Instead of replacing the helmet which is wastful, can anyone suggest ways (non-toxic glue?) of repairing the padding?
I have had some success in the past with fabric glue.
You need to choose a solvent-based, rather than water-based, glue, and try to avoid having the glue come out at the edges, as it can be rather scratchy when dried. To protect the rest of the helmet, take the pads out for repair, and don't fit them until the glue has fully dried.
It will fail again eventually, but by that time the helmet tends to be getting past its best.