Juttua Arai kypäristä. http://www.motorcycle-usa.com/320/18453/Motorcycle-Article/How-Arai-Makes-Motorcycle-Helmets.aspx
Helmets are surrounded by myths that cloud ownership, and rules that have been around for longer than helmets themselves. Here are some of the bigger ones the Arai team were happy to shed light on.
Dropping my helmet will ruin it.
This is, according to Arai, simply not true of its products (and I assume any other good quality helmet). Dropping a helmet from your handlebar, or any other similar height may damage the paint and add some scratches, but real damage will not occur.
You can only use a helmet for three years.
In Britain it was once a national rule that a helmet may not be more than three years old as it would no longer do the job. Arai says 10 years for its helmets is a realistic time-frame for a helmet, providing you haven't been playing head tennis with the ground.
Painting your helmet will ruin it... Again, not true. If you choose to use a plastic helmet, then you may well have an issue, but the materials used to make any Arai helmet are unaffected by custom painting.