A stepladder is a self-supporting ladder, non-adjustable in length, having flat steps, a hinged back and a metal spreader that locks the ladder open. They should only be used when all four legs are on a solid, level, non-slippery surface.
Do not use a stepladder if the height you need to reach is three feet higher than the stepladder. You would be forced to stand on the top two steps leaving the base unstable, and potentially causing a fall.
A portable ladder is not a self-supporting ladder, but can be leaned against a wall to reach higher than a stepladder. They should be placed on firm, stable footings and use leg extensions or non-slip feet.
A ladder’s duty rating tells you its maximum weight capacity. There are four categories of duty ratings:
Type III - Withstands loads up to 200 pounds
Type II - Withstands loads up to 225 pounds
Type I Withstands loads up to 250 pounds
Type IA - Withstands loads up to 300 pounds
For your safety, only use Type I or Type IA in the workplace to ensure the ladder will withstand the load. Management will provide you with the proper ladders.