Lux levels by area: what HSE's guidance asks for.

The short answer, area by area

Every row gives two figures: an average for the area as a whole, and a minimum for any single point in it. Measure against both.

HSE's own table, with all five rows and its notes, is on HSG38 lighting levels.

When the figure goes up

HSG38's lowest row, for corridors, circulation routes and lorry parks, considers safety only, on the basis that nobody there needs to see detail. HSE says that where someone has to see detail to recognise a hazard, or where a mistake could put someone else at risk, the figures for work requiring perception of detail apply instead: 200 lux average and 100 lux minimum.

So the same corridor can need a different figure depending on what happens in it. Choose the row by the work, and write down why you chose it.

Office lux levels

HSG38 lists offices under work requiring perception of detail: 200 lux average across the area, and 100 lux at the darkest point. Drawing offices sit a row higher, at 500 and 200.

Those are HSE's figures for avoiding eye strain and staying safe. The level an office lighting designer aims for is usually higher, and it comes from industry best practice. If your client's specification names a figure, measure against that and record where it came from.

Warehouse lux levels

HSG38 doesn't list warehouses, so the row depends on what happens in each part of the building.

• Aisles and routes where people and vehicles move: HSE's movement row, 20 average and 5 minimum. Where you judge the area hazardous, the next row up, 50 and 20.
• Picking, checking and paperwork, where people read labels or screens: that's seeing detail, so in our reading the perception of detail row applies, 200 and 100.
• Loading bays: HSE lists them, at 50 and 20.

HSG38 also limits how sharply the light may change between neighbouring areas, such as a storage area inside and a loading bay outside, so that people moving between them aren't caught out. That compares two areas rather than points within one.

Corridors, stairs and escape routes

HSE lists corridors and circulation routes in its movement row: 20 lux average, 5 lux minimum. It doesn't give stairs a row of their own, but it asks for particular attention to stairs, obstructions and changes of direction. Where a step or an obstruction has to be seen to be avoided, the rule in When the figure goes up applies.

Escape lighting, the lighting that takes over when the normal supply fails, is a separate matter. HSG38 refers to its own code of practice for those figures, and this page doesn't give them.

Kitchens

HSE lists kitchens under work requiring limited perception of detail: 100 lux average, 50 lux minimum.

Car parks and yards

HSE lists lorry parks in its movement row, at 20 and 5. For other workplace car parks and yards, that row is the nearest match in our reading, and the rule in When the figure goes up still applies where vehicles and people mix. Where parked vehicles block the light, HSE suggests lighting from overhead, high enough to keep shadows down.

Factories and workshops

HSG38 gives its own examples, which cover most of the range:

• bottling and canning plant: 50 average, 20 minimum
• assembling large components, potteries: 100 and 50
• sheet metal work, bookbinding: 200 and 100
• assembling electronic components, textile production: 500 and 200

Stations and rail

HSG38 is general workplace guidance. Rail operators set lighting levels for their own assets in their own standards. If you're surveying for one of them, measure against the figure their document gives. We don't reproduce those figures here.

Checking an area against these figures

1. Choose the row by the work done in the area, and note why.
2. Use a calibrated lux meter, not a phone. Why a phone app isn't enough.
3. Take readings at evenly spaced points across the whole area, corners and edges included.
4. Compare the average with the row's average figure, and the lowest single reading with its minimum.
5. Record each as at or above HSE's figure, or below it.

The full method is in How to do a lux survey, and What a lighting survey report should contain covers what to write down.

Source and licence

Figures and typical locations from HSG38, Lighting at work, second edition, Health and Safety Executive, 1997, summarised in our own words. Where an area isn't named by HSE, the row given is our reading and is marked as such. © Crown copyright. This page is not published or endorsed by HSE.

Contains public sector information published by the Health and Safety Executive and licensed under the Open Government Licence.