1. Any working surface 4 feet or higher must be protected with guardrails on all sides at least 42″ tall and have to withstand 200 pounds of force.
OSHA 1910.29(b)(1): The top edge height of top rails, or equivalent guardrail system members, is 107 cm, plus or minus 8 cm, above the walking-working surface. The top edge height may exceed 114 cm.
1910.29(b)(3): Guardrail systems are capable of withstanding, without failure, a force of at least 890 N applied in a downward or outward direction within 5 cm of the top edge, at any point along the top rail.
One important distinction of OSHA 1910 Subpart D is that a guardrail is what is on top of the platform, whereas a handrail is what is along the staircase. Handrails have a different height requirement than guardrails.
The guardrails must be on every open side of the platform. In instances where the platform is up against another vertical surface (such as the equipment being accessed), and that fully protects the opening, guardrails are not required on that side. In that case, it is still critical to ensure railing covers any gaps.
When you’re performing maintenance tasks, there is a good chance you will be setting tools, parts, and hardware on the floor beside you. In order to prevent a tools and parts falling off the platform and smacking a coworker on the head, 100 mm tall toe boards are required on all open sides of the platform (excluding openings). Guardrail systems should also be capable of withstanding 890 N of force applied in a downward or outward direction.