Subpart D — the 4-foot rule people apply as 6.
General industry triggers fall protection at 4 feet. Construction triggers at 6. On a live campus with an active build-out, both numbers are in play on the same property — and the operations team routinely applies the wrong one.
Under 1910.28, general industry requires fall protection where an employee is exposed to a fall of 4 feet or more to a lower level. Under 1926.501, construction requires it at 6 feet. Your maintenance technician on a 5-foot platform is protected; the electrician on the same platform doing new install may be under 1926.
§ Where data center staff actually work at height
Roof mechanical. Chillers, condensers, dry coolers, exhaust fans — with roof edges that are frequently unprotected outside a designated walkway.
Catwalks and platforms over data halls and above containment.
Elevated cable tray — reached by ladder or lift, often in tight aisles.
Generator radiator platforms and enclosure roofs.
Cooling tower access, basins and fan decks — usually the worst combination of height, water and rotating equipment on the site.
Top-of-rack work from a ladder or platform in a live data hall.
§ Sections
| Section | Topic | Note |
|---|---|---|
| 1910.22 | General requirements — surfaces kept clean, orderly, sanitary, and maintained | Housekeeping in electrical rooms is a Subpart D issue as well as a 70E 130.8 one |
| 1910.23 | Ladders | Portable, fixed and mobile ladder stands. Fixed ladders over 24 ft require a personal fall arrest or ladder safety system |
| 1910.25 | Stairways | |
| 1910.26 | Dockboards | Loading dock — where every rack in the building arrived |
| 1910.27 | Scaffolds and rope descent systems | Facade access; anchorage certification required |
| 1910.28 | Duty to have fall protection | The 4-foot trigger and the specific situations |
| 1910.29 | Fall protection systems and falling object protection — criteria and practices | Guardrail, safety net, personal fall arrest specifications |
| 1910.30 | Training requirements | Before the employee is exposed, and retraining when conditions change |
§ The roof problem
A data center roof is a working floor. It carries chillers, condensers, dry coolers, exhaust and often PV — all of which need routine maintenance, all of which sit on a surface with an unprotected edge somewhere.
The common arrangement is a designated walkway with warning lines, and fall protection required outside it. That works only if the walkway is marked, the rule is trained, and the equipment is actually reachable from inside the line. It frequently is not — and the technician steps outside without a plan.
Where PV is present, Article 390 lands on the same roof at the same time: an energized DC array and an unprotected edge, worked by the same person.
Fall protection equipment on site, in date, and unusable because there is no certified anchorage within reach of the equipment that needs servicing. Anchorage points are a design decision that has to be made before the roof is loaded with mechanical plant.
Full-practice safety, not just electrical
Rick is a CSP with 35 years across the whole EHS practice — the roof, the yard and the switchgear room.
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