California Proposition 65

California Proposition 65, officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986, requires businesses to provide warnings before knowingly and intentionally exposing Californians to chemicals known to cause cancer, birth defects, or other reproductive harm, unless an exemption applies.

The regulation affects a wide range of consumer products sold or distributed in California, including toys, footwear, apparel, electrical products, furniture, jewelry, food-contact products, and household goods.

Proposition 65 compliance involves identifying relevant listed chemicals, determining whether exposure may occur during foreseeable product use, and evaluating that exposure against applicable safe harbor levels. Laboratory testing can provide analytical data on chemical content when needed as part of the compliance assessment.

California’s Office of Environmental Health Hazard Assessment (OEHHA) administers Proposition 65 and maintains the list of regulated chemicals. Businesses selling products into California should therefore monitor the current list and applicable warning regulations as part of their product compliance programs.

What Is California Proposition 65?

California voters approved Proposition 65 in 1986. The law has two principal requirements:

1. Businesses must provide a clear and reasonable warning before knowingly and intentionally causing significant exposure to a listed chemical.
2. Businesses generally may not knowingly discharge listed chemicals into sources of drinking water.

For consumer-product companies, the warning requirement is usually the most relevant.

A chemical’s presence in a product does not automatically mean that the product requires a warning. Proposition 65 generally concerns exposure to the listed chemical, and OEHHA has established safe harbor levels for many chemicals to help businesses evaluate whether a warning is required.

Businesses with fewer than 10 employees are generally exempt from Proposition 65’s warning requirements, although commercial requirements from retailers, customers, or supply-chain partners may still apply.

What Chemicals Are Covered by Proposition 65?

The Proposition 65 list contains chemicals that California has identified as causing cancer, reproductive toxicity, or both.

Chemicals relevant to consumer products can include:

• Lead and lead compounds
• Certain phthalates
• Cadmium
• Nickel compounds
• Formaldehyde
• Bisphenol A (BPA)
• Certain flame retardants
• Acrylamide
• Chromium compounds
• Certain solvents and other industrial chemicals

The relevant substances vary significantly by product type and material.

For example, lead may be associated with paints, coatings, metal components, ceramics, or plastics. Certain phthalates may occur in flexible plastic components. Formaldehyde may be relevant to some composite wood, textile, adhesive, or resin systems.

This makes material and product risk assessment an important first step before laboratory testing.

Companies managing multiple chemical regulations should also consider requirements such as REACH compliance, which applies a different regulatory framework and should be evaluated separately from California Proposition 65.

Does a Product Containing a Proposition 65 Chemical Automatically Need a Warning?

No.

This is one of the most important points for manufacturers and importers to understand.

Proposition 65 generally evaluates the level of exposure to a listed chemical. The simple detection of a listed substance in a product does not by itself establish that a warning is required.

OEHHA provides two principal types of safe harbor levels:

No Significant Risk Levels (NSRLs)

NSRLs apply to chemicals listed as causing cancer.

When an exposure is at or below the applicable NSRL, the business generally does not need to provide a Proposition 65 cancer warning for that exposure.

Maximum Allowable Dose Levels (MADLs)

MADLs apply to chemicals listed as causing reproductive toxicity.

Exposure at or below the applicable MADL generally does not require a reproductive toxicity warning.

OEHHA has established safe harbor levels for hundreds of listed chemicals.

For chemicals without an established safe harbor level, businesses may need to conduct an exposure assessment using the applicable Proposition 65 regulations and toxicological information.

Proposition 65 Testing Requirements

There is no single universal laboratory test called a Proposition 65 test that applies to every product.

Testing programs should be developed according to:

• Product type
• Materials and components
• Manufacturing processes
• Potential chemical sources
• Applicable listed chemicals
• Consumer use and exposure routes
• Customer or retailer requirements

The laboratory first determines which chemicals are reasonably associated with the materials in the product.

For example, testing a PVC component may involve a different chemical scope from testing metal jewelry, ceramic tableware, textile products, or painted components.

Common Proposition 65 Testing Methods

Different analytical techniques are used depending on the chemical being evaluated.

Lead and Heavy Metal Testing

Lead, cadmium, and other metals may be analyzed using methods such as:

• ICP-MS
• ICP-OES
• Atomic absorption spectroscopy
• XRF screening in appropriate applications

The selected method depends on the product, material, required detection limit, and purpose of the analysis.

Phthalate Testing

Certain phthalates may be relevant to flexible plastics, coatings, inks, adhesives, synthetic leather, and similar materials.

Common analytical techniques include:

• GC-MS
• GC-MS/MS

Products containing PVC or other plasticized materials often receive particular attention during a chemical risk assessment.

Formaldehyde Testing

Formaldehyde testing may be relevant to:

• Composite wood
• Furniture components
• Textiles
• Adhesives
• Resins
• Certain household products

The appropriate testing method depends on the material and expected exposure pathway.

Other Chemical Testing

Depending on the product, Proposition 65 assessment may also involve substances such as BPA, nickel, flame retardants, chromium compounds, or specific solvents.

A risk-based testing plan helps avoid unnecessary testing while providing meaningful evidence for compliance assessment.

Proposition 65 Testing vs Exposure Assessment

Laboratory testing and Proposition 65 exposure assessment serve different purposes.

A laboratory test can determine whether a chemical is present and at what concentration.

An exposure assessment considers how much of that chemical a person may actually be exposed to during reasonably foreseeable use of the product.

This distinction is important because Proposition 65 safe harbor levels are generally expressed in terms of exposure, often as a daily exposure level.

For example, knowing that a product contains a certain concentration of lead does not automatically establish the user’s daily lead exposure.

Additional factors may include:

• Frequency of product use
• Duration of contact
• Chemical migration
• Skin contact
• Ingestion potential
• Inhalation potential
• Amount of material transferred during use

Businesses should therefore avoid treating a laboratory concentration result as an automatic pass/fail determination unless an applicable specification or legally supported assessment framework provides such a threshold.

When Should Proposition 65 Testing Be Conducted?

Testing may be appropriate when:

• A product will be sold in California
• Materials may contain listed chemicals
• Supplier documentation is incomplete
• A retailer requires Proposition 65 verification
• New materials or suppliers are introduced
• Product formulation changes
• A previous product has received a Proposition 65 notice
• Chemical composition is uncertain
• A company needs analytical data for an exposure assessment

Proposition 65 Warning Requirements

When a business determines that a product causes an exposure requiring a warning, Proposition 65 requires the warning to be clear and reasonable.

OEHHA provides safe harbor warning methods and content. Businesses can use these prescribed warning formats to obtain the regulatory safe harbor associated with them. OEHHA also notes that businesses may develop their own warning language, provided it satisfies the legal clear-and-reasonable requirement.

Warnings may need to appear in places such as:

• Product labels
• Product packaging
• Retail displays
• Online product pages
• Catalogs

Businesses selling online therefore need to consider both physical product warnings and applicable online warning requirements.

Proposition 65 Short-Form Warning Changes

Businesses should pay particular attention to recent changes affecting short-form Proposition 65 warnings.

OEHHA amended California’s warning regulations, with the amendments taking effect on January 1, 2025.

Among the major changes, the revised short-form warning format requires identification of at least one listed chemical associated with the relevant endpoint.

Businesses that were already using the previous short-form warning format were given a three-year transition period to move to the revised requirements. The amendments also address online warnings, food products, and specific vehicle and marine-vessel parts.

Companies using Proposition 65 warnings should therefore review their current labels, packaging, websites, and retailer information to determine whether updates are required during the transition period.

Proposition 65 Compliance Process

A structured compliance process helps manufacturers and importers determine whether testing, exposure assessment, warning, or additional documentation is appropriate.

Step 1: Identify Product Materials

Break the product into relevant materials and components.

Examples include:

• Plastic
• Metal
• Paint
• Coating
• Textile
• Leather
• Synthetic leather
• Rubber
• Adhesive
• Wood
• Ceramic

Understanding the material composition helps identify likely chemical risks.

Step 2: Review the Proposition 65 Chemical List

Compare product materials and manufacturing processes against the current Proposition 65 chemical list.

Because OEHHA periodically updates the list, businesses selling into California should maintain an ongoing regulatory review process.

Step 3: Review Supplier Documentation

Request supporting information such as:

• Material declarations
• Safety Data Sheets
• Chemical composition information
• Previous laboratory reports
• Supplier compliance declarations

Supplier documents can help identify risk areas and determine an appropriate testing scope.

Step 4: Conduct Risk-Based Laboratory Testing

Test materials or components that present credible risks for Proposition 65-listed substances.

Testing every component for every listed chemical is generally unnecessary. A targeted testing program provides more useful compliance information.

Step 5: Evaluate Consumer Exposure

If a listed chemical is detected, determine whether the expected exposure exceeds an applicable safe harbor level.

This step may require a qualified toxicologist, exposure assessor, laboratory, or regulatory specialist depending on the chemical and product.

Step 6: Determine Warning Requirements

Based on the exposure assessment, determine whether a Proposition 65 warning is required.

When a warning is necessary, review the current OEHHA warning regulations to ensure the content and method of transmission are appropriate.

Step 7: Maintain Compliance Records

Businesses should maintain records supporting their compliance decisions, including:

• Laboratory reports
• Supplier declarations
• Material specifications
• Exposure assessments
• Product specifications
• Warning decisions
• Label artwork
• Corrective actions

Good documentation becomes particularly important if the company receives a Proposition 65 notice or customer compliance inquiry.

Common Proposition 65 Compliance Mistakes

Several mistakes regularly create unnecessary compliance risk.

Assuming a Chemical Detection Automatically Requires a Warning

Proposition 65 focuses heavily on exposure. Chemical concentration and consumer exposure need to be evaluated correctly.

Using a Generic Test for Every Product

Different materials present different chemical risks. Testing should reflect the actual product construction.

Relying Only on Supplier Declarations

Supplier declarations provide useful documentation, although laboratory verification may be appropriate for higher-risk materials or products.

Using Outdated Warning Labels

OEHHA’s warning regulations have changed. Businesses using short-form warnings should review the 2025 amendments and transition requirements.

Ignoring Online Sales

Applicable Proposition 65 warning requirements can extend to internet and catalog sales. Companies selling products through e-commerce platforms should include online sales channels in their compliance review.

Failing to Monitor the Chemical List

The Proposition 65 chemical list changes over time. Newly listed chemicals generally trigger warning obligations after the applicable statutory period. OEHHA continues to publish chemical listing and regulatory notices.

Proposition 65 Enforcement and Penalties

Proposition 65 may be enforced by the California Attorney General, district attorneys, certain city attorneys, and private parties acting in the public interest.

According to OEHHA, penalties for violations can reach $2,500 per violation per day.

Private enforcement is a particularly important feature of Proposition 65. Businesses may receive a 60-day notice of violation alleging that a product exposes consumers to a listed chemical without an appropriate warning.

For importers and brands, maintaining test reports, exposure assessments, supplier documentation, and compliance records can therefore be important when responding to potential claims.

Proposition 65 Testing for Imported Consumer Products

Products manufactured outside the United States can still fall within Proposition 65 when they are sold or distributed in California.

Importers should communicate California chemical requirements to suppliers during product development and sourcing.

For higher-risk products, compliance controls may include:

1. Material specifications
2. Restricted substance requirements
3. Supplier declarations
4. Laboratory testing
5. Production monitoring
6. Finished-product verification
7. Documentation retention

Chemical compliance should also be coordinated with the product’s other applicable U.S. requirements.

Does a Proposition 65 Warning Mean a Product Is Unsafe?

A Proposition 65 warning does not by itself establish that a product violates a safety standard or is unsafe.

OEHHA explains that a warning indicates that the business knows or believes an exposure to one or more listed chemicals is occurring. Proposition 65 warning thresholds and requirements operate under California’s specific regulatory framework.

This is also why businesses should carefully evaluate whether a warning is actually required. OEHHA discourages unnecessary warnings and recommends appropriate professional assessment where the exposure level is uncertain.

California Proposition 65 Compliance Checklist

Before selling a consumer product in California, businesses should confirm:

• Product materials and components have been reviewed
• Relevant Proposition 65 chemicals have been identified
• Supplier chemical documentation is available
• Higher-risk materials have been tested where appropriate
• Laboratory results have been reviewed correctly
• Applicable NSRLs or MADLs have been considered
• Exposure assessment has been conducted where necessary
• Warning requirements have been determined
• Current warning format requirements have been reviewed
• E-commerce warnings have been addressed where applicable
• Supporting compliance records are maintained

A structured process helps reduce unnecessary testing, incorrect warnings, and avoidable regulatory risk.

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California Proposition 65 compliance requires a clear understanding of product materials, relevant listed chemicals, and potential consumer exposure. Laboratory testing, supplier documentation, and exposure assessment can provide the evidence needed to determine whether applicable safe harbor levels are met or a warning is required.