This year marks the 30th anniversary of California voters’ approval of Proposition 65. Over the past three decades, this landmark law has provided Californians with significant health benefits by reducing exposures to harmful chemicals. Proposition 65 ensures that Californians are informed about potential exposure to chemicals that cause cancer, birth defects, or other reproductive harm.

Proposition 65 does not ban the use of listed chemicals; instead, it is a “right to know” law. In many cases, that knowledge has served as a powerful incentive for businesses to remove listed chemicals from their products, such as lead from Mexican candy popular with children, lead and cadmium from tableware and jewelry, and cancer-causing acrylamide from potato chips. Reformulations can benefit all Californians—and depending on where reformulated products are sold, consumers across the United States and around the world may benefit as well.

In a recent opinion article (“Proposition 65 at 30—Time for a Different Approach,” June 13, 2016), David Fischer makes a number of questionable and unfounded criticisms of Proposition 65. But one in particular – that it fails to provide Californians with adequate information about chemical exposures – is important to address in light of our recent efforts to make Proposition 65 a better vehicle for informed choices and a stronger tool to protect public health and the environment.

The California Office of Environmental Health Hazard Assessment, which compiles the Proposition 65 list, is working to improve Proposition 65 warnings by making them more meaningful and informative. We have proposed that future warnings name at least one specific chemical for which the warning is being provided. The new warnings would also refer individuals to our new website,, for more information about chemicals’ health effects and ways to reduce exposure to listed chemicals.

The recent opinion article stated that the proposed new warnings aren’t useful, but Californians overwhelmingly disagree. UC Davis recently surveyed more than 1,500 randomly-selected Californians to assess the effectiveness of the proposed new warnings. The survey showed 77% found the new warnings more helpful than the existing warnings, and 67% favored warnings that name specific chemicals.

A common complaint about current Proposition 65 warnings is that they don’t identify specific chemicals or their hazards. You have probably seen a sign or label that reads: “WARNING: This product contains a chemical known to the State of California to cause cancer.”

To address this complaint and provide more useful information, the proposed new warnings would name at least one listed chemical. Warnings for consumer products would read like this: “WARNING: This product can expose you to chemicals including [name of chemical], which is known to the State of California to cause cancer. For more information go to”

The website provides information on the use and health effects of chemicals listed under Proposition 65 and ways that people can reduce or eliminate exposure to them. The new warnings would be similar to warnings that are currently provided for Bisphenol A (BPA) under an emergency regulation we recently adopted.

The opinion article also incorrectly stated that “businesses would be barred from providing consumers with factual information that puts warning in context for consumers.” This is not true. Our new regulations make clear that businesses are free to provide additional information in the warning that identifies the source of the exposure or provides information on how to avoid or reduce exposure to the identified chemical or chemicals. Businesses are also still free to provide other information separate from the warning message.

We plan to adopt the regulation for the new warning system later this year. Businesses will have two years to phase in the new warning methods and content, but Californians will likely begin to see enhanced warnings within the next several months. We believe this will benefit all Californians by providing improved information about how to exercise their “right to know” and take steps to reduce their exposures to harmful chemicals.

Lauren Zeise, Ph.D., is acting director of the California Office of Environmental Health Hazard Assessment.