The U.S. Environmental Protection Agency (EPA) has set a tolerance level for residues of the fungicide mefenoxam on palm oil, effective as of November 4, 2024. This decision, made in response to a petition by Syngenta Crop Protection, establishes a maximum residue limit of 0.02 parts per million (ppm). Stakeholders may submit objections or hearing requests until January 3, 2025, in compliance with the Federal Food, Drug, and Cosmetic Act (FFDCA).
Background on Mefenoxam and Its Use
Mefenoxam, a systemic fungicide, is used to prevent fungal growth by inhibiting protein synthesis in fungi. It is commonly applied in agricultural settings due to its effectiveness and is an enriched formulation of metalaxyl, which has similar toxicity. This new tolerance for palm oil aligns with EPA’s ongoing regulatory efforts to ensure that pesticide residues in food products meet rigorous safety standards.
Toxicological and Safety Assessments
EPA’s decision follows a comprehensive risk assessment that determined the acceptable levels of mefenoxam in food products, including dietary exposure analysis for the general U.S. population and specific vulnerable groups such as infants and children. As per the EPA’s findings, the established limit is deemed safe, with aggregate exposure from mefenoxam residues falling well below the agency’s level of concern. Notably, the assessment indicated no significant cancer risk associated with mefenoxam exposure in humans.
Key Findings
- Acute Risk Assessment: The acute dietary exposure from food and water represents 27% of the acute population-adjusted dose (aPAD) for the general U.S. population and 55% for infants, the most exposed subgroup.
- Chronic and Intermediate Risks: No chronic dietary endpoint was selected, given the absence of increased hazard from repeated exposure.
- Safety for Infants and Children: An additional margin of safety for infants and children was deemed unnecessary due to reliable data affirming mefenoxam's low risk at these residue levels.
International Residue Standards
While the EPA strives to align its regulations with international standards, no Codex Alimentarius or Canadian maximum residue limits (MRLs) exist for mefenoxam on palm oil. Therefore, the 0.02 ppm tolerance will serve as the primary regulatory benchmark for U.S.-based palm oil producers and importers.
EPA’s Response to Public Comments
The EPA received three public comments regarding the proposed regulation. One comment supported the government’s regulatory process, while two unrelated comments criticised the use of unrelated chemicals. No objections specific to mefenoxam were received, and the EPA proceeded with the rule finalisation.
