California AB 1603: What Pesticide Registrants Need to Know About New PFAS Disclosure Requirements

What the Law Now Requires 

California Assembly Bill 1603 amends the Food and Agricultural Code by directing DPR to take several concrete steps no later than January 1, 2028 to identify and disclose PFAS pesticide ingredients in California-registered pesticides.  DPR must now flag whether each registered pesticide contains PFAS pesticide ingredients in its online pesticide use reporting database, designate PFAS as a searchable category of interest within that database, and incorporate PFAS pesticide use trends into its annual pesticide use report and related reporting documents on an ongoing basis. Separately, DPR must compile and publish on its website a complete list of all registered pesticides containing PFAS pesticide ingredients and deliver that list to every county agricultural commissioner in California. After the initial publication, DPR is required to update the list and redistribute it to all county commissioners within 60 calendar days whenever a new PFAS-containing pesticide is registered.  

What this means for registrants of pesticides for sale in California is that: 

(1) any registered pesticide DPR has determined contains a PFAS pesticide ingredient will now be searchable and filterable by that characteristic by the public, including researchers, journalists, litigants, or regulators who access DPR's online database;  

(2) PFAS-containing pesticide registrations, including the volume of their use in California, will be highlighted and analyzed in DPR's published annual reports, increasing the visibility of those products; and  

(3) The submission to county commissioners could be significant, given they are the primary local enforcement authorities for pesticide regulation in California. Submitting a list of PFAS-containing registrations to California's 58 county agricultural commissioners allows for heightened local scrutiny, targeted use monitoring, and potential county-level enforcement. The PFAS pesticide database could also increase the risk of challenges to pesticide registrations (both in California and federally), third-party enforcement of consumer protection laws, or tort lawsuits.   

Why This Law Was Passed 

The Legislature set out its purpose in enacting AB 1603 by first noting that PFAS are increasingly being added to pesticides. According to one report, the U.S. Environmental Protection Agency (EPA) has approved 70 active ingredient PFAS pesticides, based on the broad one-fully-fluorinated-carbon definition utilized by AB 1603 (though, notably, EPA defines PFAS more narrowly). DPR registered 53 of these alleged PFAS pesticides.  

The Legislature enacted AB 1603 with the stated intent of addressing the use of PFAS pesticides as a class; reducing the presence of all PFAS pesticides on California-grown produce and in California's soil, air, and water; and beginning to phase out the use of PFAS pesticides. Thus, the disclosure infrastructure created by AB 1603 is not simply to inform the public, but to lay the groundwork for future restrictions. 

What is a “PFAS Pesticide Ingredient?” 

Whether a registrant's product will be publicly identified as a PFAS-containing pesticide depends on whether it contains "PFAS pesticide ingredients" as defined by the statute. AB 1603 codifies two interlocking definitions: 

• "PFAS" is defined as "a class of fluorinated organic chemicals containing at least one fully fluorinated carbon atom." 

• "PFAS pesticide ingredients" means "PFAS that are intentionally added to a pesticide as active, adjuvant, or inert ingredients." 

This definition of PFAS is broad and mirrors that used in many other state PFAS laws, covering the full range of per- and polyfluoroalkyl substances that share the characteristic of at least one fully fluorinated carbon atom. Similarly broad, is the concept of "PFAS pesticide ingredients," which includes all PFAS that are intentionally added — whether as active, adjuvant, or inert ingredients and with no concentration limit. This scope carries practical significance for registrants: 

• Active ingredients that are PFAS compounds (such as fluoro-based fungicides or herbicides) will clearly be captured. 

• Adjuvant and inert ingredients that qualify as PFAS — such as certain fluorinated surfactants commonly used as spreader-stickers or wetting agents — will also trigger public disclosure if they are intentionally added to the formulation as distributed. If, however, a pesticide label merely permits or encourages use of an adjuvant together with the pesticide, such as a tank-mix recommendation, the pesticide would not be captured on the PFAS pesticide list as a result. 

• Incidental PFAS — for example, trace PFAS from manufacturing processes, equipment, or water sources, rather than from deliberate formulation choices — would fall outside the definition, given the statute's "intentionally added" limitation. Registrants should nonetheless be cautious about relying on this distinction without a thorough formulation review, as DPR may interpret "intentionally added" broadly. 

Do Registrants Have Affirmative Disclosure Obligations? 

No.  As the law is currently written, registrants do not have any new affirmative disclosure obligations. AB 1603 imposes all obligations on DPR, not on registrants. Specifically: 

• The law imposes no requirement that registrants notify DPR that a product contains PFAS pesticide ingredients. The process DPR will undertake to determine whether pesticides contain PFAS pesticide ingredients is yet to be seen, however, and is an issue worth watching. 

• There is currently no requirement in the law that registrants submit any new reports or certifications concerning PFAS content. 

• There is no requirement that PFAS disclosures appear on the pesticide label. AB 1603 does not amend California's pesticide labeling requirements, and the bill contains no provision directing manufacturers or registrants to add any PFAS-related statement to a product label. 

When Will Public Disclosure of Registrants' Products Occur? 

• On or before January 1, 2028 (earlier if DPR posts 2026 database data before that date): DPR must flag PFAS-containing pesticides in the public database and publish the list of all registered PFAS-containing pesticides, simultaneously submitting that list to all 58 county agricultural commissioners. 

• After that publication, within 60 calendar days of a new PFAS-containing registration: DPR must update its public list and notify all county commissioners. For registrants bringing new PFAS-containing products to the California market after the initial list is published, public identification and county notification will follow rapidly after registration is granted. 

Key Takeaways for Registrants 

AB 1603 does not ban or restrict any PFAS-containing pesticide, and it imposes no new labeling or self-disclosure requirements on registrants. The Legislature has expressly stated, however, its intent to address the use of PFAS pesticides as a class and to begin phasing out their use — making clear that AB 1603 is the opening move in a more expansive regulatory program.  

Registrants should consider the following actions: 

• Conduct a full formulation audit. Before January 1, 2028, identify every registered California pesticide that contains PFAS pesticide ingredients — including active, adjuvant, and inert ingredients meeting the "at least one fully fluorinated carbon atom" threshold. 

• Do not rely on the absence of a labeling mandate as a signal of low risk. The Legislature's intent to reduce and one day phase out PFAS pesticides, combined with the public database and annual trend reporting, creates reputational, regulatory, and tort risk for registrants of PFAS-containing pesticides well before any formal restriction is enacted. 

• Assess the likelihood of challenges to registrations of pesticides containing PFAS. The ready access to a list of pesticides containing PFAS is likely to make such pesticides more visible to those interested in challenging pesticide registrations. Consider whether any of your PFAS-containing pesticide registrations warrant particular attention in this context. 

• Engage in the regulatory process proactively. DPR is likely to use the data and trends it compiles under AB 1603 to inform future rulemaking. Registrants of PFAS-containing pesticides have a strong interest in participating in any DPR comment periods or stakeholder processes that follow.