Do you have to have a handrail on stairs?
Keeping this in view, do you legally have to have a handrail on stairs?
If your home has three or fewer steps, there's no need to install a handrail. However, homes having four or more stairs must have a rail mounted on at least one side if the stairway is less than 44 inches wide. If one edge of the stairwell is open, that's where the handrail must be.
Similarly, what is the difference between a handrail and a stair rail when are they required? Answer: Section 1926.1052 (Stairways) states: Under these provisions, while construction work is being performed, a separate handrail must be provided if the top rail of a stairway system exceeds 37 inches. Since the top rail you refer to is 42 inches, a separate stair rail would be required.
Also question is, how many steps can you have without a handrail?
To get to your question - the code doesn't refer to the exterior in steps but states from finished floor or platform to finished grade in excess of 30" requires a guard rail. It's with interior they mention any stairway with more than 3 risers (2 steps) will require a handrail.
What can happen if a staircase does not have a hand railing?
In scenario number two, where you do not hold the handrail, a misstep may result in a fatality. Clearly this consequence would warrant taking the risk of infection and holding onto tightly the handrail.