California regulators are assessing two new pesticide active ingredients that have sparked renewed debate over PFAS, the persistent "forever chemicals" increasingly detected in soils, water systems and agricultural environments. Although the U.S. Environmental Protection Agency has authorized cyclobutrifluram and isocycloseram for national use, the products cannot be applied in California until the state completes its scientific review-an approval process that commonly takes months or even years.

Cyclobutrifluram is approved for use on romaine lettuce, cotton, soybeans, turf and ornamental plants, while isocycloseram is authorized for a broad set of agricultural crops, including brassicas such as cabbage, broccoli and Brussels sprouts. Federal regulators promote the products as additional tools for crop protection, but scientists warn the formulations fall into categories that many global experts define as PFAS, a chemical group known for extreme persistence and harmful biological effects.

California currently uses an estimated 2.5 million pounds of PFAS-containing pesticides each year, according to an Environmental Working Group analysis. The Central Valley accounts for the highest volumes, with Fresno County alone reporting more than 2 million pounds applied between 2018 and 2023. Stakeholders say this trend highlights the urgency of understanding how new fluorinated compounds might accumulate across agricultural landscapes.

While the EPA limits its PFAS definition to chemicals with two or more fluorinated carbon atoms, many researchers and regulatory bodies classify any compound with at least one fully fluorinated carbon as PFAS. This broader definition encompasses both newly approved pesticides. The distinction matters because PFAS molecules can take centuries to degrade and are linked to decreased fertility, immune dysfunction and increased cancer risk.

Environmental health experts also warn that both active ingredients can degrade into trifluoroacetic acid (TFA), an ultra-short PFAS highly soluble in water and exceedingly difficult to remove using conventional treatment systems. Rising TFA concentrations have already been detected in groundwater and marine environments, raising concerns about long-term accumulation and unknown ecological impacts.

Advocacy groups argue that applying fluorinated chemicals directly to food crops poses unacceptable risks. They note that California's experience with legacy pesticides like DDT, banned decades ago after widespread environmental contamination, should serve as a warning against repeated reliance on long-lived synthetic compounds.

Industry groups, including Western Growers, counter that growers urgently need new pest-control tools as resistance spreads and economic pressures intensify. Many producers argue that limiting access to new technologies could compromise yields and undermine the sector's resilience.

California's Department of Pesticide Regulation is conducting a full scientific evaluation of both active ingredients, including their breakdown products, environmental persistence, toxicity and potential exposure pathways. The agency has not provided a timeline for a decision, though experts suggest approvals could occur within a year depending on data requirements and regulatory outcomes.

As scrutiny grows around PFAS in consumer products, water supplies and agricultural systems, California's decision on these pesticides will have national implications. It will test how regulators balance crop protection needs with concerns about chemical persistence, cumulative exposure and long-term environmental stewardship.