Rules say 100, some other threads say 100 and he was able to login and play yesterday, however a friend of mine got the message he can't use the site because he's under 300 hours.
Steam profile:
http://steamcommunit...561198038401416
Logs from yesterday:
http://logs.tf/10171...561198051993563
His screenshot:
http://i.imgur.com/5sJWp9e.jpg?1