A significant increase in enforcement activity under California’s Proposition 65 is placing renewed scrutiny on food products that may contain aflatoxins. In recent months, private enforcers have issued dozens of 60-day notices of violation (NOVs) alleging that food manufacturers, distributors, and retailers failed to provide warnings for alleged aflatoxin exposure. The notices span a broad range of products, including nut butters, dried fruits and snacks, spices, and other commonly consumed foods.
Background on Proposition 65
Proposition 65 requires California to maintain and update a list of chemicals known to cause cancer, birth defects, or other reproductive harm. Businesses that expose individuals to listed chemicals must provide a “clear and reasonable” warning unless an affirmative defense applies. For example, a business has an affirmative defense if it can demonstrate that the anticipated exposure level poses no significant risk of cancer (for carcinogens) or will have no observable effect (for reproductive toxicants).
For listed carcinogens, the relevant safe harbor standard is the No Significant Risk Level (NSRL), defined as the daily intake level calculated to result in one excess case of cancer in an exposed population of 100,000 individuals over a 70-year lifetime.
If California’s Office of Environmental Health Hazard Assessment (OEHHA) has not established a safe harbor level for a chemical, businesses that may expose individuals to that chemical must provide a Proposition 65 warning unless they can independently demonstrate that the exposure poses no significant risk.
Proposition 65 is enforced primarily through private actions. Before filing a lawsuit, a private plaintiff must serve a 60-day notice of violation on the alleged violator, the California Attorney General’s Office, and applicable district attorneys and city attorneys. That 60-day period allows the business to correct the alleged violation, negotiate a settlement, or prepare a defense. If no public enforcement action is initiated within 60 days, the private plaintiff may proceed with litigation seeking injunctive relief, civil penalties of up to $2,500 per day per violation, and recovery of attorneys’ fees.
Aflatoxin Listing and Affected Products
Aflatoxins have been listed under Proposition 65 as chemicals known to the state of California to cause cancer since January 1, 1988. They are naturally occurring mycotoxins produced by certain species of Aspergillus mold and can contaminate agricultural commodities during growth, harvest, and storage in warm and humid conditions.
Critically, OEHHA has not adopted an NSRL for aflatoxins. Under OEHHA’s most recent priority list for NSRL development, aflatoxins remain in the Third Priority category, meaning the agency has not prioritized the development of a numeric safe harbor for this chemical group. As a result, businesses cannot automatically rely on a regulatory safe harbor to avoid the warning requirement. Instead, businesses must independently develop their own risk assessments to demonstrate that an exposure poses “no significant risk” or consider providing a Proposition 65 warning.
Aflatoxins are commonly found in nut butters (including almond butter, peanut butter, and cashew-based products); dried fruits and baked goods and bars containing dried fruits; spices (including paprika, chili powder, chipotle powder, coriander, turmeric, and black pepper); corn-based products (including cornmeal and corn flour); milk and dairy; and grains and oilseeds (including rice, wheat, sorghum, cottonseed, and soybeans).
Recent Surge in NOVs for Aflatoxins
Recently filed 60-day notices with the California Attorney General’s Office show a marked increase in aflatoxin-related Proposition 65 enforcement during 2025 and 2026.
On May 22, 2026, Environmental Health Advocates Inc. filed at least 30 separate NOVs in a single coordinated batch, all alleging aflatoxin exposure in food products sold by major retailers and manufacturers. Several of these notices also allege exposure to ochratoxin A, another listed mycotoxin, suggesting a broader enforcement focus.
The May 2026 filings were preceded by a series of notices filed between August and September 2025 by Center for Consumer Safety LLC. These earlier notices targeted primarily spices, nut butters, and corn-based products.
Several aspects of the recent enforcement surge warrant attention. First, the sheer volume and coordination of the May 2026 filings—at least 30 notices in a single day—suggest a deliberate enforcement strategy that may continue. Second, the targeted products extend beyond traditional categories such as peanut butter to include fig-based snacks, date rolls, superfood bars, and almond products. Third, because no NSRL exists for aflatoxins, defendants cannot rely on a numeric safe harbor level and face a more complex defense posture.
Potential Action Items for Companies
Companies that manufacture, distribute, or sell food products in California that may contain aflatoxins should consider taking the following steps.
Review supply chain controls. Companies should identify products in California distribution channels that may contain aflatoxins, particularly nut-based products, dried fruits, spices and ground peppers, corn-based ingredients, and products containing those ingredients. Products susceptible to Aspergillus contamination should be flagged for further evaluation. Companies should also evaluate supplier qualification processes to ensure that suppliers of raw ingredients maintain adequate controls for aflatoxin contamination, including proper storage conditions.
Consider analytical testing. Although Proposition 65 does not require specific testing, companies may consider engaging accredited laboratories to test finished products and raw ingredients for total aflatoxin levels.
Evaluate warning obligations. In the absence of an NSRL for aflatoxins, companies must either provide a Proposition 65 warning or demonstrate through their own quantitative risk assessment that the exposure poses no significant risk—i.e., that it does not result in more than one excess case of cancer per 100,000 individuals exposed over a 70-year lifetime. Companies may consult with a toxicologist experienced in Proposition 65 risk assessment to determine whether their products’ aflatoxin levels can support an affirmative defense.
Implement compliant warnings. If warnings are warranted, companies should ensure they comply with OEHHA’s safe harbor warning regulations, including approved warning language, required format, and methods of transmission. Safe harbor warnings are deemed “clear and reasonable” by regulation and protect against challenges to the adequacy of the warning content. Companies should be aware that updated short-form warning language requirements take effect on January 1, 2028.
Develop a response strategy for NOVs. Companies that receive an NOV should act quickly. The 60-day window provides an opportunity to negotiate a consent judgment or settlement, but it requires prompt attention. Settlement demands in Proposition 65 cases typically include injunctive relief, civil penalties, and reimbursement of plaintiff attorneys’ fees, so companies should evaluate whether settlement, reformulation, warning implementation, or litigation is the best course.
Looking Ahead
The recent increase in aflatoxin-related Proposition 65 enforcement marks a notable expansion of the scale and scope of private enforcement activity targeting the food industry. The coordinated filing of dozens of NOVs in a single day, the growing range of targeted product categories, and the absence of a regulatory safe harbor level for aflatoxins create a challenging compliance landscape for food companies operating in California.
Companies that have not yet assessed their aflatoxin exposure risk should consider doing so now. Those that proactively evaluate product portfolios, implement appropriate protocols, and prepare a response framework for potential NOVs will be better positioned to reduce legal risk and business disruption.
If you have any questions, or would like additional information, please contact one of the attorneys on our Environment, Land Use & Natural Resources team.
You can subscribe to future advisories and other Alston & Bird publications by completing our publications subscription form.