Sheet 25Mix-up sheet · Falls, ladders and scaffolds
Fall protection trigger heights: 6 feet, not 4
OSHA requires fall protection at 6 feet above a lower level in construction, under 29 CFR 1926.501. The 4-foot figure you will also hear on site belongs to general industry (29 CFR 1910.28). Two construction subparts set their own height on top of that: 10 feet for scaffolds and 15 feet for steel erection.
Both rule books protect people at an edge and draw the line at different heights. General industry, which covers plants, warehouses and fixed facilities, uses 4 feet. Construction uses 6 feet throughout Subpart M: unprotected sides and edges, leading edges, hoist areas, formwork and rebar, ramps and walkways, excavation edges, wall openings, and both low-slope and steep roofs. When someone quotes 4 feet for a construction edge, they are quoting the neighboring rule book.
The scaffold and steel-erection heights apply only inside Subpart L and Subpart R. Steel erection also lets connectors work up to two stories or 30 feet, whichever is less, before they need a system (29 CFR 1926.760(b)). A worker who steps off the scaffold onto a floor deck is back under the 6-foot rule of Subpart M. Fixed ladders have a 24-foot trigger of their own, covered with the 4-to-1 rule on ladder rules, and the rest of the access topics are on falls, ladders and scaffolds.
Talking point 02
Trigger heights on one line
Heights above a lower level at which each rule first requires protection. Only the 4 ft mark comes from general industry.scroll →Talking point 03
Below 6 feet still has rules
Holes
Protection against falling through applies to holes more than 6 feet above a lower level (29 CFR 1926.501(b)(4)), yet a hole 2 inches or more across needs a cover at any height, against trips, step-ins and dropped tools. Covers carry twice the load placed on them, or twice the heaviest axle load in a roadway.
Dangerous equipment
Above equipment that can injure on contact, such as a mixer or other machinery, a guardrail or equipment guard is required at any height (29 CFR 1926.501(b)(8)).
Overhand bricklaying
A mason who reaches more than 10 inches below the working surface needs a guardrail, a net or a personal fall arrest system; a controlled access zone alone does not cover the reach.
Roof warning lines
On a low-slope roof a warning line stands at least 6 feet back from the edge, and at least 10 feet back on edges perpendicular to the direction mechanical equipment travels.
Talking point 04
The hardware numbers that come with the trigger
Subpart M system criteria, 29 CFR 1926.502scroll →
Component
Requirement
Worth knowing
Guardrail top rail
42 in, plus or minus 3 in
A 200 lb test load may not push it below 39 in
Midrail
About halfway up
Holds 150 lb; not needed behind a wall or parapet at least 21 in high
Toeboard
3.5 in minimum
Withstands 50 lb
Fall arrest anchorage
5,000 lb per worker attached
Two workers on one anchor means 10,000 lb, unless a qualified person designs it with a safety factor of 2
Picture the edge, and the people working below it, before you pick an answer.
Card 1 of 6 · 0 right
Card 1
A supervisor finds a loose, unmarked sheet of plywood lying over a 3-foot-square floor hole on an upper deck. What should the supervisor require?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: hole covers must be secured so they cannot be displaced and marked HOLE or COVER, in addition to carrying the expected load.
BBright paint warns but does not stop the sheet from being kicked aside, and the cover still lacks a HOLE or COVER marking.
CA cone draws attention, yet it can be moved and leaves the plywood unsecured over the opening.
DA bigger sheet overlaps more but is still loose and unmarked, so it can shift or be carried off as scrap.
Card 2
What is the PRIMARY purpose of the toeboard on a scaffold platform?
Pick an answer. A short note for each option, A to D, appears here.
AA midrail sits at mid-height between the top rail and the platform; a toeboard is a low barrier at the platform edge.
BCorrect: Toeboards are falling-object protection, required where people below could be struck by tools or materials sliding off the platform.
CPlanks are kept in place by cleats or by extending past their supports, not by the toeboard.
DGuardrail and toeboard components are never used as fall-arrest anchorages, which have their own strength requirements.
Card 3
During a rushed deck pour, a supervisor sees a worker remove a hole cover to pass a pump hose through, leaving the opening unprotected. What should the supervisor do FIRST?
Pick an answer. A short note for each option, A to D, appears here.
AA reminder tomorrow does nothing about the open hole that workers are walking around right now.
BFinishing the pour first keeps workers exposed to an unprotected floor opening at the moment production pressure is highest.
CA debrief is useful follow-up, but recording the deviation does not protect anyone from the open hole now.
DCorrect: An unprotected hole is an immediate fall hazard, so it is protected again, for example with a cover cut for the hose, before work near it continues.
Card 4
HVAC installers will work for several days within 4 ft of an unprotected edge on a flat roof 20 ft above grade. Which control ranks HIGHEST in the hierarchy of controls?
Pick an answer. A short note for each option, A to D, appears here.
AA personal fall arrest system is PPE that only limits injury after a fall begins, so it ranks below a guardrail.
BTraining is an administrative control that depends on every installer staying alert near the edge.
CA safety monitor is an administrative control, and that system is permitted only in limited low-slope roof situations.
DCorrect: A guardrail is an engineering control that protects everyone at the edge passively, without depending on each worker's actions.
Card 5
An ironworker plans to clip a 6-foot shock-absorbing lanyard to an anchor at the level of the worker's boots, because nothing overhead is available. What is the main problem with this setup?
Pick an answer. A short note for each option, A to D, appears here.
AReach is a planning question. The safety problem is how far the worker drops before the lanyard starts to arrest.
BLow anchors are not banned outright. The rule is that the system must keep free fall to 6 feet or less.
CCorrect: Anchored at the boots, the worker falls the lanyard length plus the D-ring height, about 11 feet, which breaks the 6-foot free-fall limit.
DThe absorber still deploys, but only after a long free fall, with more force and more clearance needed below.
Card 6
A newly hired worker finds that the only harness available on site is too large to adjust snugly. The task requires personal fall arrest. What should the supervisor do?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: A harness must fit the wearer to work in a fall. The worker is not exposed until one that fits is provided.
BA harness that cannot be adjusted snugly can let the worker slip out or be injured during an arrest.
CBody belts have not been allowed for fall arrest since 1998.
DA spotter cannot stop a fall. The worker needs a properly fitted harness.