helmet issues

[Sabre484]

My son rides with me once in a blue moon. His helmet is mostly in the cupboard in his room. The rubber on the bottom started to splinter and break.

Any thoughts as to the possible cause? Is this fixable or should I just buy him a new lid?

I'm resizing the pics and will upload soon.

 

[Sabre484]

 

[luv2ride]

 

[T Rex]

 

[Sabre484]

 

[Buzzlightyear]

 

[Mudslinger]