children. The Food Quality Protection Act (FQPA) safety factor remains reduced from 10X to 1X, consistent with prior rulemakings.
Final Tolerance Decisions
Based on the data review, EPA established certain tolerances at levels different from those initially proposed, including:
Apple: 0.3 ppm
Apple, wet pomace: 0.5 ppm (lower than requested, based on field trial data and processing factors)
Berry, low-growing, subgroup 13-07G (except cranberry): 2.0 ppm
EPA also made non-substantive revisions to ensure consistency with OECD rounding practices and regulatory naming conventions.
International Considerations
EPA considered international maximum residue limits established by the Codex Alimentarius Commission. While Codex has not set MRLs for pyriofenone on apples or cherries, it has established MRLs for certain berry subgroups at levels different from those adopted in the United States. EPA determined that deviation from Codex levels was justified, including alignment considerations related to Japanese export requirements.
Effective Date and Compliance
The tolerance actions are effective upon publication of the final rule. Where tolerances are lowered or revised, EPA will allow a six-month transition period to support compliance by domestic and international producers, including exporters subject to WTO sanitary and phytosanitary obligations.
Regulatory Significance
This action expands approved uses of pyriofenone on key fruit crops while reaffirming EPAs risk-based regulatory approach under the FFDCA. The decision balances agricultural disease-management needs with consumer health protection and international trade considerations.