Prop 65 Warning Label Requirements: Do Yours Pass the Test?

The importance of warning labels for businesses


If you’ve spent time in California, then you’ve probably seen Prop 65 warning labels on products or even posted in places like fast food drive-through windows and parking structures. The law requires these labels because they inform consumers about potential exposure to chemicals that can cause cancer. Moreover, this regulation applies to most businesses that sell products in California, regardless of where they are located or where they manufacture their products.

Of course, if your business needs to comply with Prop 65 label requirements, it’s important to ensure you’re meeting the standards to avoid fines. In this article, we’ll guide you on how to determine if your products need Prop 65 labels and introduce some Avery solutions to help you stay compliant.

For instance, we offer waterproof labels that are great for a variety of product labels as well as our UltraDuty® labels that are waterproof, oil, and chemical-resistant. What’s more, their chemical resistance is ideal for beauty, bath, and cosmetic products. Additionally, our TrueBlock® block out labels make it easy to add warning labels to your existing products without having to redo the entire label or packaging.

It’s important to know the difference between waterproof and water resistant labels when you’re labeling products that require warnings. Avery UltraDuty® waterproof labels are also oil and chemical resistant.

What is Prop 65?

Prop 65 is a California law that requires businesses to warn Californians when the business has exposed them to chemicals that can cause cancer or reproductive harm. It began in 1986, when voters passed California Prop 65, officially called the Safe Drinking Water and Toxic Enforcement Act. What’s more, according to the California Office of Environmental Health Hazard Assessment (OEHHA), Prop 65 specifically calls out chemicals in “products that Californians purchase, in their homes or workplaces, or that are released into the environment.”

Historical context

While voters passed Proposition 65 in 1986, public views on water pollution had begun changing after the 1969 Santa Barbara oil spill. That spill also incidentally inspired the first Earth Day. However, in 1984 people discovered that runoff from Silicon Valley electronics was contaminating the groundwater solvents, and this really set the stage for Prop 65 warnings. In fact, only two years later, the voters of California passed the proposition.

Understanding Prop 65 warnings

California Prop 65 Warning

Today, businesses that employ more than 10 people and sell in California are required to provide Prop 65 warnings. One common place you might see a Prop 65 warning is in parking garages in California. This is because vehicle exhaust, oil and fuel leaks, and tire wear particles release chemicals like carbon monoxide and benzene. Both of these chemicals can cause cancer and/or reproductive harm. However, it doesn’t matter if you don’t have a physical business in California. The important takeaway is that if you have more than 10 employees and you sell products in California, you still have to include Prop 65 warnings.

Prop 65 List and Chemicals

The Prop 65 list includes nearly 900 chemicals known or suspected to cause cancer or reproductive harm. Published and reviewed yearly by the OEHHA, the list is available as a 23-page PDF on a dedicated OEHHA.gov portal, which also offers a searchable database for added convenience. Of course, many common products contain chemicals that qualify for the list, both natural and manufactured. When a chemical is on the Prop 65 list, it doesn’t mean the government has banned it, but rather dosage and repeated use can be a concern for some. This is why it’s important for consumers to have the information they need to make informed choices.

For example, you most commonly encounter pulegone, a chemical found in plants like catnip, pennyroyal, and peppermint, in peppermint essential oil. As a result, many essential oil products that you might use daily for long periods of time, such as candles, lotions, and soaps, require Prop 65 warning labels.

Cancer and reproductive harm label

Now, let’s take a look at what exactly Prop 65 warning labels are about. First, cancer occurs when certain genes change, affecting how our cells function. However, some outside influences, like certain chemicals, can also affect how our cells function. Prop 65 warns against chemicals that increase cancer risk with prolonged or excess exposure. Additionally, some chemicals can make it harder to conceive children or contribute to congenital disabilities. Warning labels about cancer and reproductive harm help consumers make informed choices about exposure to those chemicals.

Prop 65 Compliance

Prop 65 label requirements

The Safe Drinking Water and Toxic Enforcement Act (Prop 65) does not give much guidance on the placement or design of Prop 65 labels. However, it does specify that businesses must provide a “clear and reasonable” warning for chemicals on the Prop 65 list. Using a template for Prop 65 warning labels is one very easy way to add the warning when required.

Consequences for non-compliance

Unlike most other safety laws that concern businesses, OSHA does not enforce Prop 65. Instead, it’s enforced through civil lawsuits brought by the California Attorney General. So imagine that you employ 11 people, sell hand cream scented with peppermint essential oil on Etsy, and you deliver nationwide. Imagine that your product does not have a Prop 65 warning label and a consumer in California buys it, uses it, and develops cancer. You can be held liable in court. In such a case, you would generally receive a court order to stop selling in California or add warning labels. You could also be subject to up to $2,500 per day for each violation.

Ensuring Your Products Pass the Test

Quick checklist: Do you need a warning label?

An infographic showing a brown glass bottle with a Proposition 65 warning label, alongside a checklist titled 'Prop 65 Checklist: Do you need a label?' The checklist includes four items: 'Ingredient on the Prop 65 chemical list,' 'You employ more than 10 people,' 'People in California buy your product,' and 'Your business is located in California.' The image also features the Avery logo.

Check the Prop 65 chemical list regularly

Does your product contain a chemical on the Prop 65 list? We recommend that you check the list whenever you are launching a new product. However, you should also check the list at least once a year for newly added chemicals. This is because the OEHHA updates the list yearly, and businesses only have 20 months to add a label after a new chemical is listed.

Best materials for Prop 65 labels

The best materials for Proposition 65 warning labels include UltraDuty® waterproof labels, which are not only waterproof but also resistant to oil and chemicals. This makes them ideal for things containing oils or chemicals, like bath and body products, cosmetics, or food and beverages. Another great option are Avery labels with TrueBlock® technology, which provide full-coverage block-out capabilities. These block-out labels allow you to quickly comply with Proposition 65 regulations by adding a warning label to existing packaging. Instead of having to remove all the old labels, you can place TrueBlock labels over anything because they prevent images, barcodes, and other markings underneath the label from showing through.

Free templates and tools to quickly create labels

As previously mentioned, templates for Prop 65 labels are one of the easiest ways to add the warning to your products. Luckily, Avery Design and Print Online (ADPO) is free, easy-to-use software that includes many free warning label templates. You can quickly get started by browsing warning label designs for custom-printed orders. Once you’ve saved your project, you can even apply the design to other Avery products.


We’ve also rounded up a few templates for the most common warning label sizes. Simply choose the “Customize” button for the size that works for your needs. The template will open in ADPO, and you can start customizing immediately. To use any of the templates below for custom-printed labels, simply use the “Let Us Print for You” button after customizing the design. Then, choose the label material before adding them to your cart.

A brown glass bottle with a black cap featuring a 2" x 2" Avery UltraDuty label with a template that reads: 'WARNING: This product can expose you to alcohol, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov.

Print these yourself on 2″ x 2″ waterproof UltraDuty labels sold by the package (60506). You can also order 2″ x 2″ blank labels by the sheet (94107) in a variety of materials, including waterproof or block out.

A green plastic bottle with a wood-patterned product label. On top of that is a 2" x 4" Avery TrueBlock label that reads: "WARNING: This product can expose you to alcohol, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov."

Use this 2″ x 4″ design on Avery TrueBlock block-out labels, available by the package (18163). You can also order 2″ x 4″ blank labels by the sheet (94207) in various materials, including waterproof or block-out options.

A green candle jar with a gold lid, featuring a Proposition 65 warning label designed with an Avery template and printed on a 1/2" square Avery TrueBlock label. The label blocks out any previous text and reads: "WARNING: This product can expose you to benzene and formaldehyde, which are known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov."

Print this template with Avery 1-1/2″ square blank labels by the sheet (94106) in any material—this includes UltraDuty or TrueBlock.

Mastering Prop 65 warning label requirements

Making sure your products meet Prop 65 label requirements isn’t just about avoiding fines—it’s about protecting your customers and building trust. With hundreds of chemicals on the list, it’s important to regularly check if your products need a warning label and update them accordingly. Using Avery UltraDuty waterproof and TrueBlock labels makes it easy to stay compliant without redoing all your packaging. By taking these steps, you can ensure your products are safe, transparent, and ready to sell in California.

You can find more resources for designing, printing, and upgrading your product labels right here on the Avery blog. We’ve also got tons of inspiration and tips on our Pinterest board for small business. And you can always find new ideas on our Instagram page, or share your own using the #averyproducts.

Author: JoJo Mrgich

JoAnn (JoJo) Mrgich is a copywriter and SEO content writer who began her copywriting career in 2011. A musical theater major at the time, JoJo began writing blog articles, product descriptions, and other online content for a dancewear brand. Since then, she has gone on to write in a variety of fields, from essential oils and natural beauty to fashion and swimwear, finally landing at Avery, which she affectionately calls her "forever home." At Avery, JoJo writes content for the Avery blog, covering everything from organization to party planning, as well as contributing to other online content for avery.com. She is also a technical and content writer for Avery Industrial, where she writes in-depth articles that span a wide variety of topics, from safety compliance to 5S lean practices. In her personal life, JoJo is a big fan of fantasy and science-fiction works such as Lord of the Rings and Star Trek (especially the original series). She also loves going to Disneyland and runs a non-profit social organization of 600 members that brings fans of "nerd culture" together for meet-ups and events in Southern California.