I just was approached by a wonderful junior colleague I have, someone I am really hoping our department can keep, who was very upset about the following. Having proposed some changes to our handbook for the department, another, senior colleague blew up at him in front of the chair. Apparently this has happened at least three times. And that other colleague has certainly blown up at me on numerous occasions. I myself keep a wide berth from him. But what should I advise the junior colleague to do? I don’t want to roil a further outburst from the hornet’s nest. Nor make a big deal. But it’s unacceptable. Really.
Reply 1:
Blowing up (I assume he yelled) at a colleague creates a hostile work environment, is a big deal and should not be tolerated. The victim is a junior colleague without the protection of tenure so I can understand his reluctance to address the senior member on his own. But I know that when I was a junior faculty I, and just about every other junior faculty, was disappointed when tenured faculty didn’t stand up for the most vulnerable members of the department.
On the assumption that you are a tenured member of the department, would you feel comfortable approaching the chair and saying something to the extent that it is unacceptable for colleagues to yell at one another and you would like them to talk to the hostile member? You say that the colleague has blown up at you too and now you give him a wide berth so it seems that you are uncomfortable addressing him yourself, but I think that to fail to address the issue in some way is protective of him, gives the impression that his behavior is not problematic and ensures that it will continue.
–Blue
Reply 2:
I agree with everything Blue says here. It is a really big deal that someone is yelling at a junior colleague. (Also a big deal that anyone is yelling at anyone.) I would encourage you, as the bystander in this situation, to bring this to the chair, and then, if the chair does not take the matter seriously, to take it to the dean.
— Basil
Philosophical Spaces 
It may be that a chat from the chair will suffice to address original poster’s concern, but I suspect that in many cases like this it wouldn’t, so I’d like to add a few thoughts. While sometimes we look the other way when colleagues behave unprofessionally because we tell ourselves that they can’t control themselves, my bet is that this is rarely the case. I suspect that for many cases, the reason why unprofessional behavior continues is because often enough it gets the miscreant what they want. This kind of problem really requires a community-wide refusal to reward misbehavior. In this case, part of the best response would be to make sure Junior Colleague’s proposed changes to the handbook get a serious hearing. That, I suspect, would be more effective than any talking-to a chair or dean could give.