Open area emergency lighting is required for spaces greater than 60 m², with a minimum of 0.5 lux, as specified in BS EN 1838. A risk assessment will determine if this is sufficient, particularly if process equipment causes obstructions.
The same standard of cleanliness applies as for the general lighting, so luminaires that are easy to wipe down.
High-risk task-area lighting is required where machinery, plant or processors need to be brought to a safe and stable state before the area is evacuated, so may be applicable to food production processes.
A minimum of 10% of the normal illuminance is required in these areas to allow the workforce to make machines and processes safe before they evacuate. The minimum duration is determined by the time required to make the machines or processes safe.
There is a specific recommendation in BS 5266-1 that kitchens should have a minimum of 15 lux on the isolators and switches to allow hobs, ovens and similar items to be safely switched off before evacuation.