Flat, square surface-mounted luminaire. Die-cast aluminum fitting, powder-coated, plastic (polycarbonate) cover. With plastic lenses for area lighting. Operating device suitable for direct current, suitable for central emergency power supply. Luminaires with limited surface temperature in accordance with DIN EN 60598-2-24 for use in an environment in which deposits of conductive dust on the luminaire can be expected. Ball-proof in accordance with DIN 18032-3. Approved for use in the food and beverage industry.