The California Office of Environmental Health Hazard Assessment (OEHHA) has referred ethoprop to the Carcinogen Identification Committee (CIC) for a recommendation on whether the pesticide should remain on the Proposition 65 cancer list. This is a delisting review, not a delisting. Ethoprop stays on the list, and every existing Proposition 65 obligation remains fully enforceable until OEHHA formally acts. For compliance teams, that distinction is the entire story: a favorable outcome is possible, but nothing changes today.
If your organization sells pesticide products, treated commodities, or agricultural inputs into California, this review affects how you manage warnings, supplier data, and discharge obligations over the next several months. This article explains what OEHHA decided, the confirmed timeline, who is affected, and how to keep your compliance position defensible whether ethoprop stays listed or is eventually removed.
Before you adjust anything: Book a compliance risk assessment to confirm where ethoprop and other Proposition 65 substances appear across your product portfolio and California-bound shipments.
Key Takeaways
📌 OEHHA referred ethoprop to the CIC on September 4, 2026, to recommend whether it should remain on the Proposition 65 cancer list.
⚠️ Ethoprop remains listed. All warning and discharge obligations continue unchanged during the review.
⏳ The 45-day public comment period closes October 19, 2026; the CIC meets November 17, 2026, in Sacramento and online.
📊 The review follows US EPA's reclassification of the evidence to "Suggestive Evidence of Carcinogenic Potential," which affects the original listing basis.
🏭 Agrochemical manufacturers, growers, distributors, retailers, and food and commodity processors handling California exposures are affected.
📄 Compliance teams should maintain current warnings and preserve evidence of where ethoprop appears in products and supply chains until a formal decision is issued.
What OEHHA Actually Decided
On September 4, 2026, OEHHA issued a notice referring ethoprop to the CIC, the state's qualified experts on carcinogenicity under the Safe Drinking Water and Toxic Enforcement Act of 1986. The CIC will recommend whether ethoprop should continue to be included on the Proposition 65 list of chemicals known to cause cancer.
The referral matters because ethoprop was originally listed through the authoritative bodies mechanism — one of four ways a chemical reaches the Proposition 65 list. When the underlying classification from that authoritative body changes, OEHHA can review whether the listing basis still holds. That is precisely what is happening here.
Two points define the current status. First, this is a recommendation process, not a final action. Second, the substance remains listed throughout. Compliance leaders monitoring California Proposition 65 obligations should treat this as a watch item, not an action to relax controls.
Why Ethoprop Is Under Review
Ethoprop (ethoprophos), CAS 13194-48-4, is an organophosphate insecticide and nematicide sold under trade names including Mocap®. It was listed as a carcinogen under Proposition 65 effective in 2001. OEHHA's official listing notice records the listing as effective February 23, 2001, while the published Proposition 65 list records the date listed as February 27, 2001. Both trace to OEHHA.
The listing rested on a US EPA carcinogenicity classification. According to OEHHA's hazard identification document, US EPA later characterized the evidence for ethoprop's carcinogenic potential as "Suggestive Evidence of Carcinogenic Potential." That descriptor sits below the weight-of-evidence threshold that originally supported the Proposition 65 listing through the authoritative bodies mechanism. The CIC will weigh whether the listing should continue given this change.
For manufacturers, the regulatory logic is more useful than the chemistry: a listing can be revisited when the classification that justified it is downgraded. That is why continuous regulatory intelligence and horizon scanning matters. Listings are not permanent, and neither are the obligations attached to them.
Proposition 65 ethoprop delisting review timeline with key 2026 compliance dates
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Confirmed Timeline and Process
The procedural calendar is fixed and verifiable through OEHHA. Compliance teams can plan around these dates.
Date | Event |
|---|---|
December 19, 2025 | Request for relevant information (data call-in) opened |
February 2, 2026 | Data call-in closed (no submissions received) |
September 4, 2026 | OEHHA refers ethoprop to CIC; 45-day comment period opens |
October 19, 2026 | Public comment period closes |
November 17, 2026 | CIC meets in Sacramento and online to recommend on continued listing |
The CIC meeting will be held at the Sierra Hearing Room, 1001 I Street, Sacramento, with online participation available. Organizations with a scientific or commercial interest in the outcome can submit written comments to OEHHA by October 19, 2026, or participate in the meeting. This is the primary window for regulated parties to influence the record before the committee deliberates. Teams tracking chemical and hazmat compliance obligations should calendar these dates now.
Who Is Affected
The review touches every point in the ethoprop value chain that reaches California. Because Proposition 65 applies to exposures within California regardless of where a product is made, the geographic trigger is the point of sale or exposure, not the point of manufacture.
Segment | Who | Why It Matters |
|---|---|---|
Agrochemicals | Pesticide manufacturers and formulators of organophosphate insecticide, nematicide, and fungicide products (e.g., Mocap®) | Product warnings and label review tied to a listed carcinogen |
Agriculture | Growers and licensed applicators (sweet potato, potato, nursery, cabbage, dried beans, corn, hops, mint) | Use practices and downstream commodity exposure |
Distribution & Retail | Distributors, retailers, and marketplaces selling pesticide or treated products into California | Warning-transfer duties and marketplace listing requirements |
Food & Commodities | Processors handling treated raw agricultural commodities | Potential exposure pathways requiring assessment |
Manufacturers with complex bills of materials and multi-supplier sourcing face the hardest task: confirming whether ethoprop is present, at what stage, and whether a California exposure occurs. This is a BOM substance and threshold management problem before it is a legal one. You cannot warn accurately, or defend a decision not to warn, without knowing where the substance sits in your products and supply chain.
What Stays the Same Until OEHHA Acts
This is the most important operational message: nothing changes yet. Referral for review does not alter obligations.
✓ Ethoprop remains on the Proposition 65 list.
✓ Existing warning requirements for exposures continue to apply.
✓ The discharge prohibition (no knowing discharge into drinking water sources) continues to apply.
⚠ Removing warnings now, in anticipation of delisting, creates enforcement exposure.
Proposition 65 enforcement is driven substantially by private plaintiffs, not only the state. Acting on a predicted outcome rather than the current legal status is the classic way compliance teams create liability. A downgrade in EPA's evidence descriptor does not remove a chemical from the list; only a formal OEHHA delisting does. Until then, maintain your controls and your audit-ready documentation.
Proposition 65 ethoprop referral versus delisting comparison for compliance obligations
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The Documentation and Evidence Challenge
A delisting review creates a subtle documentation problem. If ethoprop is eventually delisted, you will want a clean record of when obligations applied and when they ended. If it stays listed, you will want to show continuous compliance. Either way, the value sits in time-stamped, defensible evidence.
Compliance engineers should be able to answer, on demand: Which products contain or may contain ethoprop? Which shipments reach California? What warnings were applied, and from what date? What supplier declarations support the presence or absence of the substance? These are point-in-time questions, and spreadsheets rarely answer them cleanly under audit pressure.
This is where a centralized compliance data backbone changes the outcome. Certivo maintains historic compliance states and time-stamped declarations, so a compliance team can produce point-in-time evidence for internal audits, customer audits, or a private enforcement inquiry without reconstructing history from email. CORA-powered regulatory intelligence links substance data to the specific regulation, so a change in ethoprop's status maps directly to the affected products.
Supply Chain Impact and Supplier Data
The hardest part of any Proposition 65 exposure decision is knowing what suppliers actually put in a product. For ethoprop, that means confirming presence across formulations, treated commodities, and multi-tier inputs. Missing or inconsistent supplier data is the most common reason compliance teams over-warn defensively or, worse, under-warn by accident.
Automated supplier data collection reduces this gap. Instead of chasing declarations by email, compliance and procurement teams can route standardized requests through supplier portals and validate returned documents at intake. When a substance like ethoprop is under review, that infrastructure lets you refresh supplier declarations quickly and confirm exposure status across the portfolio. Teams managing supplier and contractor management at scale need this to respond to regulatory movement without a fire drill.
For manufacturers already handling broader chemical obligations, ethoprop is one substance among many. The same workflow that tracks it should track REACH SVHC, RoHS, and PFAS exposures, because the underlying problem — substance-to-product mapping with defensible evidence — is identical across frameworks.
How AI Supports Proposition 65 Change Management
Proposition 65 is a moving target. OEHHA lists, delists, and revises no-significant-risk levels on an ongoing basis, and enforcement is continuous. Managing this manually means a compliance team is always reacting after the fact.
AI-native compliance automation shifts the posture from reactive to continuous. CORA-driven compliance intelligence monitors regulatory sources, flags status changes such as the ethoprop referral, and maps each change to the products and suppliers it touches. AI document parsing extracts substance data from supplier certificates and safety data sheets, validating what is actually present rather than what a spreadsheet claims.
The objective is not to eliminate compliance risk, which no software can do. It is to reduce surprises, shorten evidence-retrieval time, and give leadership visibility into exposure across jurisdictions. For a substance under active review, that means you learn about the CIC's recommendation and its portfolio impact immediately, and you can act on the current legal status with confidence. Explore how Certivo approaches proactive compliance risk across frameworks.
What Compliance Teams Should Do Now
The ethoprop delisting review calls for disciplined monitoring, not premature action. A defensible position holds regardless of the CIC's recommendation.
Maintain current controls. Keep all ethoprop-related warnings and discharge controls in place. Do not relax anything before a formal OEHHA delisting.
Confirm exposure. Map where ethoprop appears across products, formulations, and treated commodities that reach California, using verified supplier data.
Preserve evidence. Retain time-stamped records of warnings, supplier declarations, and decisions so you can demonstrate compliance for any period under review.
Engage if warranted. If your organization has relevant scientific data or a commercial stake, submit written comments to OEHHA before October 19, 2026, or participate in the November 17 meeting.
Prepare for either outcome. Build a plan to update warnings and documentation quickly if delisting occurs, and to continue current obligations if it does not.
Struggling to confirm where a listed substance sits across your portfolio? Request a compliance review to see how Certivo maps substances to products and preserves audit-ready evidence across Proposition 65 and other frameworks.
Conclusion
The ethoprop delisting review is a reminder that Proposition 65 status is dynamic, but obligations are not optional while a chemical remains listed. OEHHA has referred ethoprop to the CIC because US EPA downgraded the underlying carcinogenicity evidence, and the committee will recommend on continued listing at its November 17, 2026 meeting. Until OEHHA formally acts, ethoprop stays on the list and every warning and discharge obligation continues.
The organizations that handle this well will not be the ones that guess the outcome. They will be the ones that maintain current controls, know exactly where the substance sits in their products and supply chains, and hold time-stamped evidence to prove it. That is the difference between reacting to a regulatory change and being ready for it.
To move from reactive tracking to continuous readiness across Proposition 65 and every framework that affects your products, speak with a compliance specialist.
Lavanya
Lavanya is an accomplished Product Compliance Engineer with over four years of expertise in global environmental and regulatory frameworks, including REACH, RoHS, Proposition 65, POPs, TSCA, PFAS, CMRT, FMD, and IMDS. A graduate in Chemical Engineering from the KLE Institute, she combines strong technical knowledge with practical compliance management skills across diverse and complex product portfolios.
She has extensive experience in product compliance engineering, ensuring that materials, components, and finished goods consistently meet evolving international regulatory requirements. Her expertise spans BOM analysis, material risk assessments, supplier declaration management, and test report validation to guarantee conformity. Lavanya also plays a key role in design-for-compliance initiatives, guiding engineering teams on regulatory considerations early in the product lifecycle to reduce risks and streamline market access.
Her contributions further extend to compliance documentation, certification readiness, and preparation of customer deliverables, ensuring transparency and accuracy for global stakeholders. She is adept at leveraging compliance tools and databases to efficiently track regulatory changes and implement proactive risk mitigation strategies.