Hi, Katsname. What you describe can just as easily be borderline personality disorder, which superficially resembles bipolar, but is connected with unpredictable and explosive behavior - sweet and sunny one minute, a raging volcano the next. Those within close proximity describe getting along with someone with borderline as akin to walking on eggshells. The explosions come out of the blue, for no apparent reason. In bipolar, by contrast, bad behavior tends to be tied to mood cycles, so you tend to see it coming.

But you needn't concern yourself with distinctions. A toxic individual who makes life hell for all concerned needs to be dealt with, and it's in the company's interest to act if the behavior affects workplace productivity.

Whatever it takes to get the attention of management - do it.

In the meantime, both bipolars and borderlines are extremely vulnerable to stress. So, whatever you and colleagues can do to make the person's surrounding less stressful will make everyone else's life less stressful. Take careful note of what pushes this individual's buttons - and don't push them. Never - ever - back the person into a corner. I think you get my drift.