What is the interior lighting minimum?

• A. 500 LUX measured 1 m above the furnished floor in the middle of aisles
• B. 300 LUX at floor level
• C. 750 LUX at ceiling
• D. 200 LUX at 2 m above floor

Answer: (A)

The idea being tested is ensuring enough interior light where people move and work, so visibility and safety are maintained in the space. The specified minimum for interior lighting in aisles is 500 lux, measured 1 meter above the floor in the middle of the aisle. This location matters because it reflects the actual working and walking zone—eye level is typically around that height, and the center of the aisle represents a representative spot where people pass and glance at signs, objects, and equipment.

Why this is the best choice: 500 lux at 1 meter above the floor gives a dependable level of brightness for reading labels, spotting obstacles, and navigating safely, without overdoing energy use or creating glare. The measurement point ensures the reading corresponds to what a person experiences while moving through the space.

Why the other options don’t fit as well: 300 lux at floor level can underestimate the illuminance people actually experience since light at floor level doesn’t represent task or eye-level visibility, and shadows or reflections can skew perception. 750 lux at the ceiling isn’t how illuminance is assessed; measuring at the ceiling doesn’t reflect the light available at the user’s working plane, and it would overestimate practical visibility. 200 lux at 2 meters above the floor would be too dim for safe navigation and tasks in an aisle, since the measurement height is far above typical working sightlines and would not meet the required level.