Guide to Emergency Lighting
In an emergency, proper lighting can point the way to safety. This is one reason why some local jurisdictions have mandated that Exit signs be located at waist height and illuminated. Lowering signs reduces the likelihood that during a fire it will be obscured by smoke. Proper illumination in work spaces have been shown to help reduce eye fatigue and having good illumination when working with various tools contributes to safety. In these various settings light is generally expressed in terms of lux units which measure the amount of light over an area.