How Prop 65 Impacts the Adhesives Industry

If you manufacture, sell, or purchase certain products in California, you’ve most likely encountered California Proposition 65 (Prop 65). It is an evolving regulation that is updated as new guidance becomes available, which can add complexity for manufacturers and downstream users.

Recently, vinyl acetate was added to the Prop 65 list, requiring businesses to provide "clear and reasonable" warning labels on products across multiple industries, including adhesives. Regulatory updates of this nature present an opportunity to provide clarity, context, and transparency without losing sight of performance, safety, or product integrity.

This article breaks down what Prop 65 is, why vinyl acetate warnings may now appear on some adhesive labels, and what this means for manufacturers using water-based adhesive technologies.

What is California Proposition 65?

Officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986, California Proposition 65 is a chemical disclosure law administered by the Office of Environmental Health Hazard Assessment or OEHHA, a branch of the California Environmental Protection Agency, or CalEPA.

This regulation requires businesses to provide a clear warning before individuals are exposed to chemicals identified by the State of California as known to potentially cause cancer, birth defects, or other reproductive harm. Prop 65 applies to products sold or distributed in California, including products sold online or through interstate commerce when California consumers may be affected (Proposition 65 Warnings, n.d.).

Vinyl Acetate Added to Prop 65 List

Vinyl acetate is a common chemical ingredient used across numerous industries, including adhesives, coatings, packaging, and textiles. In water-based adhesive systems, vinyl acetate is usually polymerized during manufacturing to form stable, high performing adhesive technology.

With the disclosure requirement in full effect January 3, 2026, OEHHA’s CIC meeting named vinyl acetate as a substance listed under Prop 65 when exposure thresholds are exceeded in product formulations. As a result, updated labeling or documentation referencing vinyl acetate may now appear for certain product applications or distribution channels within the adhesives industry.

This regulatory update is limited to disclosure requirements only and does not mandate changes to:

• Product formulations
• Manufacturing processes
• Performance characteristics
• Application methods
• Handling or storage practices

‍

Understanding Prop 65 Listed Chemicals

A chemical's inclusion on the Prop 65 list does not prohibit its use. Products containing listed substances can continue to be sold and used provided that appropriate warnings are given when required, based on exposure potential and established "safe harbor" levels such as No Significant Risk Levels (NSRLs) or Maximum Allowable Dose Levels (MADLs).

A recent information letter published by OEHHA on December 23, 2025, clarified that the listing applies specifically to the vinyl acetate monomer, not the polymers or copolymers made from it. Residual unreacted monomer in products may be the relevant exposure source for determining if a warning is needed. OEHHA is working to establish a No Significant Risk Level (NSRL) for vinyl acetate and is expected to formally publish additional guidance later this year.

Key takeaways outlined by OEHHA:

• Prop 65 is a right-to-know regulation, not a product safety ban
• Warnings are required when listed chemicals may result in meaningful exposure
• The Prop 65 chemical list is updated regularly based on scientific evaluation
• The presence of a warning does not indicate that a product violates OSHA or federal safety standards

‍

How This Update Affects Manufacturing Operations

For many adhesive applications, particularly in woodworking and laminating, the glue line is not exposed in the finished product. In most adhesive formulations, vinyl acetate is not an intentionally added ingredient but rather a reacted, bound component within the polymer structure. The presence of this material in most adhesive formulations is due to residual, unreacted vinyl acetate, as no chemical reaction achieves 100% conversion. As a result, the potential for exposure during normal handling, application, or end use is minimal. Manufacturing environments also operate under established industrial hygiene practices and safety controls designed to limit employee exposure well below applicable regulatory thresholds.

Key takeaways of vinyl acetate impact:

• Exposure to vinyl acetate in finished goods is often minimal or non-existent under normal use conditions.
• Proposition 65 warning determinations are exposure-based and must be assessed on a case-by-case basis.

_{For more information or assistance, or to be connected to our regulatory team, reach out to customer service at 1.800.487.4583, or via email at IASCS@franklininternational.com.}

Industry Perspective on Vinyl Acetate

Water-based vinyl acetate and vinyl acrylic adhesives are widely used and researched by product development chemists in the adhesives industry. Compared to other technologies, these formulations offer operational and regulatory advantages, including:

• Lower volatile organic compound (VOC) content
• Nonflammable formulations
• Handling characteristics that align with standard industrial safety practices
• Simplified cleanup and storage procedures

‍

Alternative adhesive chemistries, such as solvent-borne or hot melt adhesives, can potentially present higher VOC levels, flammability considerations, or additional handling requirements. Water-based vinyl acrylic adhesives provide a balance of performance and operational manageability while maintaining adherence to regulatory and workplace safety standards.

Commitment to Regulatory Compliance and Transparency

Regulatory compliance remains a critical component of product stewardship and supply chain transparency. Label updates associated with Prop 65 do not alter product performance or characteristics, and are intended solely to align with evolving California disclosure requirements. Additional information is available through California’s Office of Environmental Health Hazard Assessment (OEHHA) via the official Prop 65 Warnings website.

Your Partner in Safe, Efficient Adhesive Application

Franklin International encourages customers to evaluate adhesive application processes with consideration for health, safety and product stewardship. Support resources include training, product literature, SDS documentation and direct assistance from our technical support, customer service, and product safety teams. Reach out to our team today to request any technical documents or product information.

We're Here to Help!

Our team of adhesive experts are at the ready to answer your questions. Contact our technical service team or submit a request for more information. To be connected to our regulatory team, reach out to customer service at 1.800.487.4583, or via email at IASCS@franklininternational.com.

Let's Stay Connected

Stay connected with us on LinkedIn, and don’t forget to check out the Newsroom for all the latest updates on upcoming shows, industry insights, and more.

_____

Franklin Adhesives & Polymers, a division of Franklin International, delivers innovative wood adhesives, specialty polymers, and pressure-sensitive adhesive solutions trusted worldwide since 1935.

About Franklin International: Established in 1935, Franklin International is among the largest privately held manufacturers of adhesives and sealants in the U.S. Headquartered in Columbus, Ohio, the company maintains multiple manufacturing and distribution locations in the U.S. and a plant in Guangzhou, China. The company maintains two divisions: Franklin Adhesives & Polymers provides pressure-sensitive adhesives for labels, tapes and graphics applications, and adhesives for wood assembly markets, and the Construction Division manufactures Titebond-brand wood glues, construction adhesives, sealants and flooring products.

* Disclaimer: Proper adhesive storage, use, and manufacturing processes are required. Residual monomer levels can vary by formulation, curing conditions and product content during the manufacturing process. Users are strongly encouraged to conduct thorough testing under actual use conditions to ensure the total construction meets these requirements. No warranty is expressed or implied regarding fitness for a particular purpose or application. This content is for informational purposes only and does not constitute legal advice. You should consult a qualified attorney for advice specific to your situation. We are not responsible for any damages or losses arising from your use or reliance on the information provided.

References

Proposition 65 Warnings. (n.d.). About Proposition 65. State of California. Retrieved December 19, 2025, from https://www.p65warnings.ca.gov/about-proposition-65