There is always a risk when you run your computer components above factory spec. However, with knowledge and understanding you can probably find a safe OC.
Example: my C2D E8200 has been happily running @ 3.6 vs 2.6 stock speed for over 2 years now. I did plan this build for OC'ing, so I have the proper cooling and hardware to support a 1 GHz increase in speed.