Infinity pools are also known as weir edge, vanishing edge or negative edge pools.
Long as the edge of the pool is not a walk-way then it does not need a hand rail or fence. The drop off edge can also provide the 1.2 non-climbable aspect of the pool safety regulations.
An infinity edge pool (also named negative edge, zero edge, disappearing edge or vanishing edge pool) is a swimming or reflecting pool which produces a visual effect of water extending to the horizon, vanishing, or extending to “infinity.
Source : http://swimmingpoolsdesign.blogspot.com