Halogen bulbs are a form of energy efficient lighting that use around 25 per cent less energy than traditional incandescent bulbs.
Like traditional bulbs, Halogen bulbs use a tungsten filament, but they use a halogen gas inside the bulb rather than argon or nitrogen, making the filament last longer.
Around half the size of traditional bulbs, they are most commonly used in fixed ceiling down-lighters.
It is expected that some lower-efficiency Halogen bulbs will be banned alongside incandescent bulbs under upcoming EU regulations, though the sale of higher efficiency models will still be permitted.