The Basics Of Safe Guardrails For Elevated Work Platforms
by MHI Industry Group, RMI (Rack Manufacturing Institute)
To maximize the overhead space in their facilities, many operations utilize elevated work platforms, pick modules, or rack supported platforms upon which workers access stored items. Because they’re working above ground level, it’s important to integrate permanent fall protection—specifically guardrails—around the perimeter of the platform or walkway to prevent those associates from falling over the edge.
Guidelines for the safe design of guardrails are offered in two separate ANSI publications: RMI’s ANSI MH16.1-2012: Specification for the Design, Testing and Utilization of Industrial Steel Storage Racks (section 8.4.3.1) and ANSI MH32.1-2018: Stairs, Ladders, and Open-Edge Guards for Use with Material Handling Structures (section 5), which was developed by RMI in partnership with the Storage Manufacturers Association (SMA).
Both specifications note that guardrails must consist of a top rail, an intermediate rail and posts. The horizontal top rail must be at a minimum height of 42 inches above the floor surface. Further, intermediate rails must be designed to prevent a 21-inch-diameter sphere from passing through any opening. For additional safety, the entire guardrail assembly must be designed to separately resist the force of a concentrated live load of 200 pounds, or a distributed live load of 20 pounds-per-foot.
It’s also important to note the difference between a guardrail and a handrail—two terms that are not interchangeable. Guardrails provide fall protection, while handrails are required on stairways to provide additional stability to persons ascending or descending from one level to another. Handrails can also serve as the top of guarding, as long as their position is between 34 inches and 38 inches from the tread surface and that they are built to prevent a 21-inch-diameter sphere from passing through any opening.
Want to learn more about the design requirements that ensure worker safety on elevated work platforms? The RMI/SMA ANSI MH32.1-2018: Stairs, Ladders, and Open-Edge Guards for Use with Material Handling Structures specification can be downloaded here.
