I have recently been asked about use of exercise balls at work stations. Exercise balls require that abdominal muscles be engaged. They are fine for short periods of time (an hour a day, maybe), but should not be used for extended periods (so, no ball chairs). If you get distracted and do not engage the abdominal muscles, you can lose your balance. If you use the ball for too long your muscles will fatigue.
Another concern with them is the height issue. They are not adjustable like a chair, so the height likely will not be appropriate for the workstation. If the recommendation to use one comes from a physical therapist or MD they need to also address the other issues (height, trip hazard, etc.). If the height is right for the work surface and it can easily be stored out of the way and only used for short periods of time, then the use of the exercise ball for sitting might be acceptable. Those are a lot of ifs.
At home, most people are not required to be at their desk or computer for extended periods, as they would be at work. That is why they are better suited for home use.