Fabric-covered benches are the most child-safe option, especially if they have rounded corners and cushioning. If fabric is not an option due to cleaning concerns, look for wooden benches with rounded edges and corners.
Tip overs are generally not a concern with benches unless they have tall shelving on top. Benches with overhead shelving should be secured to the wall with anchors. Even if there is almost no chance of the unit itself tipping over, top shelves can wobble and cause objects to fall if the shelf supports are not secured to the wall.
Some benches with storage built into the seats have heavy lids that can pinch children's fingers. Avoid using these benches in areas with toddlers. School-age children can typically be trusted to open and close these benches, but children under 5 should be supervised until they have had some practice.