That is what we have regulations for.
Do you know and understand what is in your shampoo bottle? What a car needs to come equipped with, not just in obvious safety features but also in its deeper and detailed implementation, to be safe for normal use ("normal use" itself being something you get taught in driving school)? How to build your own house, or even just how to recognize that a building you enter will not fall down onto your head?
I, for myself, am very glad that regulations allow me to just assume certain ground truths in avoiding negative impact, without having to be an expert in every little thing that touches my life.