It is usually safe to say that hitting a fellow employee is a crime in any state. For example, if you poke the guy with your finger to make a point, it can be considered battery.
As with many things in law, the best answer is "it depends". For example, did you have consent to whack the guy. Were you defending yourself? Were you defending someone else? Remember, words alone, no matter how insulting or provocative, do not justify an assault or battery against the person who utters the words.