Do all shoes contain toxic chemicals?

So I know this warning is pretty much everywhere in california but I have never seen it on an article of clothing, shoes, etc that I have purchased. I bought these for my daughter at Ross. They aren't a brand name, I googled the brand and not much came up. Anyways, she is super excited to wear them to school tomorrow. I grabbed them and noticed this on the back.

Of course I'd like to avoid as much chemicals, etc with my children and I am pregnant as well.. She does own crocs and I did research and as far as I can tell they don't contain this.. Am I being overly cautious or should I get rid of them? I feel bad but I want to be safe.