How loud is too loud for my ipod?

I usually don't go over 2/3's but sometimes that isn't loud enough.How loud is too loud for my ipod?
If you go over 2/3 max volume, for 1hr +, daily or often, by the time you hit 30, your gona get ear problems. Statistically proved, scientifically proved.
if you want it loud and it isnt loud enough dont blame urself if you cant hear any more
As a hearing Doctor.
I can hear just fine having the volume going up less than 1/3 of the way, and thats with people talking in the store or the noise in the mall, if you cannot hear, which many band members and rock crazy or rock concert crazy people have experienced, then stop listening to loud, when im like 60 i will see everybody having hearing aids..
It varies for each person, really. However, unless I really feel in the mood to blare my music, I just keep it quiet enough that people around me can't hear it.
Contrary to what the guy up there says, there isn't set number that is going to cause ear problems because there haven't been any 30 year long studies.
However, there isn't to keep it so loud that everyone around can hear it. Its for you.
By the way, I'm referring to headphones that go inside your ear. The little ones.