The height at which US workers must be protected from falls depends on the work: 6 ft in construction, 4 ft in general industry (factories, warehouses, maintenance), 10 ft on scaffolds and 15 ft in steel erection. Above those heights the employer must provide guardrails, safety nets or personal fall arrest systems. This page lists the trigger heights with their regulation numbers, the guardrail dimensions, and the limits a fall arrest system must meet, with a worked clearance example.
Fall protection trigger heights
| Work | Fall protection required at | 29 CFR section |
|---|---|---|
| Construction: unprotected sides and edges, roofs, holes, residential construction | 6 ft | 1926.501(b)(1), (4), (10), (11), (13) |
| Construction: scaffolds | more than 10 ft | 1926.451(g)(1) |
| Construction: steel erection | 15 ft (connectors and decking crews: over 15 ft up to 30 ft or two stories with specific rules) | 1926.760(a)(1), (b) |
| Construction: excavations hidden from view, wells and pits | 6 ft deep | 1926.501(b)(7) |
| General industry: walking-working surfaces, holes, dockboards, runways, stair landings | 4 ft | 1910.28(b)(1), (3), (4), (5), (11) |
| General industry: low-slope roofs | Within 6 ft of the edge: guardrail, net, travel restraint or fall arrest; 6 to 15 ft: the same, or a designated area for infrequent and temporary work; 15 ft or more: the same or a designated area, or none for infrequent and temporary work, with a work rule keeping people 15 ft back | 1910.28(b)(13) |
| General industry: fixed ladders | Over 24 ft: a ladder safety or personal fall arrest system | 1910.28(b)(9) |
| Any height: above dangerous equipment | Below 6 ft (construction) or 4 ft (general industry): guardrail or equipment guard; above: full fall protection | 1926.501(b)(8), 1910.28(b)(6) |
Guardrail requirements (construction)
| Item | Requirement | Section |
|---|---|---|
| Top rail height | 42 in, plus or minus 3 in (39 to 45 in) | 1926.502(b)(1) |
| Midrail | About halfway, where there is no wall or parapet at least 21 in high | 1926.502(b)(2) |
| Openings | No opening in the guardrail more than 19 in | 1926.502(b)(2)(iv) |
| Top rail strength | 200 lb in any outward or downward direction; top must not deflect below 39 in | 1926.502(b)(3)-(4) |
| Midrail strength | 150 lb | 1926.502(b)(5) |
Personal fall arrest system limits
| Item | Limit | Section |
|---|---|---|
| Maximum free fall | 6 ft, and never far enough to strike a lower level | 1926.502(d)(16)(iii) |
| Maximum arresting force | 1,800 lb with a body harness | 1926.502(d)(16)(ii) |
| Maximum deceleration distance | 3.5 ft | 1926.502(d)(16)(iv) |
| Anchorage | 5,000 lb per person attached, or designed with a safety factor of 2 under a qualified person | 1926.502(d)(15) |
| Lanyards and lifelines | 5,000 lb breaking strength | 1926.502(d)(9) |
| Snaphooks and D-rings | 5,000 lb tensile strength | 1926.502(d)(3) |
| Self-retracting lifelines limiting free fall to 2 ft | 3,000 lb tensile load | 1926.502(d)(12) |
How much clearance below do you need?
A fall arrest system only works if the worker stops before hitting the ground or a lower level, and OSHA requires exactly that (1926.502(d)(16)(iii)). Clearance is usually estimated by adding the free fall, the deceleration distance, the distance from the harness D-ring to the worker’s feet and a safety margin. The rows below use OSHA’s limits for the first two and common planning figures (labelled) for the rest; the equipment maker’s clearance chart for your exact lanyard or self-retracting lifeline always governs.
| System | Free fall | Deceleration | D-ring to feet (typical) | Safety margin (typical) | Clearance below the anchor level |
|---|---|---|---|---|---|
| 6 ft lanyard | 6 ft | 3.5 ft | 5 ft | 2 ft | 16.5 ft |
| 4 ft lanyard | 4 ft | 3.5 ft | 5 ft | 2 ft | 14.5 ft |
| 2 ft lanyard | 2 ft | 1.5 ft | 5 ft | 2 ft | 10.5 ft |
The 6 ft lanyard example shows why tying off at your feet on a low roof is not enough: with about 16.5 ft of clearance needed, a lanyard is useless on a single-storey roof unless it is anchored overhead or replaced by a self-retracting lifeline or a restraint system that stops you reaching the edge.
Residential construction
Since 2011 OSHA has applied the 6 ft rule to residential construction (1926.501(b)(13)) with the same options as other construction: guardrails, safety nets or personal fall arrest, or a written fall protection plan where those are infeasible. Roofers on a typical house are well above 6 ft at the eaves, so roof anchors with harnesses, or guardrails at the eaves, are the norm on professional jobs.
Frequently asked questions
At what height is fall protection required?
6 ft in construction (1926.501), 4 ft in general industry (1910.28), 10 ft on scaffolds (1926.451(g)) and 15 ft in steel erection (1926.760).
How high must a guardrail be under OSHA?
42 in plus or minus 3 in at the top rail in construction (1926.502(b)(1)), with a midrail about halfway; scaffold top rails are 38 to 45 in.
What is the maximum free fall distance?
6 ft, with deceleration of no more than 3.5 ft and a maximum arresting force of 1,800 lb in a body harness (1926.502(d)(16)).
How strong must a fall protection anchor be?
5,000 lb per person attached, or designed by a qualified person with a safety factor of at least 2 (1926.502(d)(15)).
Sources
- US federal regulations (29 CFR), read at law.cornell.edu; text cached 24 October 2026. Paraphrased with section numbers, not the legal text. 29 CFR 1926.501, 1926.502, 1926.451, 1926.760, 1910.28.
Last reviewed: 24 October 2026. Numbers in the tables are our arithmetic from the sources listed; code sections are summarised, not quoted. How we check our work: methodology and corrections. Spotted an error? Please let us know.