Making coffee at work

At work if non Jewish co-worker(s) make coffee can one also make or have made coffee for oneself if the ingredients are Kosher? Can one rely on it or the fact that it’s open poses a problem?

I’m not sure I understand the first question. If the ingredients are kosher what is the issue?
The fact that its open doesn’t create a problem.

Thank you. The issue is the fact that it’s open. You answered it now. Toda