Can't tell if they are safe to delete, not knowing what these files are.
If they have been in the recycle bin for a while, and your system has had no problems, then I would be fairly sure it would be ok to delete.
P.S. If you are getting rid of old junk,i.e. mp3's videos etc, press the shift key at the same time as the delete tab, and this will delete the file without sending it to the recycle bin.