Last updated on August 31, 2024.

Almost every time I see a Proposition 65 warning label on a product I’m considering purchasing, I don’t buy it. My spouse often asks, “Is it really a big deal?” I say, yes, it means the product has chemicals known in the State of California to cause cancer.
If they cause cancer in California, they cause cancer everywhere.
We’ve had friends over the years who had lived in California. When we asked about Proposition 65, they shrugged and indicated that California’s just ‘overly cautious.’ I quietly disagreed. I didn’t know enough to debate the matter. So I decided I’d learn about it.

“California tends to be the pioneer of protecting consumers from harmful chemicals in everyday products.” – Darin Olein, Fatal Conveniences
Cancer on the Rise
As I was writing this article, a new study came out indicating that Generation X and Millennials have a higher risk of getting certain types of cancer when compared to earlier generations. “Researchers from the American Cancer Society (ACS) studied 34 of the most common cancers. They found that cancer incidence rates continued to rise in progressively younger generations in 17 of the cancers, including breast, pancreatic, and gastric cancers.”2
While that study does not point to a cause, Generation X and Millenials have been exposed to far more chemicals than previous generations. We know many chemicals are linked to cancer,3 so overexposure to those chemicals is an obvious explanation.
Read on to learn how Proposition 65 warnings can help us.

What is Proposition 65?
It is a right-to-know law. The California Office of Environmental Health Hazard Assessment (OEHHA), which administers the Proposition 65 program, defines it as such: “Proposition 65, officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986…requires businesses to provide warnings to Californians about significant exposures to chemicals that cause cancer, birth defects or other reproductive harm.” These warnings can be in products, homes, workplaces, or the environment. It also protects the state’s drinking water sources from being contaminated with these chemicals.4
“A Proposition 65 warning is telling you that using a product or entering a location can expose you to a significant amount of a chemical that causes cancer, harmful effects on a developing baby, or other harmful effects on reproductive health.”5Â
What else does the legislation do?
Proposition 65 requires California to publish a list of these chemicals which must be updated annually. It includes over 1000 chemicals.6Â
For this list, California recognizes the International Agency for Research on Cancer (part of the World Health Organization), the U.S. National Toxicology Program, and the Environmental Protection Agency (EPA) as authorities on carcinogens. The State of California can also make its own determinations about specific substances. As the American Cancer Society notes, “This means that not every chemical on the list has been proven to the worldwide scientific community to actually cause cancer in people.”7Â
But, if certain chemicals are suspected of causing cancer in California, that’s good enough for me to avoid them.
The List
More than one thousand chemicals make a very long list. The Proposition 65 website has a page called “Fact Sheets” that lists chemical groups, rather than individual chemicals, making the risks easier to read and understand. However, it is not nearly as comprehensive so I recommend viewing both. I’ve linked them under Additional Resources below.
The list includes toxic substances such as lead, asbestos, and hexavalent chromium; industrial solvents; and toxins like carbon monoxide and tobacco smoke. It even includes BPA (Bisphenol A), a toxic substance used in plastic and metal can linings; as well as Styrene, used in many polystyrene take-out containers we incorrectly but commonly call Styrofoam.

Proposition 65 Labels
Product labels can be unclear as they only indicate if a product contains chemicals that may cause cancer or reproductive problems. They are required to list one specific chemical in the warning. However, they are not required to list every chemical, their amounts, or how a person may be exposed to them.
“By law, a warning must be given for listed chemicals unless exposure is low enough to pose no significant risk of cancer or is significantly below levels observed to cause birth defects or other reproductive harm.”8Â
Products Sold in Other States
Products sold outside of California are not required to have a warning label even if they contain those toxic chemicals. “Some companies that sell products all over the United States only label those sent to California, even though all their products contain the same compounds.”9 Online sellers to all states must include warnings on their products, such as those listed on Walmart, Amazon, Lowe’s, and others.
Changes Brought by Proposition 65
Many sources don’t find the Proposition 65 warnings helpful, including Wirecutter, the consumer product review arm of The New York Times. I’ve often found their reviews and recommendations helpful because they independently test and review many products. But even they say Proposition 65 isn’t a big deal to worry about because the labels don’t indicate the amount or methods of exposure. However, they do acknowledge that the law has brought change to a variety of consumer products. “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 Coke to change its use of 4-MEI, a potential carcinogen found in some caramel coloring.”10
The law has successfully raised awareness. Here are some of other the changes it has helped with:
“Proposition 65 has helped reduce or eliminate the use of lead in a wide variety of products, including hair dye, toothpaste, ceramic ware, foil caps on wine bottles, children’s jewelry, and even some types of cookies and candy. Levels…with acrylamide levels in major brands of potato chips and french fries. Proposition 65 has also led to the removal of several chemicals harmful to the developing baby during pregnancy from many nail care products, and has encouraged manufacturers of paint strippers to develop alternatives that do not contain methylene chloride or NMP.”11Â
Controversy
Others argue that Proposition 65 is overly cautious, while others believe it is too broad and meaningless. In fact, on a lot of forums, many people completely disregard the warnings. Some say they are on ‘everything in California;’ others indicate that they just don’t think it’s a big deal. One person wrote, “California puts that on literally everything, they’re idiots.” On another forum where someone asked why a golf towel has a Proposition 65 warning, another responded: “We live in an age where it wouldn’t be out of place to put a warning sign on a water bottle saying ‘could cause drowning.’ Don’t think anything of it.”12Â
But do think something of it. That golf towel likely has formaldehyde or PFAS in it, which are toxic. Why are harmful chemicals allowed in our products? The reason is that the amount in each item is often limited, making small amounts in products seem acceptable.
But here’s the thing.
If these chemicals were just in our couches or clothes or shampoo, it would be limited exposure. But they are in EVERYTHING. These chemicals are in our food, make-up, skin care products, shampoo, soap, clothing, furniture, carpeting, vinyl flooring, mattresses, bedding, drinking water, household cleaning products, cookware, vehicles, pharmaceuticals, hair dye, take-out containers, drapery, building materials including windows and blinds, plastic food containers and packaging, camping tents, shower curtains, electrical items…etc. We are surrounded by these toxins in our homes, in our showers, in the workplace, and in our schools. If we encountered a single chemical occasionally, it likely would not pose a significant threat.
But we are constantly bombarded with these chemicals in every facet of our lives. We are inundated with these chemicals and cumulatively, it harms us. This raises our chances for reproductive and developmental problems, cancer, and other health issues such as rashes, headaches, and allergies. This is likely why cancer is on the rise.

Protecting Our Health
We are poisoning ourselves with these toxins. As consumers, we must avoid them whenever possible to protect our health. Let’s refuse to purchase items that contain these harmful chemicals. This collective action will drive companies to make necessary changes.
I hope this information helped! Please check out my next article about products with Proposition 65 warnings. Thank you for reading, please share and subscribe.
Additional Resources:
List, “Proposition 65 List of Carcinogens or Reproductive Toxicants,” Office of Environmental Health Hazard Assessment (OEHHA), State of California, December 29, 2023.
“Fact Sheets,” Proposition 65 website.
Article, “Prop 65 was meant to protect residents from toxic water. How did warning stickers end up on everything?” Vox.com, updated October 31, 2019.
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