If a helmet has been subjected to an impact it is likely that the energy absorption properties of the helmet would have been damaged. If this is the case, it is likely that the helmet would offer a reduced level of protection to the wearer’s head if it should be subjected to a further impact in another accident.
You may wish to note that the damage sustained in the original impact may not be visible. Therefore, we would always advise that if a helmet has been subjected to an impact, it should be replaced to ensure the wearer is suitably protected in the event of an accident. You may also wish to consider seeking advice from the helmet manufacturer.