never shine a 5mw laser at a moving vehicle, and airplane, or a police officer. Do not stare directly into the laser (short flashes are ok). If you do none of those things it is not dangerous.
A 5mw green laser appears brighter than a 5mw red laser. It is not actually brighter, but our eyes are more sensitive to green light. Class 3b applies to any laser 5mw or less, so yours is 3b.