Nov
OSHA Jobsite Lighting Requirements: A Practical Guide to Temporary Construction Lighting
Temporary lighting is one of the first things a superintendent sets up on a new job and one of the easiest places to pick up a citation. OSHA sets minimum light levels for construction work in 29 CFR 1926.56, and separate electrical rules in Subpart K cover how temporary lights are guarded, hung and powered. This guide sums up both, then shows how to turn the numbers into a fixture count.
OSHA minimum light levels for construction (1926.56)
Table D-3 of 29 CFR 1926.56 sets the minimum illumination, in foot-candles, that must be kept wherever work is in progress. In summary:
| Foot-candles | Area or operation |
|---|---|
| 3 | General construction areas, concrete placement, excavation and waste areas, access ways, active storage areas, loading platforms, refueling and field maintenance areas |
| 5 | General construction area lighting; indoor warehouses, corridors, hallways and exitways; tunnels, shafts and general underground work areas (10 at tunnel and shaft headings during drilling, mucking and scaling) |
| 10 | General construction plant and shops: batch and screening plants, mechanical and electrical equipment rooms, carpenter shops, rigging lofts, active storerooms, living quarters, locker rooms, mess halls, indoor toilets and workrooms |
| 30 | First aid stations, infirmaries and offices |
These are minimums. Detailed work such as finish carpentry, electrical terminations or inspection usually needs more light than the table requires, and many general contractors set higher levels in their own site safety plans.
Electrical rules for temporary lights
OSHA’s construction electrical standard (29 CFR 1926.405) treats temporary lighting as temporary wiring. The main points for jobsite lights:
- All lamps for general illumination must be protected from accidental contact or breakage, typically with a cage or guard. Caged fixtures and stringers with snap-on cages are built for this. Metal-cased sockets must also be grounded.
- Temporary lights must not be hung by their electric cords unless the cord and light are designed to be suspended that way. Hang fixtures from their hooks or brackets, not from the cord.
- Flexible cords used with temporary and portable lights must be designed for hard or extra-hard usage, and cords must be protected from damage, such as sharp corners and projections. SJTW is a hard-usage cord type, and its “W” marks it for outdoor and wet locations.
- Under 29 CFR 1926.404(b)(1), 120-volt, single-phase, 15- and 20-amp receptacle outlets that are not part of the building’s permanent wiring need ground-fault circuit-interrupter (GFCI) protection, or the employer must run an assured equipment grounding conductor program.
Check the current regulation text and any state-plan requirements before relying on a summary. Several states run their own OSHA plans with additional rules.
Turning foot-candles into a fixture count
One foot-candle is one lumen spread over one square foot. A quick planning estimate is:
Lumens needed = area (sq ft) × target foot-candles ÷ a utilization factor
The utilization factor allows for light that lands on walls, gets blocked or is lost to mounting height. For open temporary lighting on a jobsite, 0.5 is a reasonable starting assumption. Use a lower number for tall ceilings or cluttered areas.
Example: a 5,000 sq ft open floor that needs 5 foot-candles needs about 5,000 × 5 ÷ 0.5 = 50,000 lumens. That is a planning number, not a guarantee. Always confirm with a light meter once the lights are up, especially at stairways, ladders and floor openings.
Choosing the light for each area
- Open floors, stairwells and corridors: string lights spread light evenly along a run. The SL10-100 carries ten caged 12W LED lamps on 100 ft of 14/2 SJTW cord, and the SL Series collection lists the full stringer range.
- Work areas that need more light in one place: a caged LED work light such as the CM7-100 (100W, 14,000 lumens, 120–277V) puts a lot of light where a crew is working.
- Warehouses, shops and tall spaces: high-ceiling areas covered by the 10 foot-candle shop row are often easier to light with high bays. See the UFO Series.
A quick jobsite lighting checklist
- Measure light levels at the work surface with a meter, not by eye.
- Re-check after each phase: new walls and ceilings change how light spreads.
- Keep every lamp guarded, and replace broken cages straight away.
- Hang lights from their hooks, never from the cord.
- Run temporary lighting on GFCI-protected circuits.
- Keep stairways, exits and floor openings lit at all times.
Need help sizing temporary lighting for a project? Request a quote with your floor area and phase schedule, or browse temporary lighting.
