What Is Prop 65? And Why Is There a Warning Label on This Thing I Bought? (2024)

A lot of Wirecutter readers have recently noticed alarming labels on things they’ve bought online, warning against cancer and birth defects. These frightening labels all mention something called “Prop 65.” So ... what is that? And should you actually be scared? Here’s what you should know.

What is Prop 65?

California’s Prop 65, officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986, was a ballot initiative voted into state law more than three decades ago. It was created in reaction to the discovery of dangerous pollutants contaminating the California water supply. The California Office of Environmental Health Hazard Assessment (OEHHA) says Prop 65 “requires businesses to provide warnings to Californians about significant exposures to chemicals that cause cancer, birth defects or other reproductive harm.”

It now extends far beyond drinking water, though. “Businesses” means anyone who sells anything that may cause exposure, above “safe harbor” levels, to a long and growing list of chemicals;California is required to update this list each year. In 1988, when the warning requirements went into effect, the list included 235 chemicals, according to the Los Angeles Times. The list now has about 900 toxins and carcinogens on it. If a product that’s sold in California includes one of those 900 chemicals, it requires the Prop 65 warning label.

Although federal agencies like the Food and Drug Administration and the Environmental Protection Agency already set levels for safe consumption of chemicals, Prop 65 goes above and beyond federal standards, sometimes setting different limits than the EPA does.

If this law is three decades old, why am I seeing so many Prop 65 warning labels only now?

There are two big reasons you see so many labels now: e-commerce and lawsuits.

In August 2018, new OEHHA regulations took effect, requiring websites that sell products that qualify for the warning to include these labels. This is why you may have recently seen more warnings on e-commerce sites like Amazon.

The law also changed the language and look of warnings, which now need to include a warning symbol (a yellow triangle with an exclamation point), name at least one of the chemicals in the product, and provide a link to www.P65Warnings.ca.gov. Most companies provide the Prop 65 “clear and reasonable warning” by affixing sticker labels on products, though some establishments also post signs in, for example, the wine and liquor aisle at the store. Stephen Kam, director of advertising at Smith Corona, a printing company that sells compliance labels, says the company’s seen an increase in requests since the August 2018 change. “You need to put the exact chemical that is related to Prop 65 on your label. Many people just want a generic one, and don’t realize that doesn’t follow the law,” Kam says.

As e-commerce business continues to grow and inventory travels across state lines, we’ve seen more companies put the labels on everything—even on items that aren’t necessarily bound for California—to avoid being sued. A representative of Zojirushi America Corp., which produces several items we recommend (including our favorite travel mug and food thermos), told us that the company labels everything sold in the US and through e-commerce.

Failure to comply can leave a company liable for fines of up to $2,500 per violation per day, according to OEHHA. The labeling onus is on brands and retailers, and court cases have risen as the list of chemicals grows longer. In 2000, there were 200 settlements (PDF) totaling over $11 million, according to the California Office of the Attorney General. In 2018, there were 829 settlements (PDF) totaling more than $35 million.

Should I worry about Prop 65?

Probably not.

The Prop 65 label is like a noisy alarm that rings equally loudly about smaller amounts of low-risk substances and huge amounts of potentially harmful chemicals. The labels don’t say how much of the chemical is present, or how much it would really take to make a person sick. You could get the same alarming label on potato chips (acrylamide), chemotherapy (uracil mustard), lumber (wood dust), or toxic runoff (arsenic). It’s obviously helpful to be alerted to the presence of potentially harmful chemicals. But not all doses of these different chemicals mean the same thing.

Imagine if a warning label accompanied every risk you took on a regular basis, from driving on the freeway to baking gel nail polish under UV light. Fear is powerful, but it should be commensurate with the danger, and the Prop 65 label tends to equalize risk in a way that actually might actively harm people’s ability to judge danger.

At its best, Prop 65 has resulted in changes in product formulation to remove or reduce potentially harmful chemicals, including in things like Wite-out and herbicides. Awareness raised by Prop 65 led co*ke to change its use of 4-MEI, a potential carcinogen found in some caramel coloring.

But these Prop 65 labels can make even low-risk situations seem dicey. The Zojirushi representative explained that the company has the labels for the chemicals used in power cords (bisphenol A), packaging (styrene), and the sticker on the outside of its models (Di-n-Butyl phthalate), but said buyers probably won’t interact much with any of these. “None of these materials come into contact with your food or beverage,” the representative said.

Of course, you may be in less danger with a clearly labeled item than you would be with unlabeled products, even if the overlabeling phenomenon leads to some false positives. Companies that are willing to comply with the law by warning buyers are probably providing safer goods than unknown manufacturers from third-party sellers overseas, since the latter may not be following federal guidelines for safety for things like lead paint or cosmetics additives.

If you want to read more about some of the specific court cases that have changed the course of Prop 65 over time, Vox has a great piece on its impact.

So … what should I do about Prop 65?

If you see a label and would like to understand more, reach out to the company’s customer service to find out what the chemicals in question are, and look up information about their risks from an organization you trust.

For our part here at Wirecutter, we look into the composition of products that might be consumed or put on your body. But we don’t consider Prop 65 regulations, per se.

What other kinds of guidance on Prop 65 issues would be most helpful to you? Let us know in the comments.

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• After testing travel mugs for over 10 years, we’re still confident that the Zojirushi Stainless Steel Mug is the best mug to keep drinks hot for hours. The Best Travel Mug
• We compared 22 food thermoses and tested 10, and we're confident we've found the best one for most people. Read on to see what we recommend.The Best Food Thermos