They don't produce any dust at all! If you put the chalk inside the stick it contains, it doesn't break! Just the chalk breaks very easily

Although it is of very good quality and does not dirty the hands, I give it 3 stars only because it took away our faith in cleaning. If you don't clean immediately, it requires scrubbing with soap and cleaner to remove it from doors and tiles.
Update: I am reducing the stars to 2 because it has stained metallic doors (gates, etc.) and it doesn't come off anymore.