Prop. 65 Clearinghouse Conference
On September 8, 2025, industry leaders, regulatory experts, manufacturers, and attorneys gathered in San Francisco for the Prop. 65 Clearinghouse Conference. This annual gathering is the go-to event for anyone needing to stay current with California’s Proposition 65 (“Safe Drinking Water and Toxic Enforcement Act of 1986”). In this post, we highlight the key takeaways—changes, challenges, and actionable insights—for businesses navigating Prop. 65 compliance in 2025 and beyond.
What’s New in Prop. 65 in 2025
Before diving into lessons from the Conference itself, it’s helpful to recall recent regulatory changes that were front of mind at the event:
As of January 1, 2025, new amendments to Proposition 65 took effect. These include revised requirements for short-form warnings (e.g. must include the chemical name, have certain signal words, and meet formatting criteria) and new guidance for warnings in internet catalogs and motor vehicle / marine vessel parts. Stinson
A grace period is in effect—products manufactured before January 1, 2028 may use older wording / formats (depending) even if they are sold later.
Key Themes & Highlights from the conference
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Mark Hepp (Keller & Heckman) presented on what companies need to know to comply—covering warning requirements, enforcement risks, listing chemicals, etc.
This is a useful reminder that foundational compliance missteps (e.g. wrong warning wording, missing chemical name, non-compliance in online warnings) are still a major source of liability.
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Morgan Lewis moderated a panel titled “RSLs and Industry Standards for Listed Chemicals: How Are They Developed and What Do They Have to Do with Prop 65.”
With supply chains stretching globally, many companies rely on RSLs (for apparel, plastics, packaging, etc.). Understanding how those lists intersect with Prop 65 “listing” (officially recognized chemicals) helps businesses anticipate risk.
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One of the breakout sessions focused on “Litigating the Exposure Exemption Defense: Practical Tips and Experience from the Trenches.” Speakers shared case studies, common pitfalls, and what evidence courts tend to accept.
Knowing what kind of data, documentation, or exposure modelling works in court can help companies structure their compliance program defensively.
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Another breakout was “Analytical Chemistry 201”: sampling, sample preparation, QA/QC processes. The importance of reliable labs, standardized methods, and clear measurement was emphasized.
Since many Prop 65 violations or warnings turn on whether levels exceed safe harbor or other thresholds, having high‐quality, defensible testing is critical.
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The Conference also brought up recent settlements under Prop. 65 and emphasized increased scrutiny, especially for consumer products with chemical exposures.
Demonstrates that enforcement isn’t slowing; staying ahead of updates and ensuring warnings are accurate (including on websites, labels, etc.) is not optional.
Implications & Action Items
Based on what was discussed, here are some steps companies in regulated sectors should take now to reduce risk:
Audit existing warning labels — Make sure any short-form warnings include chemical names and meet signal word, symbol, formatting, placement, and visibility criteria per 2025 rules.
Check your product manufacture dates — Because the grace period runs until 2028, for products already in production or stock, plan ahead for relabeling or warning updates when needed.
Review your online presence — Product display pages, hyperlinks, etc., need to meet Prop. 65 online warning requirements. Don’t leave compliance gaps in web sales.
Test and QC — Use reliable labs, ensure sample prep and QA/QC adhere to best practices so your exposure evaluations are defensible.
Monitor settlements & enforcement trends — Settlement terms often reveal what plaintiffs or regulators consider acceptable evidence, wording, or warning practices. Use those as informal benchmarks.
Train internal teams and supply chain partners — Both legal/regulator-facing staff and operations (manufacturing, lab, packaging, web) need awareness of the updated requirements. Suppliers should be asked to certify compliance where relevant.
Why this conference matters
Even though Prop. 65 has been around for decades, amendments and enforcement evolve, and this conference makes a big difference because it:
Provides real-time regulatory updates, directly from experts and firms deeply involved in the law.
Offers peer examples: real cases, enforcement actions, settlement terms give clues about what regulators want.
Creates networking & collaborative learning among companies, labs, attorneys—sometimes leads to shared best practices and improved compliance tools.
Conclusion & Looking Ahead
challenges that remain
Interpretation & consistency: Some parts of the new rules leave room for differing interpretations (e.g. how visible is visible enough in online warnings? how to quantify exposure in some supply chains).
Cost & logistical burden: Relabeling, redesigning warnings (especially for many SKUs or imported goods), and shifting online content all require resources.
Lag in updating supply chains: Suppliers (especially overseas) may not be fully aware or ready for some formatting or chemical disclosure changes, creating risk downstream.
Legal risk premium: With enforcement still active and settlements being public, companies that don’t proactively adapt may face higher penalty risk or more frequent litigation.
For companies doing business in or shipping to California, Prop. 65 compliance is no longer just a “check the box” task. The 2025 amendments, combined with heightened enforcement, make it essential to revisit any warning practices—on labels, websites, catalogs, and in product development.
We expect that in the coming months we’ll see:
More clarity (through enforcement or guidance) about some of the vague or ambiguous areas of the new rules.
Possibly more safe harbor levels or updated lists of chemicals as science evolves.
Increasing focus on online sales and digital disclosures.