Environmentally-friendly fireworks have been developed to reduce the amount of atmospheric pollution produced. Traditional fireworks are normally made using a charcoal and sulphur fuel, a perchlorate oxidiser to help with burning, plus binders, colourants and propellants. When ignited, the pyrotechnics are spectacular, but they emit large amounts of smoke, unused perchlorates and metal by-products from the colourants, all of which are contaminates. Eco-friendly fireworks have a clean burning, nitrogen-based fuel. This means a perchlorate oxidiser is not needed and because there is little smoke, only small amounts of metal salts are needed to produce the brilliantly coloured flames.