The California Safe Drinking Water and Toxic Enforcement Act of 1986, also called Prop 65, is an initiative that addresses citizen concerns about toxic chemical exposure.
What you are seeing is a common California Proposition 65 warning to inform residents of California about exposures to specific chemicals, in this case lead.
The lead limits set by the government of California are the strictest in the world. 25 times lower than the FDA.
The presence of this warning does not mean the product is unsafe.
Alternatively, a product without this warning does not necessarily mean the product is safe.
It is important to remember that almost all of the foods we eat on a daily basis contain very minuscule amounts trace elements, including heavy metals. Mushrooms, like any other naturally grown fruits and vegetables, will absorb minerals and heavy metals from the substrate or soil in which they are grown.
For more information about this warning, please read our detailed article which contains heavy metals testing data as well as how it compares to common every day foods.
At Real Mushrooms, your health and the safety of our products is a primary concern and for this reason, every batch we make is tested extensively in order to meet all regulatory requirements, including heavy metals. Our products are consumed by tens of thousands of people daily and are recommended by thousands of health practitioners.