Another available crib type is the drop-gate crib, where a part of the crib side folds down to allow as much access as a drop-side crib would. The hardware and mechanism in a drop-gate crib is simpler than a drop-side crib, though, so there isn't as much risk of mis-assembly or of the hardware failing and posing a serious safety problem. The horizontal bar through the crib's side, created by the drop gate, can give industrious toddlers a foothold for climbing out, though. For now, I think the best option is a stationary crib with no moving sides or gates.
To prevent head entrapment and suffocation between the mattress and crib sides, a mattress used in a full-size crib must be at least 27 1/4 inches x 51 1/4 inches, with a thickness not exceeding 6 inches. The assembly instructions, the retail carton for the crib, and the crib itself must contain a specific warning statement that notes these dimensions.
My best friend is the cautionary tale in this department. She decided she no longer enjoyed staying in her crib when she learned to pull herself up and began walking. She then began jumping in her crib—jumping so high that she propelled herself out of the crib. YouTube is of tiny escape artists climbing out of their cribs, over baby gates, up walls, and onto pantry shelves. If a child wants to try something badly enough, she will accomplish the task—no matter how tall the baby gate or crib side.
The standard is published in the Code of Federal Regulations at . The standard incorporates by reference , with two differences. First, the CPSC's standard excludes the provision in section 6.12 of the ASTM standard that requires retightening of screws and bolts between the crib side latch test and the mattress support vertical impact test (§ 1219.2(b)(1) of the CPSC's standard). Second, the CPSC's standard adds a sentence to section 7.7.1 of ASTM F 1169-11 to clarify how to conduct the spindle/slat static force test with a crib that has folding or movable sides (§ 1219.2(b)(2) of the CPSC's standard). The specific requirements and descriptions of the tests for full-size cribs are in ASTM F 1169-11, which can be purchased from ASTM.