Everything gives you cancer (in California)

What does an extension cord, a trip to Disneyland, and serving of spinach have in common?

Apparently, they can give you cancer. At least in California.

California’s Proposition 65, also called the Safe Drinking Water and Toxic Enforcement Act, was enacted in 1986. It is intended to help Californians make informed decisions about protecting themselves from chemicals known to cause cancer, birth defects, or other reproductive harm. As part of the law, the state is required to publish a list of chemicals that are “known to the State of California to cause cancer or reproductive toxicity.” Products that contain amounts of these chemicals above the limits set by the state must have an attached warning label, the infamous ‘this product contains an chemical known to the state of California cause cancer.

One of the interesting aspects of Prop 65 is how different it is from all of the other national standards set by organizations such as the FDA and EPA. Prop 65 is significantly more strict. Although well intentioned, there are serious problems with this statute. Let’s take a look at just two of the chemicals singled out for required warning labels.


Our first chemical is acrylamide, which a rodent study pinned as a possible carcinogen. It’s found in almost everything that’s cooked at a high temperature. And because a particularly litigious law firm recently sued the state for not properly warning residents about acrylamide in coffee, California is now on the verge of requiring all coffee shops and manufacturers to include a warning on the beverage that it may cause cancer, despite the fact that many of the newer studies link coffee drinking to a lowered risk of some types of cancer, including prostate cancer, liver cancer, endometrial cancer, and some cancers of the mouth and throat.[1]


The Prop 65 Safe Harbor maximum allowable dose level for lead is 0.5 micrograms per day, but the FDA daily limits are set at 75 micrograms for adults and 6 micrograms for children.

According to the EPA, natural levels of lead in soil can range from 50 parts per million (ppm) to 400 ppm. These levels naturally get incorporated into any vegetation that grows in them. Green beans contain 28.75 micrograms of lead in a one cup serving, which is an exposure of approximately 50 times the allowed Prop 65 levels. Spinach contains approximately 5.2 micrograms of lead in a typical adult serving size which is an exposure that exceeds Prop 65 levels by 10 times.

So why don’t we see Prop 65 warnings on our vegetables? That’s because of the ‘naturally occurring exemption’ under Prop 65 that provides that “human consumption of a food shall not constitute an ‘exposure’ for purposes of [Proposition 65] to the extent that the person responsible for the exposure can show that the chemical is naturally occurring in the food.” The 0.5 micrograms per day safe harbor limit applies uniformly to products sold in California, whether the product is a extension cord, a leather handbag or a nutritional supplement.

So, a bowl of spinach does not require a Prop 65 warning, but as soon as you make a supplement or market a smoothie containing it, you’re selling a product that contains a carcinogen.

Risks and consequences

This regulation disproportionately impacts sections of the economy, such as food and supplement manufacturers. For example, while an extension cord manufacturer can source a parts supplier who uses no lead in their wiring, nutritional supplement makers can at best only reduce lead, but cannot completely eliminate lead given its natural occurrence in the ecosystem.

Finally, and perhaps most significantly there is the risk of ‘warning fatigue’ due too the incredible overreach of Prop 65: The more ubiquitous and generalized disclosures become, the less effective they are. Thus while it is critically important to warn consumers about serious health risks, we should not extend this campaign to hypothetical ones. Proposition 65 is not accomplishing that, and by anesthetizing people to the real threats, it may in fact be doing more harm than good.