Proposition 65: What It Is, When It Is Needed, Product Categories, Common Mistakes, Business Impact, and Compliance

California’s Proposition 65, formally known as the Safe Drinking Water and Toxic Enforcement Act of 1986, remains a uniquely powerful piece of legislation within the United States. Introduced by popular vote, this law requires clear warnings on products or environments that expose people in California to chemicals known to cause cancer or reproductive toxicity*. As regulatory, consumer, and business landscapes mature, Proposition 65’s reach—and the best practices for its compliance—have only become more significant.

Most savvy business leaders and compliance professionals already associate the law with ubiquitous warning labels. Yet, behind each label is a web of scientific assessment, policy interpretation, and practical decision-making. A thoughtful, compliant approach to Proposition 65 isn’t just a legal safeguard; it can also reinforce a brand’s transparency and social responsibility. Examining its purpose, scope, business implications, and smart compliance strategies reveals a world of responsibility and opportunity.

Defining Proposition 65

Proposition 65 was enacted to address growing public concern about exposure to toxic chemicals. This law obligates California to publish a list of chemicals that are known to cause cancer, birth defects, or other reproductive harm. The list has grown over the years and now numbers over 900 chemicals, encompassing everything from lead and formaldehyde to some pesticides, solvents, and common industrial chemicals.

The heart of Proposition 65 is the requirement that businesses provide “clear and reasonable warnings” before knowingly and intentionally exposing anyone to a listed substance above certain thresholds. These thresholds are referred to as “safe harbor” levels. If exposure to a chemical could exceed these safe harbor thresholds, a warning is necessary.

Two major obligations lie at the core:

• Businesses must not knowingly discharge listed chemicals into sources of drinking water.

• They must also provide warnings for exposures that exceed the designated safe levels.

It is crucial to note that Proposition 65 does not ban or restrict the use of chemicals—it requires disclosure via warnings and is focused on transparency rather than prohibition.

Determining When Warnings Are Needed

The question of when a warning is required triggers frequent debate among industry professionals and regulators alike.

A business must provide a warning if:

• Its product, workplace, or property will expose a California consumer to any listed chemical above established safe harbor levels—either orally, dermally, through inhalation, or environmental contact.

• No explicit exemption applies and the business has ten or more employees.

The frequency of chemical review and additions to the list means regulatory requirements can shift overnight. Companies must stay vigilant by monitoring updates to the Proposition 65 list and updating their own product and materials assessments in parallel.

How Exposure Is Evaluated

Exposure is not just about chemical content. It hinges on the path by which a user, worker, or visitor might encounter the substance and the realistic level of contact. The law differentiates between cancer, reproductive toxicity, and both routes may have different safe harbor numbers (NSRL for carcinogens, MADL for reproductive toxins).

Setting these thresholds involves toxicological risk assessments and, where available, the state publishes safe harbor numbers that businesses can rely on. If no such level is published, companies must make their own risk assessment or provide the warning by default.

Standard Exemptions

Several exemptions exist, including:

• Federal preemption: If federal law dictates warning labels for a chemical, Proposition 65 labeling may not be needed.

• Exposures below safe harbor levels don’t need a warning.

• Chemicals that are naturally occurring in food or cooking processes, provided certain criteria are met.

• Businesses with fewer than ten employees are generally exempt.

Product Categories Under Proposition 65

The reach of Proposition 65 is strikingly broad. Nearly every consumer-facing product can come under scrutiny if it is distributed, sold, or used in California. A snapshot of covered categories demonstrates the diversity:

Even short product lists on e-commerce sites now often carry Proposition 65 warnings next to “Add to Cart” buttons. Many companies adopt online warnings proactively, not just on physical packaging or in California stores.

Chemicals That Trigger Warnings

Although the Proposition 65 list runs to over 900 chemicals, some high-profile substances appear more frequently. These include:

• Lead and lead compounds (common in imported goods, electronics, jewelry)

• Phthalates (plasticizers in vinyls, plastics, latex)

• Bisphenol A (BPA) (found in polycarbonate plastic food containers)

• Acrylamide (formed in some cooked foods)

• Formaldehyde (in pressed-wood furniture)

The chemical and product matrices are exceptionally complex, so understanding the supply chain and material content for each product is critical.

Common Mistakes and Misconceptions

Despite widespread visibility, myths and errors around Proposition 65 compliance remain frequent. These missteps can result in significant enforcement actions. Consider the most common pitfalls:

“Blanket” Warnings

Some businesses, daunted by risk or complexity, simply slap a warning label on each product without assessment. While this might seem “safe,” regulators have stressed this is not the law’s intent. Over-warning may also dilute the strength and meaning behind genuine safety alerts, potentially leading to consumer confusion or litigation risk.

Ignoring the Law or Assuming Exemption

A surprising number of businesses—especially small firms or those located outside California—ignore compliance requirements under the mistaken assumption that state law won’t “reach” them. The nature of modern e-commerce, however, means any direct sale into California triggers duties under the statute.

Failure to Assess Full Product Lifecycle

Chemical exposure is not static; it can change as products age, degrade, or are recycled. Companies sometimes assess materials at the point of manufacture, but ignore how exposure might escalate after years of consumer use, improper disposal, or through off-gassing from packaging.

Misinterpreting Safe Harbor Levels

Calculating whether actual exposure will cross the established safe harbor levels requires technical know-how and scientific modeling. There is a tendency to conflate “chemical content” with “exposure,” overlooking usage patterns, duration, and volume of contact. This is especially relevant to items like cookware, furniture, or children’s products.

Errors and Omissions in Labeling

Requirements for label placement and message wording are specific. Several mistakes crop up repeatedly, such as:

• Warnings that fail to use required language or symbols

• Small or unreadable print

• Not linking online point-of-sale warnings for e-commerce

• Omitting updated warning requirements that came into effect as of August 2018

Overlooking Supply Chain Transparency

Many businesses don’t have granular visibility into the chemical composition of their supplied parts or raw materials. This can result in downstream non-compliance, especially for overseas suppliers with divergent chemistries or documentation standards.

The Business Impact: More Than a Regulatory Challenge

No business leader enjoys regulatory uncertainty. At first glance, Proposition 65 appears to be just another compliance hurdle. A closer look reveals that its impact reverberates across many functional areas, presenting risks and also significant opportunities for growth and differentiation.

Brand Reputation and Consumer Perception

A prominent Proposition 65 warning can be interpreted as a “red flag” for consumers, especially those unfamiliar with the statute’s context. Companies face reputational risk if warnings are seen as admissions of dangerous practices, or—conversely—if activists publicize enforcement actions for non-compliance. However, transparency about compliance can actually enhance consumer trust, positioning a company as ethical and consumer-focused.

Litigation and Enforcement Pressures

One distinct aspect of Proposition 65 is its “private attorney general” provision, allowing private parties to sue any business alleged to violate the law. This has spurred a cottage industry of “bounty hunter” litigation, with settlements reaching millions of dollars annually.

Enforcement actions can target any link in the supply chain, and penalties reach up to $2,500 per violation per day. Most lawsuits result in settlements requiring companies to reformulate products or beef up their compliance and labeling processes.

Burden on Small and Mid-Sized Businesses

While large multinationals often have in-house legal and scientific teams dedicated to Proposition 65, smaller firms must navigate expensive testing, legal advice, and supply chain management. Non-compliance can quickly undermine an entire product launch, even if only a fraction of sales occur in California.

Competitive Advantages of Proactive Compliance

On the positive side, organizations that adopt best practices—rigorous ingredient screening, supplier certifications, continuous monitoring—can realize several business benefits:

• Demonstrate corporate social responsibility

• Anticipate and mitigate regulatory risk

• Differentiate through supply chain excellence

• Avoid costly and disruptive product recalls

A practical commitment to Proposition 65 can build bridges with environmentally and socially conscious consumers, investors, and business partners.

Effective Compliance Strategies

Creating an effective approach to Proposition 65 means blending scientific, legal, and operational expertise.

Stepwise Compliance Assessment

1. Chemical Inventory Review:

   • Map all chemicals used throughout the product lifecycle.

   • Compare ingredients to the current Proposition 65 chemical list.

2. Supply Chain Engagement:

   • Require suppliers to disclose material details and certify compliance.

   • Audit upstream suppliers, particularly for imported goods or complex assemblies.

3. Exposure Modeling and Testing:

   • Where safe harbor levels are available, calculate realistic exposure scenarios.

   • Commission accredited laboratory testing for both raw materials and finished goods.

4. Legal Review and Documentation:

   • Partner with specialists familiar with both scientific risk assessment and state law.

   • Maintain thorough records of compliance efforts, testing results, and decision rationales.

5. Warning Label Management:

   • Follow state-prescribed wording, font size, placement, and online sales linkage.

   • Monitor for label updates required by regulation or enforcement precedents.

Cross-Functional Teams

Effective Proposition 65 compliance requires more than a legal department’s signoff. Companies that thrive bring together:

• Product managers and designers (making early material choices)

• Sourcing and procurement (enforcing supplier certifications)

• Regulatory affairs and legal (managing documentation, policy)

• Quality control and testing labs (ensuring accuracy and recency of data)

• Marketing and consumer relations (responding to public or retailer queries)

Modeling compliance as a living, cross-functional process ensures no step is overlooked.

Technology’s Role

Digital solutions, such as robust supply chain management software or specialized compliance analytics platforms, are increasingly indispensable. These tools enable better data sharing, real-time alerts on chemical list updates, automated risk mapping, and seamless documentation tracking.

Ongoing Education and Monitoring

The chemical landscape shifts steadily. Businesses committed to compliance invest in ongoing education:

• Regular updates from regulatory agencies (such as the California Office of Environmental Health Hazard Assessment / OEHHA)

• Membership in industry working groups

• Attendance at seminars and webinars focused on enforcement trends and technical advances

How to Determine Compliance

Knowing whether a product or employer is compliant isn’t always clear-cut, especially for businesses introducing innovative materials or sourcing from diverse geographies.

Here is a distilled checklist to guide an effective compliance determination:

• Current Chemical List Analysis: Cross-reference product contents against the latest Proposition 65 list.

• Determine Exposure Scenario: Consider all exposure routes for intended and reasonably foreseeable product uses.

• Identify Safe Harbor Levels: Locate any relevant NSRLs (No Significant Risk Levels for carcinogens) or MADLs (Maximum Allowable Dose Levels for reproductive toxins).

• Quantitative Assessment: Use laboratory data or modeled assumptions to estimate maximum daily exposure per user.

• Evaluate Need for Warning: If exposure exceeds safe harbor level, provide warning. Document all rationale.

• Warning Implementation: Adhere strictly to regulatory guidance on warning message, format, and accessibility (including for online sales).

• Document Retention: Keep thorough records of risk assessments, test results, supplier attestations, and compliance actions.

Businesses uncertain about compliance for a complex or borderline case should engage independent laboratories and legal counsel for risk assessment and documentation.

Retailer and Distributor Responsibilities

Direct-to-consumer and retail businesses that operate outside California are often surprised to learn that making products available for California residents triggers Proposition 65—and not just at the point of manufacture. Retailers in California must display shelf warnings or require suppliers to provide notices upstream. Distributors must ensure products are labeled appropriately for all sales channels.

Enforcement Trends and Future Trajectories

As chemical science advances and new compounds become prevalent in manufacturing and packaging, Proposition 65’s reach may increase still further. Regulatory agencies and activist groups continue to scrutinize emerging issues, such as:

• Nanomaterials

• “Forever chemicals” like PFAS

• Biomaterials in medical devices

• Chemicals in cannabis products

The law’s adaptability comes with continual responsibility for monitoring shifts in both the list and exposure science. Heightened consumer awareness also means a single misleading or omitted label can quickly erupt into a public-facing crisis, amplified by digital media and activist litigation.

As sustainability, transparency, and consumer safety become ever more central to both policy and brand reputation, thoughtful compliance with Proposition 65 can be a distinctive asset. With the right information, diligent processes, and genuine communication, businesses can turn what at first appears to be a daunting obligation into a catalyst for trust and long-term value.