Toxic Warning Labels On Everyday Products

I must be the last person to have seen these, because the Internet is filled with discussions about them, but the following warning label on a metal vegetable garden sprinkler at a True Value Hardware store in Milwaukee caught my eye:

THIS PRODUCT MAY CONTAIN CHEMICALS KNOWN TO THE STATE OF CALIFORNIA TO CAUSE CANCER, BIRTH DEFECTS OR OTHER REPRODUCTIVE HARM. WASH HANDS AFTER USE.

OK. I can read. It says "may."

It also says "chemicals known."

California has more stringent environmental regulations than does other states, but why would Wisconsinites want to even risk putting known dangerous chemicals on their hands, or the yards on which their kids and pets play, or spray them on their vegetables?