What top-edge height is generally required for construction guardrail systems?
Correct Answer
B) 42 in. plus or minus 3 in.
Construction guardrail top edges are generally 42 inches plus or minus 3 inches above the walking-working level.
Why This Is the Correct Answer
Construction guardrail top edges are generally 42 inches plus or minus 3 inches above the walking-working level.
Why the Other Options Are Wrong
Option A: 30 in. plus or minus 3 in.
Choice A gives 30 in. plus or minus 3 in. Its specific error: 30 in. plus or minus 3 in. is the wrong OSHA fall-protection number for the item asked.
Option C: 48 in. minimum with no tolerance
In general project requirements, 48 in. minimum with no tolerance is the wrong selection for Guardrail height tolerance: 48 in. minimum with no tolerance is the wrong OSHA fall-protection number for the item asked.
Option D: Only waist height of the worker
The trap in D is Only waist height of the worker. That selection is wrong because it tries to bypass the Guardrail height tolerance checkpoint.
Memory Technique
File guardrail height tolerance under a switch: condition first, number or duty second, answer 42 in. plus or minus 3 in.
Reference Hint
Open 29 CFR Part 1926 (OSHA Construction Standards), 1926-2023 / PSI OSHA Excerpts 2025; use 29 CFR 1926 Subpart M - §1926.502(b) to confirm that Construction guardrail top edges are generally 42 inches plus or minus 3 inches above the walking-working level.
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