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Arai helmets are handmade to the highest possible standard, and although after many years the outside shell can look as good as new, it’s the EPS polystyrene liner that loses its ability to absorb impact over time.
Arai recommend replacing your helmet 7 years after date of manufacture and 5 years after date of purchase to maintain the maximum levels of protection.
The EPS liner is effectively the shock absorber of your helmet, absorbing the force of an impact onto the shell. This is done by the cells in the poly styrene being expanded (EPS = Expanded Polystyrene) and filled with air to absorb impacts. Over time, even when not in use, these liners lose their air pockets incrementally, after 7 years, dropping the shock absorbing ability of the liner below Arai’s safety standards. This is why we declare the helmet due for replacement so it can properly protect you against impacts.
Is the production date visible on the helmet?
Researches have shown no evidence of degradation of the materials (used in the helmets manufacture) due to the mere effect of the times passing by. Nevertheless the exposure to the atmosphere agents (extreme hot and extreme cold), and the contacts with the vapors of the lubricants and gasoline normally used in the motor bikers environment may influence the molecular links of the materials used. Moreover, because of its own nature, the helmet often undergo to shocks of different amplitude that could limit its performances. For all these reasons and for the abuse to the comfort padding and for the technical evolution that make more modern and protective lids available, it is suggested to replace the helmet after 5 years of use. In case of intensive use this delay should be shortened accordingly. If a helmet supports a severe blow, even if there is no evidence of damage, it should be replaced.
If it ain't broke, I'll break it.