I have been struggling with a pinched nerve in my neck for two months. Getting sleep with a nerve issue while waiting for a date for a surgical repair has been difficult, to say the least. My wife ordered herbal gummies from a California company, and when it arrived, I noticed a Proposition 65 (Prop. 65) warning label staring right back at me.

Prop. 65 is a law requiring businesses to warn California consumers about exposures to products and chemicals identified by the state of California to cause cancer, birth defects, or other reproductive harm.

Exposure to any of the more than 800 chemicals listed under Prop. 65 requires a warning label, which has resulted in warnings on everything from amusement park rides to alcohol. The warning has become ubiquitous to the point of invisibility—after all, when everything has a warning label, nothing has a warning label.

Prop. 65 warnings do not appear to change purchasing behavior, and some argue they actually devalue the impact of more specific warnings on products that may actually be harmful. The law was originally created in 1986 to protect Californians, but who does it benefit now?

A lucrative cottage industry has emerged with attorneys dedicated, almost exclusively, to filing Prop. 65 lawsuits “in the public interest.” Citizen prosecutors have filed more than 30,000 violation notices since the law went into effect, taking full advantage of the legal burden of proof falling on defendants.

Businesses cannot afford to test all of their products for all 800 chemicals listed under Prop. 65, and have been forced to pay more than $370 million in settlements since 2000. Importantly, attorney fees appear to account for nearly three quarters of all the money paid out in these settlements.

Some companies have simply added Prop. 65 warnings to their products to reduce their exposure to potential litigation. Excluding the label is just too risky—penalties for failing to provide warnings can be up to $2,500 per violation per day. Others have stopped delivering products to California entirely and are focusing their online sales to other states.

Despite concerns over Prop. 65’s unintended consequences, the list of chemicals keeps growing. In March, California announced its intent to list perfluorooctanoic acid (PFOA) as a carcinogen under Prop. 65.

PFOA is one of thousands of man-made chemicals known as per- and polyfluoroalkyl substances (PFAS), which are used in a wide range of products. While some PFAS are widely used, U.S. manufacturers have phased out the use of PFOA since the 2000s. Much of the concern regarding PFOA carcinogenicity is based on animal studies with exposure levels much higher than the general population and are generally inconsistent with findings from human epidemiology studies. Therefore, the human health effects of low levels of PFOA remain uncertain and more research is needed.

To date, PFOA has not been proven to cause cancer in humans. The Environmental Protection Agency has stated there is “suggestive” evidence of carcinogenicity of PFOA in humans, based largely on findings from animal studies. As recently as 2020, the European Food Safety Authority found “insufficient support for carcinogenicity of PFOS and PFOA in humans.”

PFOA has been listed under Prop. 65 as a developmental toxicant since 2017. However, classifying it as a carcinogen will likely open the door for a whole new wave of lawsuits in the future as consumer product analytical methods improve that will result in more expensive settlements, higher prices for consumers, more Prop. 65 warnings, and more companies moving away from California. Imagine that level of economic damage inflicted without a thorough review of the evidence and in the absence of conclusive scientific answers on the risks of exposure to PFOA. Now that’s something to lose sleep over.