FYI

https://helmets.org/recycle.ht

I guess I'll do what that article recommends:

-Trash the strap

-Recycle the plastic shell and strap lock

-Use up foam as packing foam

Of course the latter suggestion means it will get landfilled elsewhere so that suggestion is not really recycling (much) . 

If you know of any other solutions for disposing ethically of your old helmets please let us know. Thanks