This [issue and concern] is nothing new. These forever chemicals were invented in 1938 and have been widely used ever since. Isocycloseram is not a pfas by legacy classification, but is kinda a "forever chemical" in broad definitions, and all orthomolecular chemistries are very different form each other. The toxicity profiles of C8 carbon backbones are significantly greater than other pfas/pfos molecules. They are are so highly toxic that in parts per trillion, the size of a grain of rice in an olympic swimming pool, causes health issues. . Irrespective, I remain highly opposed to these novel molecules, as I have been since delving in their mechanisms of action in 1972. "In California alone, ~2.5 million pounds of PFAS-containing pesticides (including the above and others like oxyfluorfen, bifenthrin, and penthiopyrad) are applied annually to cropland, totaling ~15 million pounds from 2018–2023," and that does not include the pfas modifiers that are added to non-pfas chemicals in field mixes:
C8 (PFOA and PFOS) is a PFAS with an eight-carbon backbone that was not intentionally used in agriculture, but it contaminates agricultural environments through by-products of industrial manufacturing, land application of contaminated sludge, and the use of contaminated irrigation water. This contamination allows C8 to enter crops, potentially affecting food safety and health.
Contamination pathways in agriculture
- Contaminated irrigation water: C8 is a persistent chemical that can be found in surface and groundwater, which are used for irrigating crops.
- Contaminated biosolids/sludge: Municipal sludge containing PFAS from manufacturing and other sources is sometimes used as fertilizer in agriculture, introducing C8 into the soil.
- Industrial by-products: Manufacturing processes that used C8 created significant environmental contamination of soil and water, which then affected nearby agricultural lands.
Impact on crops and food
- Uptake by plants: Plants can absorb C8 from contaminated soil and water through their roots.
- Bioaccumulation: The concentration of PFAS in plants is variable depending on the crop, with some studies showing higher accumulation in shoot vegetables than in root vegetables or grains.
- Food chain entry: Plants absorb these chemicals, which can then enter the food chain, posing a risk to human and animal consumers.
Health concerns associated with C8 exposure
Exposure to C8 has been linked to several adverse health effects in both animal and human studies, including:
- Kidney and testicular cancer
- Thyroid disease
- High cholesterol
- Ulcerative colitis
- Pregnancy-induced hypertension
EPA Policy on PFAS in Pesticide Formulations and Field Applications
Yes, different PFAS (per- and polyfluoroalkyl substances) molecules are allowed to be used in field applications of fungicides, herbicides, and pesticides under current U.S. Environmental Protection Agency (EPA) regulations, provided they undergo individual risk assessments and meet safety standards. However, this allowance is highly nuanced due to varying definitions of PFAS, ongoing regulatory scrutiny, and distinctions between active and inert ingredients. Below, I'll break this down based on the latest available information as of November 2025.
Key Context on PFAS Definitions and EPA Approach
EPA's Narrow Definition
In 2023, the EPA adopted a specific structural definition of PFAS for regulatory purposes under the Toxic Substances Control Act (TSCA) and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). This definition generally requires at least one fully fluorinated methyl (-CF₃) or methylene (-CF₂-) carbon atom without attached hydrogen, chlorine, bromine, or iodine. Under this lens, **no currently registered pesticidal active ingredients qualify as PFAS**, and the EPA has finalized the removal of 12 specific PFAS compounds previously approved as inert (non-active) ingredients in December 2022 (effective through 2025 with no reversals). These inerts were not in active use and posed unnecessary risks.
Broader Scientific and International Definitions
Many organizations (e.g., OECD, EU, and independent researchers) use a wider definition encompassing any substance with one or more fluorinated carbons. Under this broader view, **numerous EPA-approved active ingredients in pesticides are classified as PFAS**, and the agency has approved several new ones in 2025 for field use. The EPA evaluates each chemical individually under FIFRA, regardless of PFAS classification, focusing on chemical-specific risks like toxicity, environmental persistence, and exposure pathways. Critics argue this approach underestimates cumulative PFAS risks, but the EPA maintains it ensures "robust, chemical-specific" safety.
Field Applications
"Field applications" refer to real-world uses like spraying on crops (e.g., corn, soybeans, almonds), turf, or orchards. Approved PFAS-containing pesticides are explicitly labeled for such uses, with tolerances set for residues in food and environmental monitoring required. No blanket ban exists for PFAS in these contexts; approvals continue if data supports safety.
Examples of Approved PFAS Molecules for Field Use
Since 2023, the EPA has registered or proposed at least five active ingredients that fit the broader PFAS definition for field applications in fungicides, herbicides, and insecticides. These are evaluated for benefits (e.g., pest control efficacy) versus risks (e.g., persistence, breakdown to other PFAS like trifluoroacetic acid [TFA]). Here's a summary:
| Herbicide | Epyrifenacil | Weed control in corn, soybean, wheat, and canola fields | Proposed for registration (announced Nov 5, 2025) | Breaks down to TFA (a persistent PFAS byproduct); evaluated for groundwater risks. |
| Insecticide | Isocycloseram | Pest control on food crops (e.g., oranges, tomatoes, almonds, peas, oats), lawns, and golf courses | Approved (Nov 20, 2025) | Second PFAS approval in two weeks under current administration; persistent in soil. |
| Fungicide | Cyclobutrifluram | Disease control on turf, ornamental plants, romaine lettuce, cotton, and soybean seeds | Approved (Nov 5, 2025) | Targets soil-borne pathogens; approved despite environmental persistence concerns. |
| Fungicide | Fluoxapiprolin | Fungal control in agricultural fields (e.g., potatoes, grapes) | Proposed/Under review (Sep 2025) | New piperidinyl-thiazole-isoxazoline class; no major risks identified in EPA memo. |
| Fungicide | Fluopyram | Soil and foliar fungal diseases in crops (e.g., strawberries, nuts) | Registered and in use (ongoing since 2013) | ~519,000 lbs applied in California (2018–2023); Denmark banned in 2025 over groundwater contamination. |
Usage Scale
In California alone (a major agricultural state), ~2.5 million pounds of PFAS-containing pesticides (including the above and others like oxyfluorfen, bifenthrin, and penthiopyrad) are applied annually to cropland, totaling ~15 million pounds from 2018–2023. These are used across 58 counties, primarily in high-production areas like Fresno and Kern.
Inert Ingredients
No PFAS inerts are approved, but some formulations may include fluorinated surfactants for dispersion/absorption. Any unintentional PFAS (e.g., from fluorinated HDPE packaging) is regulated under TSCA, not FIFRA, and EPA testing in 2025 found no detectable levels in products.
Regulatory Trends and Concerns
State and International Variations
While federally approved, states like California have not restricted these yet, though Denmark and the EU have banned several (e.g., fluopyram, flufenacet) due to PFAS leaching into water. U.S. litigation challenges EPA approvals under FIFRA and the Endangered Species Act.
EPA's Stance
The agency emphasizes that fluorinated pesticides offer "unique benefits" and are registered only after extensive data review. They created a dedicated webpage in November 2025 to explain this process. For unintentional contamination, EPA's 2025 testing confirmed no PFAS in 10 sampled products, attributing past detections to packaging leaching.
In summary, while the EPA's strict definition prohibits certain PFAS, different molecules meeting broader PFAS criteria are indeed EPA-approved for field applications in fungicides, herbicides, and pesticides.
So, this is nothing new, just more of the same old thing. Stop the Pollution!
International Hyperbaric Medical Foundation
Dr Merrel Holley, DSc, President
&
The TOR Institute of Antiaging, Tissue & Organ Regeneration
Dr Merrel Holley, DSc, Senior Research Scientist
https://www.ihmf.org
Greater New Orleans, LA
985-397-4692