I tried adding the apps.facebook.com in content and it did not work. Please any ideas?
Facebook tries as hard as it can to make such things impossible.
Same for “logon using facebook”. You “cannot” block general facebook access while still allowing users to
logon to other services using their Facebook account. It would have been easy for Facebook to allow that by
using different domain names for different functionality, but they don’t do that for a reason: by making sure
that they are important to allow (to be able to use lots of useful services) they make sure that they don’t get
arbitrarily blocked by overzealous admins/companies.
That just sucks balls 
Then how do I stop employees from playing facebook games all day. The company uses facebook so I cannot block facebook itself.
Tell them that they can’t work in this company if they play games 
Sometimes this is more effective.