Minecraft wiki entry for Damage, associated text: Blocks that are transparent or do not fill an entire block do not cause damage. This includes amethyst clusters, anvils, bamboo, banners, beds, bells, brewing stands, cakes, cauldrons, chains, chests, chorus flowers, chorus plants, cocoa beans, comparators, composters, daylight detectors, dragon eggs, enchanting tables, end portal frames, ender chests, fences, fence gates, flower pots, glass, grindstones, heads, honey blocks, hoppers, iron bars, leaves, lecterns, lightning rods, extended piston heads, repeaters, saplings, slabs that are not double, stairs, stonecutters, trapdoors, and walls. Despite being fully to partially transparent, barrier blocks, beacons, ice blocks, slime blocks, and spawner blocks CAN cause suffocation. Dirt path blocks and farmland can also cause suffocation, regardless of them not being full blocks.