Site Lighting Toolbox Talk

The talk, read this out

It gets dark at half four soon. Who here knows what the legal minimum light level is for the work we do, and in what unit?

There is a table in the regulations, Table D-3, and it sets minimum illumination intensities in foot candles. Construction areas, ramps, runways, corridors, offices, shops and storage areas shall be lighted to not less than those minimums while any work is in progress. While any work is in progress, which includes the last hour when people are packing up.

The numbers are low and worth hearing so nobody imagines they are being generous. General construction area lighting: 5 foot candles. General construction areas, concrete placement, excavation and waste areas, access ways, active storage areas, loading platforms, refueling and field maintenance areas: 3.

Indoors, warehouses, corridors, hallways and exitways: 5. Tunnels, shafts and general underground work areas: 5, and the exception, a minimum of 10 foot candles at tunnel and shaft heading during drilling, mucking and scaling.

General construction plant and shops, meaning batch plants, screening plants, mechanical and electrical equipment rooms, carpenter shops, rigging lofts, active store rooms, mess halls and indoor toilets and workrooms: 10. First aid stations, infirmaries and offices: 30.

Five for the general area and thirty for the office is the comparison to sit with. The place where somebody does paperwork is required to be six times brighter than the place where somebody carries block down a ramp, and neither of those is a lot of light.

For anything not in that table the standard points at the American National Standard A11.1-1965, R1970, Practice for Industrial Lighting, for recommended values. That is the fallback, and on a real job it is the argument for asking rather than guessing.

So what this means at four in the afternoon in November. Task lighting at the face of the work, not one flood on a pole throwing everybody's shadow into their own cut. Light on the access route, the ramp and the stairs, which is where people get hurt walking out, not where they get hurt working.

And the lighting itself is temporary electrical equipment, which puts it under everything in the cords and GFCI talk. Every string, every festoon, every task light: guarded bulbs, no damaged insulation, kept up out of standing water, and on ground fault protection like anything else on a cord here.

Point at these before anybody starts

A talk delivered in a trailer is a meeting. Stand where the work is and put a hand on each of these.

• Whether there is any light at the actual face of the work or just overhead.
• The access route, stairs and ramps after dark, walked end to end.
• Every temporary light on a cord: guard on, cable sound, plug intact.
• Glare and shadow. Enough light aimed wrong is still not enough light.
• The first aid station and the office, which are the two places with a real number on them.
• What happens when the generator or the site power goes off, and who has a torch.

The rules that apply

• Construction areas, ramps, runways, corridors, offices, shops and storage areas shall be lighted to not less than the minimum illumination intensities listed in Table D-3 while any work is in progress.
• Table D-3 minimums in foot candles: 5 for general construction area lighting; 3 for general construction areas, concrete placement, excavation and waste areas, access ways, active storage areas, loading platforms, refueling and field maintenance areas; 5 indoors for warehouses, corridors, hallways and exitways.
• Tunnels, shafts and general underground work areas: 5 foot candles, with a minimum of 10 required at tunnel and shaft heading during drilling, mucking and scaling.
• General construction plant and shops: 10 foot candles. First aid stations, infirmaries and offices: 30 foot candles.
• For areas or operations not covered by Table D-3, refer to American National Standard A11.1-1965, R1970, Practice for Industrial Lighting, for recommended values of illumination.

Ask the crew

Three questions, answered out loud by name. This is the part that tells you whether anybody was listening.

• What is the minimum for a general construction area, and what is it for the office?
• Which area in the table has to be brighter than all the others, and why would that be?
• If it goes dark on the way out tonight, what is the route and is it lit?

Close with this

Nobody gets hurt by the dark. They get hurt by the thing in it that they did not see in time.

Questions people ask

What is a foot candle, in practice?

One lumen per square foot. As a rough feel, a bright overcast day outdoors is in the hundreds, a well lit office is 30 to 50, and 5 is dim enough that you can move safely but not inspect anything. Phone apps measure it approximately, and a proper light meter is cheap if the job is going to run into winter.

Does Table D-3 apply to night work specifically?

It applies while any work is in progress, so a night shift is squarely inside it and so is the last hour of a winter afternoon. The standard makes no distinction between light that is missing because the sun went down and light that was never there.

Who is responsible for lighting the access route?

Access ways carry a 3 foot candle minimum in Table D-3 in their own right, so they are not an afterthought to the work area. On a multi employer site that duty usually sits with the controlling contractor, which is worth settling out loud before the clocks change rather than after somebody falls down a ramp.

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