Ceramic tiles itself is non-toxic, and often it's installation is a non-toxic process as well.
This is an example of a tile product,

#Vinyl_flooring, total thickness 5mm with 0,5mm overlay(LVT) in wood optics
EL LOC locking system (Välinge)
Abrasion class 33
Embossed
Virgin PVC
Intensified with glass fibre for a better structural stability
Plank size: 5 x 146 / 183 x 1210 / 1220mm
Bevel: 4 sides