Yes, you may also control your campaigns with reactive blocking (blocking domains after seeing where ads were served) and proactive blocking (uploading a list of blocked domains before your campaigns goes live). Learn more at http://listenloop.com/brand-safe-ads
You can find the blocked sites under Brand Safety:
In impression log page, you can also add sites into your blocked list by clicking block button at the end:
Please let us know if you have any questions. Our support team will help you quickly.