|I can tell you that if they're blocked, trying to get around the security put in place by the company that:|
a) Owns the equipment you're using at work
b) Owns the network you're using at work
c) Employs you
you are liable to get fired. Since hacking is illegal, you're also liable to get charged criminally.
I can guarantee you, they will be monitoring for people trying to bypass the security so if you do try, expect to get caught.
I highly recommend you stick to doing work at work and surf what you want to on your own time at home on your own equipment