Classification of tungsten halogen bulbs as halogen lamps: excluded from nil-rate treatment and subject to standard duty. Tungsten halogen bulbs are defined separately in the Indian Standard Specifications as gas-filled lamps containing halogen gas and differ from general gas-filled lamps; therefore they are not eligible for the nil-rate concession under S. No. 4 and 5 and must be treated under the notification provision covering other bulbs, attracting the duty specified for that category.