Can our current non-profit company allow a paid employee to pick up unpaid internship or clinical hours for their college with us if they are picking up the internship hours during non-scheduled work time and if they are doing the unpaid internship just l

We have several current paid employees who are going to college and would like to complete their internship or clinical with us. The would like to do it during their time off when they are not scheduled to work. They would be doing it in a department separate than the one they work in. They would not be doing the same thing the do when they are getting paid. The would not have the same supervisor. They would not be doing work that normally another employee would be paid to do. We were told that we should reconsider this because we are on thin ice by doing so.