The gel beads in diapers are not toxic as in they will not harm your baby or child when they get onto their skin.
However a baby or toddler or child should not be allowed to put the gel beads in their mouths as ingesting the gel beads in diapers could cause health issues.
The gel beads are a polymer known as SAP or Super Absorbent Polymer.
The gel beads or SAP in diapers is what absorbs the pee and holds it in away from a child or babies skin.
As long as the baby does not eat the gel beads it's not harmful to them if they get the gel beads on their skin.
My own babies and toddlers have gotten the gel beads on their skin and it's never harmed them.
The gel beads just wipe off the skin.