Contact customer service at those two manufacturers and ask them. Sometimes placing these warnings is a rote CYA action that doesn't really mean anything in particular.

Kwikset is builder grade garbage. Go with a respected brand that makes quality hardware, my preference is Baldwin.

Unless you lick/chew your doorknobs frequently that isn't an issue.

CA products get that warning on nearly everything. Even food at the supermarket!

LOL, I bought a new chrome toilet paper holder yesterday. It has the same warning on it, as you are seeing. I am not going to worry about it, or about my doorknobs either.

Thanks everyone. i know that warning was well intended but I have to ignore it more often than not.

The lead warning probably comes from the brass used in the handsets. The amount present is likely near zero as every manufacturer is trying to get the lead out, but even if it it shows up in trace amounts, I'll bet your California friends require the warning.