Whether a harness is required when using a step ladder depends on the specific regulations and the height of the ladder.

In some jurisdictions, fall protection is required when working from a portable ladder if a worker may fall 3 meters or more [1]. However, this requirement may not apply while the worker is moving up or down the ladder [1]. Additionally, if it is not reasonably practical to use a personal fall arrest system, a worker may work from a portable ladder without fall protection if the work is a light duty task of short duration, the worker's center of balance is maintained, and 3-point contact is maintained [1].

For scaffolds, employees more than 10 feet (3.1 m) above a lower level must be protected from falling 6, 18. Acceptable fall protection methods include personal fall arrest systems or guardrail systems [2].

It is important to consult the specific regulations applicable to your location and work environment to determine the exact requirements for harness use on step ladders.