HELMET TAKING A 'HIT'

[Kokdjembe]

I accept the cautious rule of retiring a helmet immediately after it took a 'hit'. But yôh is, helmet falling from your bike's seat a catastrophic hit which calls for replacement. Or if you fall/crash on a sand track falling yourself into a hick-up on sand, would you retire your helmet?
Is there any way of checking the 'post hit' safety of a helmet? Or do I rather stick to the rule 'eerder bang Jan as dooi Jan'?

 

[silvrav]

 

[Rufus115]

 

[Bill the Bong]

 

[Dwerg]

 

[Welsh]

 

[2StrokeDan]