Stair nosing

Nosing is the horizontal, protruding edge of a stair where most foot traffic frequently occurs.

In timber flights, The nosing traditionally projects forward of the riser, the same distance as the thickness of the tread material.

[1] Stair nosing, especially in commercial and industrial settings, are typically fitted with a non-slip surface to increase traction and prevent injury or even death from slips, trips, and falls.

Many states have introduced laws and mandates that require new staircase construction to include an abrasive surface or stair tread to minimize the risk of stairway related incidents.

Perhaps the most recognizable standard in California's Title 24 building code is the need for a slip-resistant tread or nosing that is of contrasting color from the steps.