A:Answer It seems in California most everything might potentially cause cancer in a high enough dosage. California law requires that warning no matter how slim or unproven the connection to it causing cancer is, even if the amount of material needed to pose even a slight risk far exceeds the amount of material in the device. The end result is people don't know what warnings in CA are actually credible. Case in point, coffee. Starbucks has small signs posted with this warning in CA.