Apple Watch 7 - Prop 65 warning WHY

Why does the apple watch 7 have a prop 65 warning?

Apparently after sitting on the phone for a VERY long time Apple can't answer this question and their support people don't even know what a Prop 65 warning is...multiple people asked me how I'm getting the pop up notification on the watch and one asked if I could read it to them. The other read me what a prop 65 warning is and to "contact the manufacturer directly if you have questions". I'm SO disappointed in Apple, especially being a CA company.