Just being on the bike is more of a risk than the type of pedals.

If you don't pedal at cadences that make it hard to keep your feet firmly on the pedals throughout the entire revolution of the crank, then you probably don't need toe clips or clipless pedals.

If you do ride at cadences that you can't keep your feet securely on the pedals, then you might be at more risk for a injury or accident. So if that is you, get some SPD's or SPD-SL's.