they want one that will poison them

Yes, minerals are chemicals. In this case, it’s a marketing distinction between sunscreen that sits on the surface of the skin and blocks sun on the outside, and sunscreen that diffuses into the dermal cuticle before it can reach the living cells underneath. “Mineral” sunscreen is safer for sensitive skin, “chemical” sunscreen is more resistant to water and sweat.

non sequitur; you are using a different senses of both those words than OP, who is using well-established terminology for sun protection.